package libpod import ( "bufio" "bytes" "context" "fmt" "io" "io/ioutil" "os" "path/filepath" "strconv" "strings" "time" metadata "github.com/checkpoint-restore/checkpointctl/lib" "github.com/containers/buildah/copier" butil "github.com/containers/buildah/util" "github.com/containers/podman/v3/libpod/define" "github.com/containers/podman/v3/libpod/events" "github.com/containers/podman/v3/pkg/cgroups" "github.com/containers/podman/v3/pkg/ctime" "github.com/containers/podman/v3/pkg/hooks" "github.com/containers/podman/v3/pkg/hooks/exec" "github.com/containers/podman/v3/pkg/rootless" "github.com/containers/podman/v3/pkg/selinux" "github.com/containers/podman/v3/pkg/util" "github.com/containers/storage" "github.com/containers/storage/pkg/archive" "github.com/containers/storage/pkg/idtools" "github.com/containers/storage/pkg/mount" "github.com/coreos/go-systemd/v22/daemon" securejoin "github.com/cyphar/filepath-securejoin" spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/opencontainers/runtime-tools/generate" "github.com/opencontainers/selinux/go-selinux/label" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) const ( // name of the directory holding the artifacts artifactsDir = "artifacts" execDirPermission = 0755 preCheckpointDir = "pre-checkpoint" ) // rootFsSize gets the size of the container's root filesystem // A container FS is split into two parts. The first is the top layer, a // mutable layer, and the rest is the RootFS: the set of immutable layers // that make up the image on which the container is based. func (c *Container) rootFsSize() (int64, error) { if c.config.Rootfs != "" { return 0, nil } if c.runtime.store == nil { return 0, nil } container, err := c.runtime.store.Container(c.ID()) if err != nil { return 0, err } // Ignore the size of the top layer. The top layer is a mutable RW layer // and is not considered a part of the rootfs rwLayer, err := c.runtime.store.Layer(container.LayerID) if err != nil { return 0, err } layer, err := c.runtime.store.Layer(rwLayer.Parent) if err != nil { return 0, err } size := int64(0) for layer.Parent != "" { layerSize, err := c.runtime.store.DiffSize(layer.Parent, layer.ID) if err != nil { return size, errors.Wrapf(err, "getting diffsize of layer %q and its parent %q", layer.ID, layer.Parent) } size += layerSize layer, err = c.runtime.store.Layer(layer.Parent) if err != nil { return 0, err } } // Get the size of the last layer. Has to be outside of the loop // because the parent of the last layer is "", and lstore.Get("") // will return an error. layerSize, err := c.runtime.store.DiffSize(layer.Parent, layer.ID) return size + layerSize, err } // rwSize gets the size of the mutable top layer of the container. func (c *Container) rwSize() (int64, error) { if c.config.Rootfs != "" { var size int64 err := filepath.Walk(c.config.Rootfs, func(path string, info os.FileInfo, err error) error { if err != nil { return err } size += info.Size() return nil }) return size, err } container, err := c.runtime.store.Container(c.ID()) if err != nil { return 0, err } // The top layer of a container is // the only readable/writeable layer, all others are immutable. rwLayer, err := c.runtime.store.Layer(container.LayerID) if err != nil { return 0, err } // Get the size of the top layer by calculating the size of the diff // between the layer and its parent. return c.runtime.store.DiffSize(rwLayer.Parent, rwLayer.ID) } // bundlePath returns the path to the container's root filesystem - where the OCI spec will be // placed, amongst other things func (c *Container) bundlePath() string { return c.config.StaticDir } // ControlSocketPath returns the path to the containers control socket for things like tty // resizing func (c *Container) ControlSocketPath() string { return filepath.Join(c.bundlePath(), "ctl") } // CheckpointPath returns the path to the directory containing the checkpoint func (c *Container) CheckpointPath() string { return filepath.Join(c.bundlePath(), metadata.CheckpointDirectory) } // PreCheckpointPath returns the path to the directory containing the pre-checkpoint-images func (c *Container) PreCheckPointPath() string { return filepath.Join(c.bundlePath(), preCheckpointDir) } // AttachSocketPath retrieves the path of the container's attach socket func (c *Container) AttachSocketPath() (string, error) { return c.ociRuntime.AttachSocketPath(c) } // exitFilePath gets the path to the container's exit file func (c *Container) exitFilePath() (string, error) { return c.ociRuntime.ExitFilePath(c) } // Wait for the container's exit file to appear. // When it does, update our state based on it. func (c *Container) waitForExitFileAndSync() error { exitFile, err := c.exitFilePath() if err != nil { return err } chWait := make(chan error) defer close(chWait) _, err = WaitForFile(exitFile, chWait, time.Second*5) if err != nil { // Exit file did not appear // Reset our state c.state.ExitCode = -1 c.state.FinishedTime = time.Now() c.state.State = define.ContainerStateStopped if err2 := c.save(); err2 != nil { logrus.Errorf("Error saving container %s state: %v", c.ID(), err2) } return err } if err := c.checkExitFile(); err != nil { return err } return c.save() } // Handle the container exit file. // The exit file is used to supply container exit time and exit code. // This assumes the exit file already exists. func (c *Container) handleExitFile(exitFile string, fi os.FileInfo) error { c.state.FinishedTime = ctime.Created(fi) statusCodeStr, err := ioutil.ReadFile(exitFile) if err != nil { return errors.Wrapf(err, "failed to read exit file for container %s", c.ID()) } statusCode, err := strconv.Atoi(string(statusCodeStr)) if err != nil { return errors.Wrapf(err, "error converting exit status code (%q) for container %s to int", c.ID(), statusCodeStr) } c.state.ExitCode = int32(statusCode) oomFilePath := filepath.Join(c.bundlePath(), "oom") if _, err = os.Stat(oomFilePath); err == nil { c.state.OOMKilled = true } c.state.Exited = true // Write an event for the container's death c.newContainerExitedEvent(c.state.ExitCode) return nil } func (c *Container) shouldRestart() bool { // If we did not get a restart policy match, return false // Do the same if we're not a policy that restarts. if !c.state.RestartPolicyMatch || c.config.RestartPolicy == define.RestartPolicyNo || c.config.RestartPolicy == define.RestartPolicyNone { return false } // If we're RestartPolicyOnFailure, we need to check retries and exit // code. if c.config.RestartPolicy == define.RestartPolicyOnFailure { if c.state.ExitCode == 0 { return false } // If we don't have a max retries set, continue if c.config.RestartRetries > 0 { if c.state.RestartCount >= c.config.RestartRetries { return false } } } return true } // Handle container restart policy. // This is called when a container has exited, and was not explicitly stopped by // an API call to stop the container or pod it is in. func (c *Container) handleRestartPolicy(ctx context.Context) (_ bool, retErr error) { if !c.shouldRestart() { return false, nil } logrus.Debugf("Restarting container %s due to restart policy %s", c.ID(), c.config.RestartPolicy) // Need to check if dependencies are alive. if err := c.checkDependenciesAndHandleError(); err != nil { return false, err } // Is the container running again? // If so, we don't have to do anything if c.ensureState(define.ContainerStateRunning, define.ContainerStatePaused) { return false, nil } else if c.state.State == define.ContainerStateUnknown { return false, errors.Wrapf(define.ErrInternal, "invalid container state encountered in restart attempt!") } c.newContainerEvent(events.Restart) // Increment restart count c.state.RestartCount++ logrus.Debugf("Container %s now on retry %d", c.ID(), c.state.RestartCount) if err := c.save(); err != nil { return false, err } defer func() { if retErr != nil { if err := c.cleanup(ctx); err != nil { logrus.Errorf("error cleaning up container %s: %v", c.ID(), err) } } }() if err := c.prepare(); err != nil { return false, err } // setup slirp4netns again because slirp4netns will die when conmon exits if c.config.NetMode.IsSlirp4netns() { err := c.runtime.setupSlirp4netns(c) if err != nil { return false, err } } if c.state.State == define.ContainerStateStopped { // Reinitialize the container if we need to if err := c.reinit(ctx, true); err != nil { return false, err } } else if