package libpod import ( "bytes" "context" "fmt" "io" "io/ioutil" "os" "path/filepath" "strconv" "strings" "time" "github.com/containers/libpod/pkg/ctime" "github.com/containers/libpod/pkg/hooks" "github.com/containers/libpod/pkg/hooks/exec" "github.com/containers/libpod/pkg/rootless" "github.com/containers/storage" "github.com/containers/storage/pkg/archive" "github.com/containers/storage/pkg/mount" spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/opencontainers/selinux/go-selinux/label" opentracing "github.com/opentracing/opentracing-go" "github.com/pkg/errors" "github.com/sirupsen/logrus" "golang.org/x/text/language" kwait "k8s.io/apimachinery/pkg/util/wait" ) const ( // name of the directory holding the artifacts artifactsDir = "artifacts" ) var ( // localeToLanguage maps from locale values to language tags. localeToLanguage = map[string]string{ "": "und-u-va-posix", "c": "und-u-va-posix", "posix": "und-u-va-posix", } ) // 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 } 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 } // Get the size of the top layer by calculating the size of the diff // between the layer and its parent. The top layer of a container is // the only RW layer, all others are immutable layer, err := c.runtime.store.Layer(container.LayerID) if err != nil { return 0, err } return c.runtime.store.DiffSize(layer.Parent, layer.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(), "checkpoint") } // AttachSocketPath retrieves the path of the container's attach socket func (c *Container) AttachSocketPath() string { return filepath.Join(c.runtime.ociRuntime.socketsDir, c.ID(), "attach") } // Get PID file path for a container's exec session func (c *Container) execPidPath(sessionID string) string { return filepath.Join(c.state.RunDir, "exec_pid_"+sessionID) } // exitFilePath gets the path to the container's exit file func (c *Container) exitFilePath() string { return filepath.Join(c.runtime.ociRuntime.exitsDir, c.ID()) } // Wait for the container's exit file to appear. // When it does, update our state based on it. func (c *Container) waitForExitFileAndSync() error { exitFile := c.exitFilePath() err := kwait.ExponentialBackoff( kwait.Backoff{ Duration: 500 * time.Millisecond, Factor: 1.2, Steps: 6, }, func() (bool, error) { _, err := os.Stat(exitFile) if err != nil { // wait longer return false, nil } return true, nil }) if err != nil { // Exit file did not appear // Reset our state c.state.ExitCode = -1 c.state.FinishedTime = time.Now() c.state.State = ContainerStateStopped if err2 := c.save(); err2 != nil { logrus.Errorf("Error saving container %s state: %v", c.ID(), err2) } return err } if err := c.runtime.ociRuntime.updateContainerStatus(c, false); 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 return nil } // 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.state.State != ContainerStateUnknown) && (c.state.State != ContainerStateConfigured) && (c.state.State != ContainerStateExited) { oldState := c.state.State // TODO: optionally replace this with a stat for the exit file if err := c.runtime.ociRuntime.updateContainerStatus(c, false); err != nil { return err } // Only save back to DB if state changed if c.state.State != oldState { if err := c.save(); err != nil { return err } } } if !c.valid { return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID()) } return nil } // Create container root filesystem for use func (c *Container) setupStorage(ctx context.Context) error { span, _ := opentracing.StartSpanFromContext(ctx, "setupStorage") span.SetTag("type", "container") defer span.Finish() if !c.valid { return errors.Wrapf(ErrCtrRemoved, "container %s is not valid", c.ID()) } if c.state.State != ContainerStateConfigured { return errors.Wrapf(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(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.config.Privileged { privOpt := func(opt string) bool { for _, privopt := range []string{"nodev", "nosuid", "noexec"} { if opt == privopt { return true } } return false } defOptions, err := storage.GetDefaultMountOptions() 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 } if c.config.Rootfs == "" { 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") } if !rootless.IsRootless() && (len(c.config.IDMappings.UIDMap) != 0 || len(c.config.IDMappings.GIDMap) != 0) { info, err := os.Stat(c.runtime.config.TmpDir) if err != nil { return errors.Wrapf(err, "cannot stat `%s`", c.runtime.config.TmpDir) } if err := os.Chmod(c.runtime.config.TmpDir, info.Mode()|0111); err != nil { return errors.Wrapf(err, "cannot chmod `%s`", c.runtime.config.TmpDir) } root := filepath.Join(c.runtime.config.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 } c.state.UserNSRoot, err = filepath.EvalSymlinks(root) if err != nil { return errors.Wrapf(err, "failed to eval symlinks for %s", root) } } c.config.ProcessLabel = containerInfo.ProcessLabel c.config.MountLabel = containerInfo.MountLabel c.config.StaticDir = containerInfo.Dir c.state.RunDir = containerInfo.RunDir c.state.DestinationRunDir = c.state.RunDir if c.state.UserNSRoot != "" { c.state.DestinationRunDir = filepath.Join(c.state.UserNSRoot, "rundir") } // Set the default Entrypoint and Command if c.config.Entrypoint == nil { c.config.Entrypoint = containerInfo.Config.Config.Entrypoint } if c.config.Command == nil { c.config.Command = containerInfo.Config.Config.Cmd } artifacts := filepath.Join(c.config.StaticDir, artifactsDir) if err := os.MkdirAll(artifacts, 0755); err != nil { return errors.Wrapf(err, "error creating artifacts directory %q", artifacts) } return nil } // Tear down a container's storage prior to removal func (c *Container) teardownStorage() error { if c.state.State == ContainerStateRunning || c.state.State == ContainerStatePaused { return errors.Wrapf(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 artifacts %q", artifacts) } if err := c.cleanupStorage(); err != nil { return errors.Wrapf(err, "failed to cleanup container %s storage", c.ID()) } if c.state.UserNSRoot != "" { if err := os.RemoveAll(c.state.UserNSRoot); err != nil { return errors.Wrapf(err, "error removing userns root %q", c.state.UserNSRoot) } } 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 err == storage.ErrNotAContainer || err == storage.ErrContainerUnknown { logrus.Warnf("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) error { state.PID = 0 state.Mountpoint = "" state.Mounted = false if state.State != ContainerStateExited { state.State = ContainerStateConfigured } state.ExecSessions = make(map[string]*ExecSession) state.NetworkStatus = nil state.BindMounts = make(map[string]string) return nil } // 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(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()) } if len(c.config.IDMappings.UIDMap) != 0 || len(c.config.IDMappings.GIDMap) != 0 { info, err := os.Stat(c.runtime.config.TmpDir) if err != nil { return errors.Wrapf(err, "cannot stat `%s`", c.runtime.config.TmpDir) } if err := os.Chmod(c.runtime.config.TmpDir, info.Mode()|0111); err != nil { return errors.Wrapf(err, "cannot chmod `%s`", c.runtime.config.TmpDir) } root := filepath.Join(c.runtime.config.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 } c.state.UserNSRoot, err = filepath.EvalSymlinks(root) if err != nil { return errors.Wrapf(err, "failed to eval symlinks for %s", root) } } c.state.RunDir = dir c.state.DestinationRunDir = c.state.RunDir if c.state.UserNSRoot != "" { c.state.DestinationRunDir = filepath.Join(c.state.UserNSRoot, "rundir") } // We need to pick up a new lock lock, err := c.runtime.lockManager.RetrieveLock(c.config.LockID) if err != nil { return errors.Wrapf(err, "error acquiring lock for container %s", c.ID()) } c.lock = lock 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 } // 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 := filepath.Join(c.bundlePath(), "attach") 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()) } 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()) } // Instead of outright deleting the exit file, rename it (if it exists). // We want to retain it so we can get the exit code of containers which // are removed (at least until we have a workable events system) exitFile := filepath.Join(c.runtime.ociRuntime.exitsDir, c.ID()) oldExitFile := filepath.Join(c.runtime.ociRuntime.exitsDir, fmt.Sprintf("%s-old", c.ID())) if _, err := os.Stat(exitFile); err != nil { if !os.IsNotExist(err) { return errors.Wrapf(err, "error running stat on container %s exit file", c.ID()) } } else if err == nil { // Rename should replace the old exit file (if it exists) if err := os.Rename(exitFile, oldExitFile); err != nil { return errors.Wrapf(err, "error renaming container %s exit file", c.ID()) } } return nil } func (c *Container) export(path string) error { mountPoint := c.state.Mountpoint if !c.state.Mounted { mount, err := c.runtime.store.Mount(c.ID(), c.config.MountLabel) if err != nil { return errors.Wrapf(err, "error mounting container %q", c.ID()) } mountPoint = mount 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, error) { if !c.batched { c.lock.Lock() defer c.lock.Unlock() } err := c.syncContainer() if err != nil { return true, err } return (c.state.State != ContainerStateRunning && c.state.State != ContainerStatePaused), 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) (err error) { // Container must be created or stopped to be started if !