c.ensureState(define.ContainerStateConfigured, define.ContainerStateExited) { // Initialize the container if err := c.init(ctx, true); err != nil { return false, err } } if err := c.start(); err != nil { return false, err } return true, nil } // Ensure that the container is in a specific state or state. // Returns true if the container is in one of the given states, // or false otherwise. func (c *Container) ensureState(states ...define.ContainerStatus) bool { for _, state := range states { if state == c.state.State { return true } } return false } // Sync this container with on-disk state and runtime status // Should only be called with container lock held // This function should suffice to ensure a container's state is accurate and // it is valid for use. func (c *Container) syncContainer() error { if err := c.runtime.state.UpdateContainer(c); err != nil { return err } // If runtime knows about the container, update its status in runtime // And then save back to disk if c.ensureState(define.ContainerStateCreated, define.ContainerStateRunning, define.ContainerStateStopped, define.ContainerStatePaused) { oldState := c.state.State if err := c.checkExitFile(); err != nil { return err } // Only save back to DB if state changed if c.state.State != oldState { // Check for a restart policy match if c.config.RestartPolicy != define.RestartPolicyNone && c.config.RestartPolicy != define.RestartPolicyNo && (oldState == define.ContainerStateRunning || oldState == define.ContainerStatePaused) && (c.state.State == define.ContainerStateStopped || c.state.State == define.ContainerStateExited) && !c.state.StoppedByUser { c.state.RestartPolicyMatch = true } if err := c.save(); err != nil { return err } } } if !c.valid { return errors.Wrapf(define.ErrCtrRemoved, "container %s is not valid", c.ID()) } return nil } func (c *Container) setupStorageMapping(dest, from *storage.IDMappingOptions) { if c.config.Rootfs != "" { return } *dest = *from if dest.AutoUserNs { overrides := c.getUserOverrides() dest.AutoUserNsOpts.PasswdFile = overrides.ContainerEtcPasswdPath dest.AutoUserNsOpts.GroupFile = overrides.ContainerEtcGroupPath if c.config.User != "" { initialSize := uint32(0) parts := strings.Split(c.config.User, ":") for _, p := range parts { s, err := strconv.ParseUint(p, 10, 32) if err == nil && uint32(s) > initialSize { initialSize = uint32(s) } } dest.AutoUserNsOpts.InitialSize = initialSize + 1 } } else if c.config.Spec.Linux != nil { dest.UIDMap = nil for _, r := range c.config.Spec.Linux.UIDMappings { u := idtools.IDMap{ ContainerID: int(r.ContainerID), HostID: int(r.HostID), Size: int(r.Size), } dest.UIDMap = append(dest.UIDMap, u) } dest.GIDMap = nil for _, r := range c.config.Spec.Linux.GIDMappings { g := idtools.IDMap{ ContainerID: int(r.ContainerID), HostID: int(r.HostID), Size: int(r.Size), } dest.GIDMap = append(dest.GIDMap, g) } dest.HostUIDMapping = false dest.HostGIDMapping = false } } // Create container root filesystem for use func (c *Container) setupStorage(ctx context.Context) error { if !c.valid { return errors.Wrapf(define.ErrCtrRemoved, "container %s is not valid", c.ID()) } if c.state.State != define.ContainerStateConfigured { return errors.Wrapf(define.ErrCtrStateInvalid, "container %s must be in Configured state to have storage set up", c.ID()) } // Need both an image ID and image name, plus a bool telling us whether to use the image configuration if c.config.Rootfs == "" && (c.config.RootfsImageID == "" || c.config.RootfsImageName == "") { return errors.Wrapf(define.ErrInvalidArg, "must provide image ID and image name to use an image") } options := storage.ContainerOptions{ IDMappingOptions: storage.IDMappingOptions{ HostUIDMapping: true, HostGIDMapping: true, }, LabelOpts: c.config.LabelOpts, } if c.restoreFromCheckpoint && !c.config.Privileged { // If restoring from a checkpoint, the root file-system // needs to be mounted with the same SELinux labels as // it was mounted previously. if options.Flags == nil { options.Flags = make(map[string]interface{}) } options.Flags["ProcessLabel"] = c.config.ProcessLabel options.Flags["MountLabel"] = c.config.MountLabel } if c.config.Privileged { privOpt := func(opt string) bool { for _, privopt := range []string{"nodev", "nosuid", "noexec"} { if opt == privopt { return true } } return false } defOptions, err := storage.GetMountOptions(c.runtime.store.GraphDriverName(), c.runtime.store.GraphOptions()) if err != nil { return errors.Wrapf(err, "error getting default mount options") } var newOptions []string for _, opt := range defOptions { if !privOpt(opt) { newOptions = append(newOptions, opt) } } options.MountOpts = newOptions } options.Volatile = c.config.Volatile c.setupStorageMapping(&options.IDMappingOptions, &c.config.IDMappings) containerInfo, err := c.runtime.storageService.CreateContainerStorage(ctx, c.runtime.imageContext, c.config.RootfsImageName, c.config.RootfsImageID, c.config.Name, c.config.ID, options) if err != nil { return errors.Wrapf(err, "error creating container storage") } c.config.IDMappings.UIDMap = containerInfo.UIDMap c.config.IDMappings.GIDMap = containerInfo.GIDMap processLabel := containerInfo.ProcessLabel switch { case c.ociRuntime.SupportsKVM(): processLabel, err = selinux.KVMLabel(processLabel) if err != nil { return err } case c.config.Systemd: processLabel, err = selinux.InitLabel(processLabel) if err != nil { return err } } c.config.ProcessLabel = processLabel c.config.MountLabel = containerInfo.MountLabel c.config.StaticDir = containerInfo.Dir c.state.RunDir = containerInfo.RunDir if len(c.config.IDMappings.UIDMap) != 0 || len(c.config.IDMappings.GIDMap) != 0 { if err := os.Chown(containerInfo.RunDir, c.RootUID(), c.RootGID()); err != nil { return err } if err := os.Chown(containerInfo.Dir, c.RootUID(), c.RootGID()); err != nil { return err } } // Set the default Entrypoint and Command if containerInfo.Config != nil { // Set CMD in the container to the default configuration only if ENTRYPOINT is not set by the user. if c.config.Entrypoint == nil && c.config.Command == nil { c.config.Command = containerInfo.Config.Config.Cmd } if c.config.Entrypoint == nil { c.config.Entrypoint = containerInfo.Config.Config.Entrypoint } } artifacts := filepath.Join(c.config.StaticDir, artifactsDir) if err := os.MkdirAll(artifacts, 0755); err != nil { return errors.Wrap(err, "error creating artifacts directory") } return nil } // Tear down a container's storage prior to removal func (c *Container) teardownStorage() error { if c.ensureState(define.ContainerStateRunning, define.ContainerStatePaused) { return errors.Wrapf(define.ErrCtrStateInvalid, "cannot remove storage for container %s as it is running or paused", c.ID()) } artifacts := filepath.Join(c.config.StaticDir, artifactsDir) if err := os.RemoveAll(artifacts); err != nil { return errors.Wrapf(err, "error removing container %s artifacts %q", c.ID(), artifacts) } if err := c.cleanupStorage(); err != nil { return errors.Wrapf(err, "failed to cleanup container %s storage", c.ID()) } if err := c.runtime.storageService.DeleteContainer(c.ID()); err != nil { // If the container has already been removed, warn but do not // error - we wanted it gone, it is already gone. // Potentially another tool using containers/storage already // removed it? if errors.Cause(err) == storage.ErrNotAContainer || errors.Cause(err) == storage.ErrContainerUnknown { logrus.Infof("Storage for container %s already removed", c.ID()) return nil } return errors.Wrapf(err, "error removing container %s root filesystem", c.ID()) } return nil } // Reset resets state fields to default values. // It is performed before a refresh and clears the state after a reboot. // It does not save the results - assumes the database will do that for us. func resetState(state *ContainerState) { state.PID = 0 state.ConmonPID = 0 state.Mountpoint = "" state.Mounted = false if state.State != define.ContainerStateExited { state.State = define.ContainerStateConfigured } state.ExecSessions = make(map[string]*ExecSession) state.LegacyExecSessions = nil state.BindMounts = make(map[string]string) state.StoppedByUser = false state.RestartPolicyMatch = false state.RestartCount = 0 } // Refresh refreshes the container's state after a restart. // Refresh cannot perform any operations that would lock another container. // We cannot guarantee any other container has a valid lock at the time it is // running. func (c *Container) refresh() error { // Don't need a full sync, but we do need to update from the database to // pick up potentially-missing container state if err := c.runtime.state.UpdateContainer(c); err != nil { return err } if !c.valid { return errors.Wrapf(define.ErrCtrRemoved, "container %s is not valid - may have been removed", c.ID()) } // We need to get the container's temporary directory from c/storage // It was lost in the reboot and must be recreated dir, err := c.runtime.storageService.GetRunDir(c.ID()) if err != nil { return errors.Wrapf(err, "error retrieving temporary directory for container %s", c.ID()) } c.state.RunDir = dir if len(c.config.IDMappings.UIDMap) != 0 || len(c.config.IDMappings.GIDMap) != 0 { info, err := os.Stat(c.runtime.config.Engine.TmpDir) if err != nil { return err } if err := os.Chmod(c.runtime.config.Engine.TmpDir, info.Mode()|0111); err != nil { return err } root := filepath.Join(c.runtime.config.Engine.TmpDir, "containers-root", c.ID()) if err := os.MkdirAll(root, 0755); err != nil { return errors.Wrapf(err, "error creating userNS tmpdir for container %s", c.ID()) } if err := os.Chown(root, c.RootUID(), c.RootGID()); err != nil { return err } } // We need to pick up a new lock lock, err := c.runtime.lockManager.AllocateAndRetrieveLock(c.config.LockID) if err != nil { return errors.Wrapf(err, "error acquiring lock %d for container %s", c.config.LockID, c.ID()) } c.lock = lock // Try to delete any lingering IP allocations. // If this fails, just log and ignore. // I'm a little concerned that this is so far down in refresh() and we // could fail before getting to it - but the worst that would happen is // that Inspect() would return info on IPs we no longer own. if len(c.state.NetworkStatus) > 0 { if err := c.removeIPv4Allocations(); err != nil { logrus.Errorf("Error removing IP allocations for container %s: %v", c.ID(), err) } } c.state.NetworkStatus = nil if err := c.save(); err != nil { return errors.Wrapf(err, "error refreshing state for container %s", c.ID()) } // Remove ctl and attach files, which may persist across reboot if err := c.removeConmonFiles(); err != nil { return err } return nil } // Try and remove IP address allocations. Presently IPv4 only. // Should be safe as rootless because NetworkStatus should only be populated if // CNI is running. func (c *Container) removeIPv4Allocations() error { cniNetworksDir, err := getCNINetworksDir() if err != nil { return err } if len(c.state.NetworkStatus) == 0 { return nil } cniDefaultNetwork := "" if c.runtime.netPlugin != nil { cniDefaultNetwork = c.runtime.netPlugin.GetDefaultNetworkName() } networks, _, err := c.networks() if err != nil { return err } if len(networks) != len(c.state.NetworkStatus) { return errors.Wrapf(define.ErrInternal, "network mismatch: asked to join %d CNI networks but got %d CNI results", len(networks), len(c.state.NetworkStatus)) } for index, result := range c.state.NetworkStatus { for _, ctrIP := range result.IPs { if ctrIP.Version != "4" { continue } candidate := "" if len(networks) > 0 { // CNI returns networks in order we passed them. // So our index into results should be our index // into networks. candidate = filepath.Join(cniNetworksDir, networks[index], ctrIP.Address.IP.String()) } else { candidate = filepath.Join(cniNetworksDir, cniDefaultNetwork, ctrIP.Address.IP.String()) } logrus.Debugf("Going to try removing IP address reservation file %q for container %s", candidate, c.ID()) if err := os.Remove(candidate); err != nil && !os.IsNotExist(err) { return errors.Wrapf(err, "error removing CNI IP reservation file %q for container %s", candidate, c.ID()) } } } return nil } // Remove conmon attach socket and terminal resize FIFO // This is necessary for restarting containers func (c *Container) removeConmonFiles() error { // Files are allowed to not exist, so ignore ENOENT attachFile, err := c.AttachSocketPath() if err != nil { return errors.Wrapf(err, "failed to get attach socket path for container %s", c.ID()) } if err := os.Remove(attachFile); err != nil && !os.IsNotExist(err) { return errors.Wrapf(err, "error removing container %s attach file", c.ID()) } ctlFile := filepath.Join(c.bundlePath(), "ctl") if err := os.Remove(ctlFile); err != nil && !os.IsNotExist(err) { return errors.Wrapf(err, "error removing container %s ctl file", c.ID()) } winszFile := filepath.Join(c.bundlePath(), "winsz") if err := os.Remove(winszFile); err != nil && !os.IsNotExist(err) { return errors.Wrapf(err, "error removing container %s winsz file", c.ID()) } oomFile := filepath.Join(c.bundlePath(), "oom") if err := os.Remove(oomFile); err != nil && !os.IsNotExist(err) { return errors.Wrapf(err, "error removing container %s OOM file", c.ID()) } // Remove the exit file so we don't leak memory in tmpfs exitFile, err := c.exitFilePath() if err != nil { return err } if err := os.Remove(exitFile); err != nil && !os.IsNotExist(err) { return errors.Wrapf(err, "error removing container %s exit file", c.ID()) } return nil } func (c *Container) export(path string) error { mountPoint := c.state.Mountpoint if !c.state.Mounted { containerMount, err := c.runtime.store.Mount(c.ID(), c.config.MountLabel) if err != nil { return errors.Wrapf(err, "error mounting container %q", c.ID()) } mountPoint = containerMount defer func() { if _, err := c.runtime.store.Unmount(c.ID(), false); err != nil { logrus.Errorf("error unmounting container %q: %v", c.ID(), err) } }() } input, err := archive.Tar(mountPoint, archive.Uncompressed) if err != nil { return errors.Wrapf(err, "error reading container directory %q", c.ID()) } outFile, err := os.Create(path) if err != nil { return errors.Wrapf(err, "error creating file %q", path) } defer outFile.Close() _, err = io.Copy(outFile, input) return err } // Get path of artifact with a given name for this container func (c *Container) getArtifactPath(name string) string { return filepath.Join(c.config.StaticDir, artifactsDir, name) } // Used with Wait() to determine if a container has exited func (c *Container) isStopped() (bool, int32, error) { if !c.batched { c.lock.Lock() defer c.lock.Unlock() } err := c.syncContainer() if err != nil { return true, -1, err } return !c.ensureState(define.ContainerStateRunning, define.ContainerStatePaused, define.ContainerStateStopping), c.state.ExitCode, nil } // save container state to the database func (c *Container) save() error { if err := c.runtime.state.SaveContainer(c); err != nil { return errors.Wrapf(err, "error saving container %s state", c.ID()) } return nil } // Checks the container is in the right state, then initializes the container in preparation to start the container. // If recursive is true, each of the containers dependencies will be started. // Otherwise, this function will return with error if there are dependencies of this container that aren't running. func (c *Container) prepareToStart(ctx context.Context, recursive bool) (retErr error) { // Container must be created or stopped to be started if !c.ensureState(define.ContainerStateConfigured, define.ContainerStateCreated, define.ContainerStateStopped, define.ContainerStateExited) { return errors.Wrapf(define.ErrCtrStateInvalid, "container %s must be in Created or Stopped state to be started", c.ID()) } if !recursive { if err := c.checkDependenciesAndHandleError(); err != nil { return err } } else { if err := c.startDependencies(ctx); err != nil { return err } } defer func() { if retErr != nil { if err := c.cleanup(ctx); err != nil { logrus.Errorf("error cleaning up container %s: %v", c.ID(), err) } } }() if err := c.prepare(); err != nil { return err } if c.state.State == define.ContainerStateStopped { // Reinitialize the container if we need to if err := c.reinit(ctx, false); err != nil { return err } } else if c.ensureState(define.ContainerStateConfigured, define.ContainerStateExited) { // Or initialize it if necessary if err := c.init(ctx, false); err != nil { return err } } return nil } // checks dependencies are running and prints a helpful message func (c *Container) checkDependenciesAndHandleError() error { notRunning, err := c.checkDependenciesRunning() if err != nil { return errors.Wrapf(err, "error checking dependencies for container %s", c.ID()) } if len(notRunning) > 0 { depString := strings.Join(notRunning, ",") return errors.Wrapf(define.ErrCtrStateInvalid, "some