(c.state.State == ContainerStateConfigured || c.state.State == ContainerStateCreated || c.state.State == ContainerStateStopped || c.state.State == ContainerStateExited) { return errors.Wrapf(ErrCtrStateInvalid, "container %s must be in Created or Stopped state to be started", c.ID()) } if !recursive { if err := c.checkDependenciesAndHandleError(ctx); err != nil { return err } } else { if err := c.startDependencies(ctx); err != nil { return err } } defer func() { if err != nil { if err2 := c.cleanup(ctx); err2 != nil { logrus.Errorf("error cleaning up container %s: %v", c.ID(), err2) } } }() if err := c.prepare(); err != nil { return err } if c.state.State == ContainerStateStopped { // Reinitialize the container if we need to if err := c.reinit(ctx); err != nil { return err } } else if c.state.State == ContainerStateConfigured || c.state.State == ContainerStateExited { // Or initialize it if necessary if err := c.init(ctx); err != nil { return err } } return nil } // checks dependencies are running and prints a helpful message func (c *Container) checkDependenciesAndHandleError(ctx context.Context) 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(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(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(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 visisted (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 propegate 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.LookupContainer(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 != 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 != ContainerStateRunning { notRunning = append(notRunning, dep) } depCtrs[dep] = depCtr } return notRunning, nil } // Check if a container's dependencies are running // Returns a []string containing the IDs of dependencies that are not running // Assumes depencies are already locked, and will be passed in // Accepts a map[string]*Container containing, at a minimum, the locked // dependency containers // (This must be a map from container ID to container) func (c *Container) checkDependenciesRunningLocked(depCtrs map[string]*Container) ([]string, error) { deps := c.Dependencies() notRunning := []string{} for _, dep := range deps { depCtr, ok := depCtrs[dep] if !ok { return nil, errors.Wrapf(ErrNoSuchCtr, "container %s depends on container %s but it is not on containers passed to checkDependenciesRunning", c.ID(), dep) } if err := c.syncContainer(); err != nil { return nil, err } if depCtr.state.State != ContainerStateRunning { notRunning = append(notRunning, dep) } } return notRunning, nil } func (c *Container) completeNetworkSetup() error { 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 == "slirp4netns" { return c.runtime.setupRootlessNetNS(c) } return c.runtime.setupNetNS(c) } // Initialize a container, creating it in the runtime func (c *Container) init(ctx context.Context) error { span, _ := opentracing.StartSpanFromContext(ctx, "init") span.SetTag("struct", "container") defer span.Finish() // Generate the OCI spec spec, err := c.generateSpec(ctx) if err != nil { return err } // Save the OCI spec to disk if err := c.saveSpec(spec); err != nil { return err } // With the spec complete, do an OCI create if err := c.runtime.ociRuntime.createContainer(c, c.config.CgroupParent, nil); err != nil { return err } logrus.Debugf("Created container %s in OCI runtime", c.ID()) c.state.ExitCode = 0 c.state.Exited = false c.state.State = ContainerStateCreated if err := c.save(); err != nil { return err } 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 { span, _ := opentracing.StartSpanFromContext(ctx, "cleanupRuntime") span.SetTag("struct", "container") defer span.Finish() // If the container is not ContainerStateStopped, do nothing if c.state.State != ContainerStateStopped { 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 } // Our state is now Exited, as we've