dependencies of container %s are not started: %s", c.ID(), depString) } return nil } // Recursively start all dependencies of a container so the container can be started. func (c *Container) startDependencies(ctx context.Context) error { depCtrIDs := c.Dependencies() if len(depCtrIDs) == 0 { return nil } depVisitedCtrs := make(map[string]*Container) if err := c.getAllDependencies(depVisitedCtrs); err != nil { return errors.Wrapf(err, "error starting dependency for container %s", c.ID()) } // Because of how Go handles passing slices through functions, a slice cannot grow between function calls // without clunky syntax. Circumnavigate this by translating the map to a slice for buildContainerGraph depCtrs := make([]*Container, 0) for _, ctr := range depVisitedCtrs { depCtrs = append(depCtrs, ctr) } // Build a dependency graph of containers graph, err := BuildContainerGraph(depCtrs) if err != nil { return errors.Wrapf(err, "error generating dependency graph for container %s", c.ID()) } // If there are no containers without dependencies, we can't start // Error out if len(graph.noDepNodes) == 0 { // we have no dependencies that need starting, go ahead and return if len(graph.nodes) == 0 { return nil } return errors.Wrapf(define.ErrNoSuchCtr, "All dependencies have dependencies of %s", c.ID()) } ctrErrors := make(map[string]error) ctrsVisited := make(map[string]bool) // Traverse the graph beginning at nodes with no dependencies for _, node := range graph.noDepNodes { startNode(ctx, node, false, ctrErrors, ctrsVisited, true) } if len(ctrErrors) > 0 { logrus.Errorf("error starting some container dependencies") for _, e := range ctrErrors { logrus.Errorf("%q", e) } return errors.Wrapf(define.ErrInternal, "error starting some containers") } return nil } // getAllDependencies is a precursor to starting dependencies. // To start a container with all of its dependencies, we need to recursively find all dependencies // a container has, as well as each of those containers' dependencies, and so on // To do so, keep track of containers already visited (so there aren't redundant state lookups), // and recursively search until we have reached the leafs of every dependency node. // Since we need to start all dependencies for our original container to successfully start, we propagate any errors // in looking up dependencies. // Note: this function is currently meant as a robust solution to a narrow problem: start an infra-container when // a container in the pod is run. It has not been tested for performance past one level, so expansion of recursive start // must be tested first. func (c *Container) getAllDependencies(visited map[string]*Container) error { depIDs := c.Dependencies() if len(depIDs) == 0 { return nil } for _, depID := range depIDs { if _, ok := visited[depID]; !ok { dep, err := c.runtime.state.Container(depID) if err != nil { return err } status, err := dep.State() if err != nil { return err } // if the dependency is already running, we can assume its dependencies are also running // so no need to add them to those we need to start if status != define.ContainerStateRunning { visited[depID] = dep if err := dep.getAllDependencies(visited); err != nil { return err } } } } return nil } // Check if a container's dependencies are running // Returns a []string containing the IDs of dependencies that are not running func (c *Container) checkDependenciesRunning() ([]string, error) { deps := c.Dependencies() notRunning := []string{} // We were not passed a set of dependency containers // Make it ourselves depCtrs := make(map[string]*Container, len(deps)) for _, dep := range deps { // Get the dependency container depCtr, err := c.runtime.state.Container(dep) if err != nil { return nil, errors.Wrapf(err, "error retrieving dependency %s of container %s from state", dep, c.ID()) } // Check the status state, err := depCtr.State() if err != nil { return nil, errors.Wrapf(err, "error retrieving state of dependency %s of container %s", dep, c.ID()) } if state != define.ContainerStateRunning { notRunning = append(notRunning, dep) } depCtrs[dep] = depCtr } return notRunning, nil } func (c *Container) completeNetworkSetup() error { var outResolvConf []string netDisabled, err := c.NetworkDisabled() if err != nil { return err } if !c.config.PostConfigureNetNS || netDisabled { return nil } if err := c.syncContainer(); err != nil { return err } if c.config.NetMode.IsSlirp4netns() { return c.runtime.setupSlirp4netns(c) } if err := c.runtime.setupNetNS(c); err != nil { return err } state := c.state // collect any dns servers that cni tells us to use (dnsname) for _, cni := range state.NetworkStatus { if cni.DNS.Nameservers != nil { for _, server := range cni.DNS.Nameservers { outResolvConf = append(outResolvConf, fmt.Sprintf("nameserver %s", server)) } } } // check if we have a bindmount for /etc/hosts if hostsBindMount, ok := state.BindMounts["/etc/hosts"]; ok && len(c.cniHosts()) > 0 { ctrHostPath := filepath.Join(c.state.RunDir, "hosts") if hostsBindMount == ctrHostPath { // read the existing hosts b, err := ioutil.ReadFile(hostsBindMount) if err != nil { return err } if err := ioutil.WriteFile(hostsBindMount, append(b, []byte(c.cniHosts())...), 0644); err != nil { return err } } } // check if we have a bindmount for resolv.conf resolvBindMount := state.BindMounts["/etc/resolv.conf"] if len(outResolvConf) < 1 || resolvBindMount == "" || len(c.config.NetNsCtr) > 0 { return nil } // read the existing resolv.conf b, err := ioutil.ReadFile(resolvBindMount) if err != nil { return err } for _, line := range strings.Split(string(b), "\n") { // only keep things that don't start with nameserver from the old // resolv.conf file if !strings.HasPrefix(line, "nameserver") { outResolvConf = append([]string{line}, outResolvConf...) } } // write and return return ioutil.WriteFile(resolvBindMount, []byte(strings.Join(outResolvConf, "\n")), 0644) } func (c *Container) cniHosts() string { var hosts string if len(c.state.NetworkStatus) > 0 && len(c.state.NetworkStatus[0].IPs) > 0 { ipAddress := strings.Split(c.state.NetworkStatus[0].IPs[0].Address.String(), "/")[0] hosts += fmt.Sprintf("%s\t%s %s\n", ipAddress, c.Hostname(), c.Config().Name) } return hosts } // Initialize a container, creating it in the runtime func (c *Container) init(ctx context.Context, retainRetries bool) error { // Unconditionally remove conmon temporary files. // We've been running into far too many issues where they block startup. if err := c.removeConmonFiles(); err != nil { return err } // Generate the OCI newSpec newSpec, err := c.generateSpec(ctx) if err != nil { return err } // Save the OCI newSpec to disk if err := c.saveSpec(newSpec); err != nil { return err } for _, v := range c.config.NamedVolumes { if err := c.fixVolumePermissions(v); err != nil { return err } } // With the spec complete, do an OCI create if err := c.ociRuntime.CreateContainer(c, nil); err != nil { // Fedora 31 is carrying a patch to display improved error // messages to better handle the V2 transition. This is NOT // upstream in any OCI runtime. // TODO: Remove once runc supports cgroupsv2 if strings.Contains(err.Error(), "this version of runc doesn't work on cgroups v2") { logrus.Errorf("oci runtime %q does not support CGroups V2: use system migrate to mitigate", c.ociRuntime.Name()) } return err } logrus.Debugf("Created container %s in OCI runtime", c.ID()) // Remove any exec sessions leftover from a potential prior run. if len(c.state.ExecSessions) > 0 { if err := c.runtime.state.RemoveContainerExecSessions(c); err != nil { logrus.Errorf("Error removing container %s exec sessions from DB: %v", c.ID(), err) } c.state.ExecSessions = make(map[string]*ExecSession) } c.state.ExitCode = 0 c.state.Exited = false c.state.State = define.ContainerStateCreated c.state.StoppedByUser = false c.state.RestartPolicyMatch = false if !retainRetries { c.state.RestartCount = 0 } if err := c.save(); err != nil { return err } if c.config.HealthCheckConfig != nil { if err := c.createTimer(); err != nil { logrus.Error(err) } } defer c.newContainerEvent(events.Init) return c.completeNetworkSetup() } // Clean up a container in the OCI runtime. // Deletes the container in the runtime, and resets its state to Exited. // The container can be restarted cleanly after this. func (c *Container) cleanupRuntime(ctx context.Context) error { // If the container is not ContainerStateStopped or // ContainerStateCreated, do nothing. if !c.ensureState(define.ContainerStateStopped, define.ContainerStateCreated) { return nil } // If necessary, delete attach and ctl files if err := c.removeConmonFiles(); err != nil { return err } if err := c.delete(ctx); err != nil { return err } // If we were Stopped, we are now Exited, as we've removed ourself // from the runtime. // If we were Created, we are now Configured. if c.state.State == define.ContainerStateStopped { c.state.State = define.ContainerStateExited } else if c.state.State == define.ContainerStateCreated { c.state.State = define.ContainerStateConfigured } if c.valid { if err := c.save(); err != nil { return err } } logrus.Debugf("Successfully cleaned up container %s", c.ID()) return nil } // Reinitialize a container. // Deletes and recreates a container in the runtime. // Should only be done on ContainerStateStopped containers. // Not necessary for ContainerStateExited - the container has already been // removed from the runtime, so init() can proceed freely. func (c *Container) reinit(ctx context.Context, retainRetries bool) error { logrus.Debugf("Recreating container %s in OCI runtime", c.ID()) if err := c.cleanupRuntime(ctx); err != nil { return err } // Initialize the container again return c.init(ctx, retainRetries) } // Initialize (if necessary) and start a container // Performs all necessary steps to start a container that is not running // Does not lock or check validity func (c *Container) initAndStart(ctx context.Context) (retErr error) { // If we are ContainerStateUnknown, throw an error if c.state.State == define.ContainerStateUnknown { return errors.Wrapf(define.ErrCtrStateInvalid, "container %s is in an unknown state", c.ID()) } else if c.state.State == define.ContainerStateRemoving { return errors.Wrapf(define.ErrCtrStateInvalid, "cannot start container %s as it is being removed", c.ID()) } // If we are running, do nothing if c.state.State == define.ContainerStateRunning { return nil } // If we are paused, throw an error if c.state.State == define.ContainerStatePaused { return errors.Wrapf(define.ErrCtrStateInvalid, "cannot start paused container %s", c.ID()) } defer func() { if retErr != nil { if err := c.cleanup(ctx); err != nil { logrus.Errorf("error cleaning up container %s: %v", c.ID(), err) } } }() if err := c.prepare(); err != nil { return err } // If we are ContainerStateStopped we need to remove from runtime // And reset to ContainerStateConfigured if c.state.State == define.ContainerStateStopped { logrus.Debugf("Recreating container %s in OCI runtime", c.ID()) if err := c.reinit(ctx, false); err != nil { return err } } else if c.ensureState(define.ContainerStateConfigured, define.ContainerStateExited) { if err := c.init(ctx, false); err != nil { return err } } // Now start the container return c.start() } // Internal, non-locking function to start a container func (c *Container) start() error { if c.config.Spec.Process != nil { logrus.Debugf("Starting container %s with command %v", c.ID(), c.config.Spec.Process.Args) } if err := c.ociRuntime.StartContainer(c); err != nil { return err } logrus.Debugf("Started container %s", c.ID()) c.state.State = define.ContainerStateRunning if c.config.SdNotifyMode != define.SdNotifyModeIgnore { payload := fmt.Sprintf("MAINPID=%d", c.state.ConmonPID) if c.config.SdNotifyMode == define.SdNotifyModeConmon { payload += "\n" payload += daemon.SdNotifyReady } if sent, err := daemon.SdNotify(false, payload); err != nil { logrus.Errorf("Error notifying systemd of Conmon PID: %s", err.Error()) } else if sent { logrus.Debugf("Notify sent successfully") } } if c.config.HealthCheckConfig != nil { if err := c.updateHealthStatus(define.HealthCheckStarting); err != nil { logrus.Error(err) } if err := c.startTimer(); err != nil { logrus.Error(err) } } defer c.newContainerEvent(events.Start) return c.save() } // Internal, non-locking function to stop container func (c *Container) stop(timeout uint) error { logrus.Debugf("Stopping ctr %s (timeout %d)", c.ID(), timeout) // If the container is running in a PID Namespace, then killing the // primary pid is enough to kill the container. If it is not running in // a pid namespace then the OCI Runtime needs to kill ALL processes in // the containers cgroup in order to make sure the container is stopped. all := !c.hasNamespace(spec.PIDNamespace) // We can't use --all if CGroups aren't present. // Rootless containers with CGroups v1 and NoCgroups are both cases // where this can happen. if all { if c.config.NoCgroups { all = false } else if rootless.IsRootless() { // Only do this check if we need to unified, err := cgroups.IsCgroup2UnifiedMode() if err != nil { return err } if !unified { all = false } } } // Check if conmon is still alive. // If it is not, we won't be getting an exit file. conmonAlive, err := c.ociRuntime.CheckConmonRunning(c) if err != nil { return err } // Set the container state to "stopping" and unlock the container // before handing it over to conmon to unblock other commands. #8501 // demonstrates nicely that a high stop timeout will block even simple // commands such as `podman ps` from progressing if the container lock // is held when busy-waiting for the container to be stopped. c.state.State = define.ContainerStateStopping if err := c.save(); err != nil { return errors.Wrapf(err, "error saving container %s state before stopping", c.ID()) } if !c.batched { c.lock.Unlock() } stopErr := c.ociRuntime.StopContainer(c, timeout, all) if !c.batched { c.lock.Lock() if err := c.syncContainer(); err != nil { switch errors.Cause(err) { // If the container has already been removed (e.g., via // the cleanup process), there's nothing left to do. case define.ErrNoSuchCtr, define.ErrCtrRemoved: return stopErr default: if stopErr != nil { logrus.Errorf("Error syncing container %s status: %v", c.ID(), err) return stopErr } return err } } } // We have to check stopErr *after* we lock again - otherwise, we have a // change of panicking on a double-unlock. Ref: GH Issue 9615 if stopErr != nil { return stopErr } // Since we're now subject to a race condition with other processes who // may have altered the state (and other data), let's check if the // state has changed. If so, we should return immediately and log a // warning. if c.state.State != define.ContainerStateStopping { logrus.Warnf( "Container %q state changed from %q to %q while waiting for it to be stopped: discontinuing stop procedure as another process interfered", c.ID(), define.ContainerStateStopping, c.state.State, ) return nil } c.newContainerEvent(events.Stop) c.state.PID = 0 c.state.ConmonPID = 0 c.state.StoppedByUser = true if !conmonAlive { // Conmon is dead, so we can't expect an exit code. c.state.ExitCode = -1 c.state.FinishedTime = time.Now() c.state.State = define.ContainerStateStopped if err := c.save(); err != nil { logrus.Errorf("Error saving container %s status: %v", c.ID(), err) } return errors.Wrapf(define.ErrConmonDead, "container %s conmon process missing, cannot retrieve exit code", c.ID()) } if err := c.save(); err != nil { return errors.Wrapf(err, "error saving container %s state after stopping", c.ID()) } // Wait until we have an exit file, and sync once we do if err := c.waitForExitFileAndSync(); err != nil { return err } return nil } // Internal, non-locking function to pause a container func (c *Container) pause() error { if c.config.NoCgroups { return errors.Wrapf(define.ErrNoCgroups, "cannot pause without using CGroups") } if rootless.IsRootless() { cgroupv2, err := cgroups.IsCgroup2UnifiedMode() if err != nil { return errors.Wrap(err, "failed to determine cgroupversion") } if !cgroupv2 { return errors.Wrap(define.ErrNoCgroups, "can not pause containers on rootless containers with cgroup V1") } } if err := c.ociRuntime.PauseContainer(c); err != nil { // TODO when using docker-py there is some sort of race/incompatibility here return err } logrus.Debugf("Paused container %s", c.ID()) c.state.State = define.ContainerStatePaused return c.save() } // Internal, non-locking function to unpause a container func (c *Container) unpause() error { if c.config.NoCgroups { return errors.Wrapf(define.ErrNoCgroups, "cannot unpause without using CGroups") } if err := c.ociRuntime.UnpauseContainer(c); err != nil { // TODO when using docker-py there is some sort of race/incompatibility here return err } logrus.Debugf("Unpaused container %s", c.ID()) c.state.State = define.ContainerStateRunning return c.save() } // Internal, non-locking function to restart a container func (c *Container) restartWithTimeout(ctx context.Context, timeout uint) (retErr error) { if !c.ensureState(define.ContainerStateConfigured, define.ContainerStateCreated, define.ContainerStateRunning, define.ContainerStateStopped, define.ContainerStateExited) { return errors.Wrapf(define.ErrCtrStateInvalid, "unable to restart a container in a paused or unknown state") } c.newContainerEvent(events.Restart) if c.state.State == define.ContainerStateRunning { conmonPID := c.state.ConmonPID if err := c.stop(timeout); err != nil { return err } // Old versions of conmon have a bug where they create the exit file before // closing open file descriptors causing a race condition when restarting // containers with open ports since we cannot bind the ports as they're not // yet closed by conmon. // // Killing the old conmon PID is ~okay since it forces the FDs of old conmons // to be closed, while it's a NOP for newer versions which should have // exited already. if conmonPID != 0 { // Ignore errors from FindProcess() as conmon could already have exited. p, err := os.FindProcess(conmonPID) if p != nil && err == nil { if err = p.Kill(); err != nil { logrus.Debugf("error killing conmon process: %v", err) } } } // Ensure we tear down the container network so it will be // recreated - otherwise, behavior of restart differs from stop // and start if err := c.cleanupNetwork(); err != nil { return err } } defer func() { if retErr != nil { if err := c.cleanup(ctx); err != nil { logrus.Errorf("error cleaning up container %s: %v", c.ID(), err) } } }() if err := c.prepare(); err != nil { return err } if c.state.State == define.ContainerStateStopped { // Reinitialize the container if we need to if err := c.reinit(ctx, false); err != nil { return err } } else if c.state.State == define.ContainerStateConfigured || c.state.State == define.ContainerStateExited { // Initialize the container if err := c.init(ctx, false); err != nil { return err } } return c.start() } // mountStorage sets up the container's root filesystem // It mounts the image and any other requested mounts // TODO: Add ability to override mount label so we can use this for Mount() too // TODO: Can we use this for export? Copying SHM into the export might not be // good func (c *Container) mountStorage() (_ string, deferredErr error) { var err error // Container already mounted, nothing to do if c.state.Mounted { return c.state.Mountpoint, nil } mounted, err := mount.Mounted(c.config.ShmDir) if err != nil { return "", errors.Wrapf(err, "unable to determine if %q is mounted", c.config.ShmDir) } if !mounted && !MountExists(c.config.Spec.Mounts, "/dev/shm") { shmOptions := fmt.Sprintf("mode=1777,size=%d", c.config.ShmSize) if err := c.mountSHM(shmOptions); err != nil { return "", err } if err := os.Chown(c.config.ShmDir, c.RootUID(), c.RootGID()); err != nil { return "", errors.Wrapf(err, "failed to chown %s", c.config.ShmDir) } defer func() { if deferredErr != nil { if err := c.unmountSHM(c.config.ShmDir); err != nil { logrus.Errorf("Error unmounting SHM for container %s after mount error: %v", c.ID(), err) } } }() } // We need to mount the container before volumes - to ensure the copyup // works properly. mountPoint := c.config.Rootfs if mountPoint == "" { mountPoint, err = c.mount() if err != nil { return "", err } defer func() { if deferredErr != nil { if err := c.unmount(false); err != nil { logrus.Errorf("Error unmounting container %s after mount error: %v", c.ID(), err) } } }() } // If /etc/mtab does not exist in container image, then we need to // create it, so that mount command within the container will work. mtab := filepath.Join(mountPoint, "/etc/mtab") if err := idtools.MkdirAllAs(filepath.Dir(mtab), 0755, c.RootUID(), c.RootGID()); err != nil { return "", errors.Wrap(err, "error creating mtab directory") } if err = os.Symlink("/proc/mounts", mtab); err != nil && !os.IsExist(err) { return "", err } // Request a mount of all named volumes for _, v := range c.config.NamedVolumes { vol, err := c.mountNamedVolume(v, mountPoint) if err != nil { return "", err } defer func() { if deferredErr == nil { return } vol.lock.Lock() if err := vol.unmount(false); err != nil { logrus.Errorf("Error unmounting volume %s after error mounting container %s: %v", vol.Name(), c.ID(), err) } vol.lock.Unlock() }() } return mountPoint, nil } // Mount a single named volume into the container. // If necessary, copy up image contents into the volume. // Does not verify that the name volume given is actually present in container // config. // Returns the volume that was mounted. func (c *Container) mountNamedVolume(v *ContainerNamedVolume, mountpoint string) (*Volume, error) { logrus.Debugf("Going to mount named volume %s", v.Name) vol, err := c.runtime.state.Volume(v.Name) if err != nil { return nil, errors.Wrapf(err, "error retrieving named volume %s for container %s", v.Name, c.ID()) } if vol.config.LockID == c.config.LockID { return nil, errors.Wrapf(define.ErrWillDeadlock, "container %s and volume %s share lock ID %d", c.ID(), vol.Name(), c.config.LockID) } vol.lock.Lock() defer vol.lock.Unlock() if vol.needsMount() { if err := vol.mount(); err != nil { return nil, errors.Wrapf(err, "error mounting volume %s for container %s", vol.Name(), c.ID()) } } // The volume may need a copy-up. Check the state. if err := vol.update(); err != nil { return nil, err } if vol.state.NeedsCopyUp { logrus.Debugf("Copying up contents from container %s to volume %s", c.ID(), vol.Name()) // Set NeedsCopyUp to false immediately, so we don't try this // again when there are already files copied. vol.state.NeedsCopyUp = false if err := vol.save(); err != nil { return nil, err } // If the volume is not empty, we should not copy up. volMount := vol.mountPoint() contents, err := ioutil.ReadDir(volMount) if err != nil { return nil, errors.Wrapf(err, "error listing contents of volume %s mountpoint when copying up from container %s", vol.Name(), c.ID()) } if len(contents) > 0 { // The volume is not empty. It was likely modified // outside of Podman. For safety, let's not copy up into // it. Fixes CVE-2020-1726. return vol, nil } srcDir, err := securejoin.SecureJoin(mountpoint, v.Dest) if err != nil { return nil, errors.Wrapf(err, "error calculating destination path to copy up container %s volume %s", c.ID(), vol.Name()) } // Do a manual stat on the source directory to verify existence. // Skip the rest if it exists. // TODO: Should this be stat or lstat? I'm using lstat because I // think copy-up doesn't happen when the source is a link. srcStat, err := os.Lstat(srcDir) if err != nil { if os.IsNotExist(err) { // Source does not exist, don't bother copying // up. return vol, nil } return nil, errors.Wrapf(err, "error identifying source directory for copy up into volume %s", vol.Name()) } // If it's not a directory we're mounting over it. if !srcStat.IsDir() { return vol, nil } // Read contents, do not bother continuing if it's empty. Fixes // a bizarre issue where something copier.Get will ENOENT on // empty directories and sometimes it will not. // RHBZ#1928643 srcContents, err := ioutil.ReadDir(srcDir) if err != nil { return nil, errors.Wrapf(err, "error reading contents of source directory for copy up into volume %s", vol.Name()) } if len(srcContents) == 0 { return vol, nil } // Buildah Copier accepts a reader, so we'll need a pipe. reader, writer := io.Pipe() defer reader.Close() errChan := make(chan error, 1) logrus.Infof("About to copy up into volume %s", vol.Name()) // Copy, container side: get a tar archive of what needs to be // streamed into the volume. go func() { defer writer.Close() getOptions := copier.GetOptions{ KeepDirectoryNames: false, } errChan <- copier.Get(srcDir, "", getOptions, []string{"/."