removed ourself from // the runtime. c.state.State = ContainerStateExited 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) error { span, _ := opentracing.StartSpanFromContext(ctx, "reinit") span.SetTag("struct", "container") defer span.Finish() 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) } // 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) (err error) { // If we are ContainerStateUnknown, throw an error if c.state.State == ContainerStateUnknown { return errors.Wrapf(ErrCtrStateInvalid, "container %s is in an unknown state", c.ID()) } // If we are running, do nothing if c.state.State == ContainerStateRunning { return nil } // If we are paused, throw an error if c.state.State == ContainerStatePaused { return errors.Wrapf(ErrCtrStateInvalid, "cannot start paused container %s", c.ID()) } defer func() { if err != nil { if err2 := c.cleanup(ctx); err2 != nil { logrus.Errorf("error cleaning up container %s: %v", c.ID(), err2) } } }() 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 == ContainerStateStopped { logrus.Debugf("Recreating container %s in OCI runtime", c.ID()) if err := c.reinit(ctx); err != nil { return err } } else if c.state.State == ContainerStateConfigured || c.state.State == ContainerStateExited { if err := c.init(ctx); 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.runtime.ociRuntime.startContainer(c); err != nil { return err } logrus.Debugf("Started container %s", c.ID()) c.state.State = ContainerStateRunning return c.save() } // Internal, non-locking function to stop container func (c *Container) stop(timeout uint) error { logrus.Debugf("Stopping ctr %s with timeout %d", c.ID(), timeout) if err := c.runtime.ociRuntime.stopContainer(c, timeout); err != nil { return err } // Wait until we have an exit file, and sync once we do return c.waitForExitFileAndSync() } // Internal, non-locking function to pause a container func (c *Container) pause() error { if err := c.runtime.ociRuntime.pauseContainer(c); err != nil { return err } logrus.Debugf("Paused container %s", c.ID()) c.state.State = ContainerStatePaused return c.save() } // Internal, non-locking function to unpause a container func (c *Container) unpause() error { if err := c.runtime.ociRuntime.unpauseContainer(c); err != nil { return err } logrus.Debugf("Unpaused container %s", c.ID()) c.state.State = ContainerStateRunning return c.save() } // Internal, non-locking function to restart a container func (c *Container) restartWithTimeout(ctx context.Context, timeout uint) (err error) { if c.state.State == ContainerStateUnknown || c.state.State == ContainerStatePaused { return errors.Wrapf(ErrCtrStateInvalid, "unable to restart a container in a paused or unknown state") } if c.state.State == ContainerStateRunning { if err := c.stop(timeout); err != nil { return err } } defer func() { if err != nil { if err2 := c.cleanup(ctx); err2 != nil { logrus.Errorf("error cleaning up container %s: %v", c.ID(), err2) } } }() if err := c.prepare(); err != nil { return err } if c.state.State == ContainerStateStopped { // Reinitialize the container if we need to if err := c.reinit(ctx); err != nil { return err } } else if c.state.State == ContainerStateConfigured || c.state.State == ContainerStateExited { // Initialize the container if err := c.init(ctx); 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, 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) } } // TODO: generalize this mount code so it will mount every mount in ctr.config.Mounts mountPoint := c.config.Rootfs if mountPoint == "" { mountPoint, err = c.mount() if err != nil { return "", err } } return mountPoint, 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("Storage is already unmounted, skipping...") return nil } for _, mount := range c.config.Mounts { if err := c.unmountSHM(mount); err != nil { return err } } if c.config.Rootfs != "" { return nil } 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 err == storage.ErrNotAContainer || err == storage.ErrContainerUnknown { logrus.Errorf("Storage for container %s has been removed", c.ID()) return nil } return err } c.state.Mountpoint = "" c.state.Mounted = false if c.valid { return c.save() } return nil } // Unmount the a container and free its resources func (c *Container) cleanup(ctx context.Context) error { var lastError error span, _ := opentracing.StartSpanFromContext(ctx, "cleanup") span.SetTag("struct", "container") defer span.Finish() logrus.Debugf("Cleaning up container %s", c.ID()) // Clean up network namespace, if present if err := c.cleanupNetwork(); err != nil { 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 = err } } // Remove the container from the runtime, if necessary 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 } } return lastError } // delete deletes the container and runs any configured poststop // hooks. func (c *Container) delete(ctx context.Context) (err error) { span, _ := opentracing.StartSpanFromContext(ctx, "delete") span.SetTag("struct", "container") defer span.Finish() if err := c.runtime.