}, writer) }() // Copy, volume side: stream what we've written to the pipe, into // the volume. copyOpts := copier.PutOptions{} if err := copier.Put(volMount, "", copyOpts, reader); err != nil { err2 := <-errChan if err2 != nil { logrus.Errorf("Error streaming contents of container %s directory for volume copy-up: %v", c.ID(), err2) } return nil, errors.Wrapf(err, "error copying up to volume %s", vol.Name()) } if err := <-errChan; err != nil { return nil, errors.Wrapf(err, "error streaming container content for copy up into volume %s", vol.Name()) } } return vol, nil } // cleanupStorage unmounts and cleans up the container's root filesystem func (c *Container) cleanupStorage() error { if !c.state.Mounted { // Already unmounted, do nothing logrus.Debugf("Container %s storage is already unmounted, skipping...", c.ID()) return nil } var cleanupErr error for _, containerMount := range c.config.Mounts { if err := c.unmountSHM(containerMount); err != nil { if cleanupErr != nil { logrus.Errorf("Error unmounting container %s: %v", c.ID(), cleanupErr) } cleanupErr = err } } if err := c.cleanupOverlayMounts(); err != nil { // If the container can't remove content report the error logrus.Errorf("Failed to cleanup overlay mounts for %s: %v", c.ID(), err) cleanupErr = err } if c.config.Rootfs != "" { return cleanupErr } if err := c.unmount(false); err != nil { // If the container has already been removed, warn but don't // error // We still want to be able to kick the container out of the // state if errors.Cause(err) == storage.ErrNotAContainer || errors.Cause(err) == storage.ErrContainerUnknown || errors.Cause(err) == storage.ErrLayerNotMounted { logrus.Errorf("Storage for container %s has been removed", c.ID()) } else { if cleanupErr != nil { logrus.Errorf("Error cleaning up container %s storage: %v", c.ID(), cleanupErr) } cleanupErr = err } } // Request an unmount of all named volumes for _, v := range c.config.NamedVolumes { vol, err := c.runtime.state.Volume(v.Name) if err != nil { if cleanupErr != nil { logrus.Errorf("Error unmounting container %s: %v", c.ID(), cleanupErr) } cleanupErr = errors.Wrapf(err, "error retrieving named volume %s for container %s", v.Name, c.ID()) // We need to try and unmount every volume, so continue // if they fail. continue } if vol.needsMount() { vol.lock.Lock() if err := vol.unmount(false); err != nil { if cleanupErr != nil { logrus.Errorf("Error unmounting container %s: %v", c.ID(), cleanupErr) } cleanupErr = errors.Wrapf(err, "error unmounting volume %s for container %s", vol.Name(), c.ID()) } vol.lock.Unlock() } } c.state.Mountpoint = "" c.state.Mounted = false if c.valid { if err := c.save(); err != nil { if cleanupErr != nil { logrus.Errorf("Error unmounting container %s: %v", c.ID(), cleanupErr) } cleanupErr = err } } return cleanupErr } // Unmount the a container and free its resources func (c *Container) cleanup(ctx context.Context) error { var lastError error logrus.Debugf("Cleaning up container %s", c.ID()) // Remove healthcheck unit/timer file if it execs if c.config.HealthCheckConfig != nil { if err := c.removeTimer(); err != nil { logrus.Errorf("Error removing timer for container %s healthcheck: %v", c.ID(), err) } } // Clean up network namespace, if present if err := c.cleanupNetwork(); err != nil { lastError = errors.Wrapf(err, "error removing container %s network", c.ID()) } // Remove the container from the runtime, if necessary. // Do this *before* unmounting storage - some runtimes (e.g. Kata) // apparently object to having storage removed while the container still // exists. if err := c.cleanupRuntime(ctx); err != nil { if lastError != nil { logrus.Errorf("Error removing container %s from OCI runtime: %v", c.ID(), err) } else { lastError = err } } // Unmount storage if err := c.cleanupStorage(); err != nil { if lastError != nil { logrus.Errorf("Error unmounting container %s storage: %v", c.ID(), err) } else { lastError = errors.Wrapf(err, "error unmounting container %s storage", c.ID()) } } // Unmount image volumes for _, v := range c.config.ImageVolumes { img, _, err := c.runtime.LibimageRuntime().LookupImage(v.Source, nil) if err != nil { if lastError == nil { lastError = err continue } logrus.Errorf("error unmounting image volume %q:%q :%v", v.Source, v.Dest, err) } if err := img.Unmount(false); err != nil { if lastError == nil { lastError = err continue } logrus.Errorf("error unmounting image volume %q:%q :%v", v.Source, v.Dest, err) } } return lastError } // delete deletes the container and runs any configured poststop // hooks. func (c *Container) delete(ctx context.Context) error { if err := c.ociRuntime.DeleteContainer(c); err != nil { return errors.Wrapf(err, "error removing container %s from runtime", c.ID()) } if err := c.postDeleteHooks(ctx); err != nil { return errors.Wrapf(err, "container %s poststop hooks", c.ID()) } return nil } // postDeleteHooks runs the poststop hooks (if any) as specified by // the OCI Runtime Specification (which requires them to run // post-delete, despite the stage name). func (c *Container) postDeleteHooks(ctx context.Context) error { if c.state.ExtensionStageHooks != nil { extensionHooks, ok := c.state.ExtensionStageHooks["poststop"] if ok { state, err := json.Marshal(spec.State{ Version: spec.Version, ID: c.ID(), Status: "stopped", Bundle: c.bundlePath(), Annotations: c.config.Spec.Annotations, }) if err != nil { return err } for i, hook := range extensionHooks { hook := hook logrus.Debugf("container %s: invoke poststop hook %d, path %s", c.ID(), i, hook.Path) var stderr, stdout bytes.Buffer hookErr, err := exec.Run(ctx, &hook, state, &stdout, &stderr, exec.DefaultPostKillTimeout) if err != nil { logrus.Warnf("container %s: poststop hook %d: %v", c.ID(), i, err) if hookErr != err { logrus.Debugf("container %s: poststop hook %d (hook error): %v", c.ID(), i, hookErr) } stdoutString := stdout.String() if stdoutString != "" { logrus.Debugf("container %s: poststop hook %d: stdout:\n%s", c.ID(), i, stdoutString) } stderrString := stderr.String() if stderrString != "" { logrus.Debugf("container %s: poststop hook %d: stderr:\n%s", c.ID(), i, stderrString) } } } } } return nil } // writeStringToRundir writes the given string to a file with the given name in // the container's temporary files directory. The file will be chown'd to the // container's root user and have an appropriate SELinux label set. // If a file with the same name already exists, it will be deleted and recreated // with the new contents. // Returns the full path to the new file. func (c *Container) writeStringToRundir(destFile, contents string) (string, error) { destFileName := filepath.Join(c.state.RunDir, destFile) if err := os.Remove(destFileName); err != nil && !os.IsNotExist(err) { return "", errors.Wrapf(err, "error removing %s for container %s", destFile, c.ID()) } if err := writeStringToPath(destFileName, contents, c.config.MountLabel, c.RootUID(), c.RootGID()); err != nil { return "", err } return destFileName, nil } // writeStringToStaticDir writes the given string to a file with the given name // in the container's permanent files directory. The file will be chown'd to the // container's root user and have an appropriate SELinux label set. // Unlike writeStringToRundir, will *not* delete and re-create if the file // already exists (will instead error). // Returns the full path to the new file. func (c *Container) writeStringToStaticDir(filename, contents string) (string, error) { destFileName := filepath.Join(c.config.StaticDir, filename) if err := writeStringToPath(destFileName, contents, c.config.MountLabel, c.RootUID(), c.RootGID()); err != nil { return "", err } return destFileName, nil } // appendStringToRunDir appends the provided string to the runtimedir file func (c *Container) appendStringToRunDir(destFile, output string) (string, error) { destFileName := filepath.Join(c.state.RunDir, destFile) f, err := os.OpenFile(destFileName, os.O_APPEND|os.O_RDWR, 0600) if err != nil { return "", err } defer f.Close() compareStr := strings.TrimRight(output, "\n") scanner := bufio.NewScanner(f) scanner.Split(bufio.ScanLines) for scanner.Scan() { if strings.Compare(scanner.Text(), compareStr) == 0 { return filepath.Join(c.state.RunDir, destFile), nil } } if _, err := f.WriteString(output); err != nil { return "", errors.Wrapf(err, "unable to write %s", destFileName) } return filepath.Join(c.state.RunDir, destFile), nil } // saveSpec saves the OCI spec to disk, replacing any existing specs for the container func (c *Container) saveSpec(spec *spec.Spec) error { // If the OCI spec already exists, we need to replace it // Cannot guarantee some things, e.g. network namespaces, have the same // paths jsonPath := filepath.Join(c.bundlePath(), "config.json") if _, err := os.Stat(jsonPath); err != nil { if !os.IsNotExist(err) { return errors.Wrapf(err, "error doing stat on container %s spec", c.ID()) } // The spec does not exist, we're fine } else { // The spec exists, need to remove it if err := os.Remove(jsonPath); err != nil { return errors.Wrapf(err, "error replacing runtime spec for container %s", c.ID()) } } fileJSON, err := json.Marshal(spec) if err != nil { return errors.Wrapf(err, "error exporting runtime spec for container %s to JSON", c.ID()) } if err := ioutil.WriteFile(jsonPath, fileJSON, 0644); err != nil { return errors.Wrapf(err, "error writing runtime spec JSON for container %s to disk", c.ID()) } logrus.Debugf("Created OCI spec for container %s at %s", c.ID(), jsonPath) c.state.ConfigPath = jsonPath return nil } // Warning: precreate hooks may alter 'config' in place. func (c *Container) setupOCIHooks(ctx context.Context, config *spec.Spec) (map[string][]spec.Hook, error) { allHooks := make(map[string][]spec.Hook) if c.runtime.config.Engine.HooksDir == nil { if rootless.IsRootless() { return nil, nil } for _, hDir := range []string{hooks.DefaultDir, hooks.OverrideDir} { manager, err := hooks.New(ctx, []string{hDir}, []string{"precreate", "poststop"}) if err != nil { if os.IsNotExist(err) { continue } return nil, err } ociHooks, err := manager.Hooks(config, c.Spec().Annotations, len(c.config.UserVolumes) > 0) if err != nil { return nil, err } if len(ociHooks) > 0 || config.Hooks != nil { logrus.Warnf("implicit hook directories are deprecated; set --ociHooks-dir=%q explicitly to continue to load ociHooks from this directory", hDir) } for i, hook := range ociHooks { allHooks[i] = hook } } } else { manager, err := hooks.New(ctx, c.runtime.config.Engine.HooksDir, []string{"precreate", "poststop"}) if err != nil { return nil, err } allHooks, err = manager.Hooks(config, c.Spec().Annotations, len(c.config.UserVolumes) > 0) if err != nil { return nil, err } } hookErr, err := exec.RuntimeConfigFilter(ctx, allHooks["precreate"], config, exec.DefaultPostKillTimeout) if err != nil { logrus.Warnf("container %s: precreate hook: %v", c.ID(), err) if hookErr != nil && hookErr != err { logrus.Debugf("container %s: precreate hook (hook error): %v", c.ID(), hookErr) } return nil, err } return allHooks, nil } // mount mounts the container's root filesystem func (c *Container) mount() (string, error) { if c.state.State == define.ContainerStateRemoving { return "", errors.Wrapf(define.ErrCtrStateInvalid, "cannot mount container %s as it is being removed", c.ID()) } mountPoint, err := c.runtime.storageService.MountContainerImage(c.ID()) if err != nil { return "", errors.Wrapf(err, "error mounting storage for container %s", c.ID()) } mountPoint, err = filepath.EvalSymlinks(mountPoint) if err != nil { return "", errors.Wrapf(err, "error resolving storage path for container %s", c.ID()) } if err := os.Chown(mountPoint, c.RootUID(), c.RootGID()); err != nil { return "", errors.Wrapf(err, "cannot chown %s to %d:%d", mountPoint, c.RootUID(), c.RootGID()) } return mountPoint, nil } // unmount unmounts the container's root filesystem func (c *Container) unmount(force bool) error { // Also unmount storage if _, err := c.runtime.storageService.UnmountContainerImage(c.ID(), force); err != nil { return errors.Wrapf(err, "error unmounting container %s root filesystem", c.ID()) } return nil } // checkReadyForRemoval checks whether the given container is ready to be // removed. // These checks are only used if force-remove is not specified. // If it is, we'll remove the container anyways. // Returns nil if safe to remove, or an error describing why it's unsafe if not. func (c *Container) checkReadyForRemoval() error { if c.state.State == define.ContainerStateUnknown { return errors.Wrapf(define.ErrCtrStateInvalid, "container %s is in invalid state", c.ID()) } if c.ensureState(define.ContainerStateRunning, define.ContainerStatePaused) { return errors.Wrapf(define.ErrCtrStateInvalid, "cannot remove container %s as it is %s - running or paused containers cannot be removed without force", c.ID(), c.state.State.String()) } // Check exec sessions sessions, err := c.getActiveExecSessions() if err != nil { return err } if len(sessions) != 0 { return errors.Wrapf(define.ErrCtrStateInvalid, "cannot remove container %s as it has active exec sessions", c.ID()) } return nil } // canWithPrevious return the stat of the preCheckPoint dir func (c *Container) canWithPrevious() error { _, err := os.Stat(c.PreCheckPointPath()) return err } // prepareCheckpointExport writes the config and spec to // JSON files for later export func (c *Container) prepareCheckpointExport() error { // save live config if _, err := metadata.WriteJSONFile(c.Config(), c.bundlePath(), metadata.ConfigDumpFile); err != nil { return err } // save spec jsonPath := filepath.Join(c.bundlePath(), "config.json") g, err := generate.NewFromFile(jsonPath) if err != nil { logrus.Debugf("generating spec for container %q failed with %v", c.ID(), err) return err } if _, err := metadata.WriteJSONFile(g.Config, c.bundlePath(), metadata.SpecDumpFile); err != nil { return err } return nil } // sortUserVolumes sorts the volumes specified for a container // between named and normal volumes func (c *Container) sortUserVolumes(ctrSpec *spec.Spec) ([]*ContainerNamedVolume, []spec.Mount) { namedUserVolumes := []*ContainerNamedVolume{} userMounts := []spec.Mount{} // We need to parse all named volumes and mounts into maps, so we don't // end up with repeated lookups for each user volume. // Map destination to struct, as destination is what is stored in // UserVolumes. namedVolumes := make(map[string]*ContainerNamedVolume) mounts := make(map[string]spec.Mount) for _, namedVol := range c.config.NamedVolumes { namedVolumes[namedVol.Dest] = namedVol } for _, mount := range ctrSpec.Mounts { mounts[mount.Destination] = mount } for _, vol := range c.config.UserVolumes { if volume, ok := namedVolumes[vol]; ok { namedUserVolumes = append(namedUserVolumes, volume) } else if mount, ok := mounts[vol]; ok { userMounts = append(userMounts, mount) } else { logrus.Warnf("Could not find mount at destination %q when parsing user volumes for container %s", vol, c.ID()) } } return namedUserVolumes, userMounts } // Check for an exit file, and handle one if present func (c *Container) checkExitFile() error { // If the container's not running, nothing to do. if !c.ensureState(define.ContainerStateRunning, define.ContainerStatePaused, define.ContainerStateStopping) { return nil } exitFile, err := c.exitFilePath() if err != nil { return err } // Check for the exit file info, err := os.Stat(exitFile) if err != nil { if os.IsNotExist(err) { // Container is still running, no error return nil } return errors.Wrapf(err, "error running stat on container %s exit file", c.ID()) } // Alright, it exists. Transition to Stopped state. c.state.State = define.ContainerStateStopped c.state.PID = 0 c.state.ConmonPID = 0 // Read the exit file to get our stopped time and exit code. return c.handleExitFile(exitFile, info) } func (c *Container) hasNamespace(namespace spec.LinuxNamespaceType) bool { if c.config.Spec == nil || c.config.Spec.Linux == nil { return false } for _, n := range c.config.Spec.Linux.Namespaces { if n.Type == namespace { return true } } return false } // extractSecretToStorage copies a secret's data from the secrets manager to the container's static dir func (c *Container) extractSecretToCtrStorage(secr *ContainerSecret) error { manager, err := c.runtime.SecretsManager() if err != nil { return err } _, data, err := manager.LookupSecretData(secr.Name) if err != nil { return err } secretFile := filepath.Join(c.config.SecretsPath, secr.Name) hostUID, hostGID, err := butil.GetHostIDs(util.IDtoolsToRuntimeSpec(c.config.IDMappings.UIDMap), util.IDtoolsToRuntimeSpec(c.config.IDMappings.GIDMap), secr.UID, secr.GID) if err != nil { return errors.Wrap(err, "unable to extract secret") } err = ioutil.WriteFile(secretFile, data, 0644) if err != nil { return errors.Wrapf(err, "unable to create %s", secretFile) } if err := os.Lchown(secretFile, int(hostUID), int(hostGID)); err != nil { return err } if err := os.Chmod(secretFile, os.FileMode(secr.Mode)); err != nil { return err } if err := label.Relabel(secretFile, c.config.MountLabel, false); err != nil { return err } return nil }