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) (err error) { span, _ := opentracing.StartSpanFromContext(ctx, "postDeleteHooks") span.SetTag("struct", "container") defer span.Finish() 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 { 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 copies the provided file to the runtimedir func (c *Container) writeStringToRundir(destFile, output 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()) } f, err := os.Create(destFileName) if err != nil { return "", errors.Wrapf(err, "unable to create %s", destFileName) } defer f.Close() if err := f.Chown(c.RootUID(), c.RootGID()); err != nil { return "", err } if _, err := f.WriteString(output); err != nil { return "", errors.Wrapf(err, "unable to write %s", destFileName) } // Relabel runDirResolv for the container if err := label.Relabel(destFileName, c.config.MountLabel, false); err != nil { return "", err } return filepath.Join(c.state.DestinationRunDir, destFile), 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_WRONLY, 0600) if err != nil { return "", errors.Wrapf(err, "unable to open %s", destFileName) } defer f.Close() if _, err := f.WriteString(output); err != nil { return "", errors.Wrapf(err, "unable to write %s", destFileName) } return filepath.Join(c.state.DestinationRunDir, destFile), nil } // Save 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) (extensionStageHooks map[string][]spec.Hook, err error) { var locale string var ok bool for _, envVar := range []string{ "LC_ALL", "LC_COLLATE", "LANG", } { locale, ok = os.LookupEnv(envVar) if ok { break } } langString, ok := localeToLanguage[strings.ToLower(locale)] if !ok { langString = locale } lang, err := language.Parse(langString) if err != nil { logrus.Warnf("failed to parse language %q: %s", langString, err) lang, err = language.Parse("und-u-va-posix") if err != nil { return nil, err } } allHooks := make(map[string][]spec.Hook) if c.runtime.config.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"}, lang) if err != nil { if os.IsNotExist(err) { continue } return nil, err } hooks, err := manager.Hooks(config, c.Spec().Annotations, len(c.config.UserVolumes) > 0) if err != nil { return nil, err } if len(hooks) > 0 || config.Hooks != nil { logrus.Warnf("implicit hook directories are deprecated; set --hooks-dir=%q explicitly to continue to load hooks from this directory", hDir) } for i, hook := range hooks { allHooks[i] = hook } } } else { manager, err := hooks.New(ctx, c.runtime.config.HooksDir, []string{"precreate", "poststop"}, lang) if err != nil { if os.IsNotExist(err) { logrus.Warnf("Requested OCI hooks directory %q does not exist", c.runtime.config.HooksDir) return nil, 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) { 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()) } 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 } // getExcludedCGroups returns a string slice of cgroups we want to exclude // because runc or other components are unaware of them. func getExcludedCGroups() (excludes []string) { excludes = []string{"rdma"} return } // namedVolumes returns named volumes for the container func (c *Container) namedVolumes() ([]string, error) { var volumes []string for _, vol := range c.config.Spec.Mounts { if strings.HasPrefix(vol.Source, c.runtime.config.VolumePath) { volume := strings.TrimPrefix(vol.Source, c.runtime.config.VolumePath+"/") split := strings.Split(volume, "/") volume = split[0] if _, err := c.runtime.state.Volume(volume); err == nil { volumes = append(volumes, volume) } } } return volumes, nil } // this should be from chrootarchive. func (c *Container) copyWithTarFromImage(src, dest string) error { mountpoint, err := c.mount() if err != nil { return err } a := archive.NewDefaultArchiver() source := filepath.Join(mountpoint, src) return a.CopyWithTar(source, dest) }