package libpod import ( "context" "io" "io/ioutil" "net/http" "os" "sync" "time" "github.com/containers/podman/v3/libpod/define" "github.com/containers/podman/v3/libpod/events" "github.com/containers/podman/v3/pkg/signal" "github.com/containers/storage/pkg/archive" "github.com/pkg/errors" "github.com/sirupsen/logrus" ) // Init creates a container in the OCI runtime, moving a container from // ContainerStateConfigured, ContainerStateStopped, or ContainerStateExited to // ContainerStateCreated. Once in Created state, Conmon will be running, which // allows the container to be attached to. The container can subsequently // transition to ContainerStateRunning via Start(), or be transitioned back to // ContainerStateConfigured by Cleanup() (which will stop conmon and unmount the // container). // Init requires that all dependency containers be started (e.g. pod infra // containers). The `recursive` parameter will, if set to true, start these // dependency containers before initializing this container. func (c *Container) Init(ctx context.Context, recursive bool) error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if !c.ensureState(define.ContainerStateConfigured, define.ContainerStateStopped, define.ContainerStateExited) { return errors.Wrapf(define.ErrCtrStateInvalid, "container %s has already been created in runtime", c.ID()) } if !recursive { if err := c.checkDependenciesAndHandleError(); err != nil { return err } } else { if err := c.startDependencies(ctx); err != nil { return err } } if err := c.prepare(); err != nil { if err2 := c.cleanup(ctx); err2 != nil { logrus.Errorf("error cleaning up container %s: %v", c.ID(), err2) } return err } if c.state.State == define.ContainerStateStopped { // Reinitialize the container return c.reinit(ctx, false) } // Initialize the container for the first time return c.init(ctx, false) } // Start starts the given container. // Start will accept container in ContainerStateConfigured, // ContainerStateCreated, ContainerStateStopped, and ContainerStateExited, and // transition them to ContainerStateRunning (all containers not in // ContainerStateCreated will make an intermediate stop there via the Init API). // Once in ContainerStateRunning, the container can be transitioned to // ContainerStatePaused via Pause(), or to ContainerStateStopped by the process // stopping (either due to exit, or being forced to stop by the Kill or Stop API // calls). // Start requites that all dependency containers (e.g. pod infra containers) be // running before being run. The recursive parameter, if set, will start all // dependencies before starting this container. func (c *Container) Start(ctx context.Context, recursive bool) error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if err := c.prepareToStart(ctx, recursive); err != nil { return err } // Start the container return c.start() } // StartAndAttach starts a container and attaches to it. // This acts as a combination of the Start and Attach APIs, ensuring proper // ordering of the two such that no output from the container is lost (e.g. the // Attach call occurs before Start). // In overall functionality, it is identical to the Start call, with the added // side effect that an attach session will also be started. func (c *Container) StartAndAttach(ctx context.Context, streams *define.AttachStreams, keys string, resize <-chan define.TerminalSize, recursive bool) (<-chan error, error) { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return nil, err } } if err := c.prepareToStart(ctx, recursive); err != nil { return nil, err } attachChan := make(chan error) // We need to ensure that we don't return until start() fired in attach. // Use a channel to sync startedChan := make(chan bool) // Attach to the container before starting it go func() { if err := c.attach(streams, keys, resize, true, startedChan, nil); err != nil { attachChan <- err } close(attachChan) }() select { case err := <-attachChan: return nil, err case <-startedChan: c.newContainerEvent(events.Attach) } return attachChan, nil } // RestartWithTimeout restarts a running container and takes a given timeout in uint func (c *Container) RestartWithTimeout(ctx context.Context, timeout uint) error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if err := c.checkDependenciesAndHandleError(); err != nil { return err } return c.restartWithTimeout(ctx, timeout) } // Stop uses the container's stop signal (or SIGTERM if no signal was specified) // to stop the container, and if it has not stopped after container's stop // timeout, SIGKILL is used to attempt to forcibly stop the container // Default stop timeout is 10 seconds, but can be overridden when the container // is created func (c *Container) Stop() error { // Stop with the container's given timeout return c.StopWithTimeout(c.config.StopTimeout) } // StopWithTimeout is a version of Stop that allows a timeout to be specified // manually. If timeout is 0, SIGKILL will be used immediately to kill the // container. func (c *Container) StopWithTimeout(timeout uint) error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if c.ensureState(define.ContainerStateStopped, define.ContainerStateExited) { return define.ErrCtrStopped } if !c.ensureState(define.ContainerStateCreated, define.ContainerStateRunning) { return errors.Wrapf(define.ErrCtrStateInvalid, "can only stop created or running containers. %s is in state %s", c.ID(), c.state.State.String()) } return c.stop(timeout) } // Kill sends a signal to a container func (c *Container) Kill(signal uint) error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } // TODO: Is killing a paused container OK? switch c.state.State { case define.ContainerStateRunning, define.ContainerStateStopping: // Note that killing containers in "stopping" state is okay. // In that state, the Podman is waiting for the runtime to // stop the container and if that is taking too long, a user // may have decided to kill the container after all. default: return errors.Wrapf(define.ErrCtrStateInvalid, "can only kill running containers. %s is in state %s", c.ID(), c.state.State.String()) } // Hardcode all = false, we only use all when removing. if err := c.ociRuntime.KillContainer(c, signal, false); err != nil { return err } c.state.StoppedByUser = true c.newContainerEvent(events.Kill) return c.save() } // Attach attaches to a container. // This function returns when the attach finishes. It does not hold the lock for // the duration of its runtime, only using it at the beginning to verify state. func (c *Container) Attach(streams *define.AttachStreams, keys string, resize <-chan define.TerminalSize) error { if !c.batched { c.lock.Lock() if err := c.syncContainer(); err != nil { c.lock.Unlock() return err } // We are NOT holding the lock for the duration of the function. c.lock.Unlock() } if !c.ensureState(define.ContainerStateCreated, define.ContainerStateRunning) { return errors.Wrapf(define.ErrCtrStateInvalid, "can only attach to created or running containers") } // HACK: This is really gross, but there isn't a better way without // splitting attach into separate versions for StartAndAttach and normal // attaching, and I really do not want to do that right now. // Send a SIGWINCH after attach succeeds so that most programs will // redraw the screen for the new attach session. attachRdy := make(chan bool, 1) if c.config.Spec.Process != nil && c.config.Spec.Process.Terminal { go func() { <-attachRdy if err := c.ociRuntime.KillContainer(c, uint(signal.SIGWINCH), false); err != nil { logrus.Warnf("Unable to send SIGWINCH to container %s after attach: %v", c.ID(), err) } }() } c.newContainerEvent(events.Attach) return c.attach(streams, keys, resize, false, nil, attachRdy) } // HTTPAttach forwards an attach session over a hijacked HTTP session. // HTTPAttach will consume and close the included httpCon, which is expected to // be sourced from a hijacked HTTP connection. // The cancel channel is optional, and can be used to asynchronously cancel the // attach session. // The streams variable is only supported if the container was not a terminal, // and allows specifying which of the container's standard streams will be // forwarded to the client. // This function returns when the attach finishes. It does not hold the lock for // the duration of its runtime, only using it at the beginning to verify state. // The streamLogs parameter indicates that all the container's logs until present // will be streamed at the beginning of the attach. // The streamAttach parameter indicates that the attach itself will be streamed // over the socket; if this is not set, but streamLogs is, only the logs will be // sent. // At least one of streamAttach and streamLogs must be set. func (c *Container) HTTPAttach(r *http.Request, w http.ResponseWriter, streams *HTTPAttachStreams, detachKeys *string, cancel <-chan bool, streamAttach, streamLogs bool, hijackDone chan<- bool) error { // Ensure we don't leak a goroutine if we exit before hijack completes. defer func() { close(hijackDone) }() if !c.batched { c.lock.Lock() if err := c.syncContainer(); err != nil { c.lock.Unlock() return err } // We are NOT holding the lock for the duration of the function. c.lock.Unlock() } if !c.ensureState(define.ContainerStateCreated, define.ContainerStateRunning) { return errors.Wrapf(define.ErrCtrStateInvalid, "can only attach to created or running containers") } if !streamAttach && !streamLogs { return errors.Wrapf(define.ErrInvalidArg, "must specify at least one of stream or logs") } logrus.Infof("Performing HTTP Hijack attach to container %s", c.ID()) c.newContainerEvent(events.Attach) return c.ociRuntime.HTTPAttach(c, r, w, streams, detachKeys, cancel, hijackDone, streamAttach, streamLogs) } // AttachResize resizes the container's terminal, which is displayed by Attach // and HTTPAttach. func (c *Container) AttachResize(newSize define.TerminalSize) error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if !c.ensureState(define.ContainerStateCreated, define.ContainerStateRunning) { return errors.Wrapf(define.ErrCtrStateInvalid, "can only resize created or running containers") } logrus.Infof("Resizing TTY of container %s", c.ID()) return c.ociRuntime.AttachResize(c, newSize) } // Mount mounts a container's filesystem on the host // The path where the container has been mounted is returned func (c *Container) Mount() (string, error) { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return "", err } } defer c.newContainerEvent(events.Mount) return c.mount() } // Unmount unmounts a container's filesystem on the host func (c *Container) Unmount(force bool) error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if c.state.Mounted { mounted, err := c.runtime.storageService.MountedContainerImage(c.ID()) if err != nil { return errors.Wrapf(err, "can't determine how many times %s is mounted, refusing to unmount", c.ID()) } if mounted == 1 { if c.ensureState(define.ContainerStateRunning, define.ContainerStatePaused) { return errors.Wrapf(define.ErrCtrStateInvalid, "cannot unmount storage for container %s as it is running or paused", c.ID()) } execSessions, err := c.getActiveExecSessions() if err != nil { return err } if len(execSessions) != 0 { return errors.Wrapf(define.ErrCtrStateInvalid, "container %s has active exec sessions, refusing to unmount", c.ID()) } return errors.Wrapf(define.ErrInternal, "can't unmount %s last mount, it is still in use", c.ID()) } } defer c.newContainerEvent(events.Unmount) return c.unmount(force) } // Pause pauses a container func (c *Container) Pause() error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if c.state.State == define.ContainerStatePaused { return errors.Wrapf(define.ErrCtrStateInvalid, "%q is already paused", c.ID()) } if c.state.State != define.ContainerStateRunning { return errors.Wrapf(define.ErrCtrStateInvalid, "%q is not running, can't pause", c.state.State) } defer c.newContainerEvent(events.Pause) return c.pause() } // Unpause unpauses a container func (c *Container) Unpause() error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if c.state.State != define.ContainerStatePaused { return errors.Wrapf(define.ErrCtrStateInvalid, "%q is not paused, can't unpause", c.ID()) } defer c.newContainerEvent(events.Unpause) return c.unpause() } // Export exports a container's root filesystem as a tar archive // The archive will be saved as a file at the given path func (c *Container) Export(path string) error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if c.state.State == define.ContainerStateRemoving { return errors.Wrapf(define.ErrCtrStateInvalid, "cannot mount container %s as it is being removed", c.ID()) } defer c.newContainerEvent(events.Mount) return c.export(path) } // AddArtifact creates and writes to an artifact file for the container func (c *Container) AddArtifact(name string, data []byte) error { if !c.valid { return define.ErrCtrRemoved } return ioutil.WriteFile(c.getArtifactPath(name), data, 0740) } // GetArtifact reads the specified artifact file from the container func (c *Container) GetArtifact(name string) ([]byte, error) { if !c.valid { return nil, define.ErrCtrRemoved } return ioutil.ReadFile(c.getArtifactPath(name)) } // RemoveArtifact deletes the specified artifacts file func (c *Container) RemoveArtifact(name string) error { if !c.valid { return define.ErrCtrRemoved } return os.Remove(c.getArtifactPath(name)) } // Wait blocks until the container exits and returns its exit code. func (c *Container) Wait(ctx context.Context) (int32, error) { return c.WaitWithInterval(ctx, DefaultWaitInterval) } // WaitWithInterval blocks until the container to exit and returns its exit // code. The argument is the interval at which checks the container's status. func (c *Container) WaitWithInterval(ctx context.Context, waitTimeout time.Duration) (int32, error) { if !c.valid { return -1, define.ErrCtrRemoved } exitFile, err := c.exitFilePath() if err != nil { return -1, err } chWait := make(chan error, 1) go func() { <-ctx.Done() chWait <- define.ErrCanceled }() for { // ignore errors here (with exception of cancellation), it is only used to avoid waiting // too long. _, e := WaitForFile(exitFile, chWait, waitTimeout) if e == define.ErrCanceled { return -1, define.ErrCanceled } stopped, code, err := c.isStopped() if err != nil { return -1, err } if stopped { return code, nil } } } type waitResult struct { code int32 err error } func (c *Container) WaitForConditionWithInterval(ctx context.Context, waitTimeout time.Duration, conditions ...define.ContainerStatus) (int32, error) { if !c.valid { return -1, define.ErrCtrRemoved } if len(conditions) == 0 { panic("at least one condition should be passed") } ctx, cancelFn := context.WithCancel(ctx) defer cancelFn() resultChan := make(chan waitResult) waitForExit := false wantedStates := make(map[define.ContainerStatus]bool, len(conditions)) for _, condition := range conditions { if condition == define.ContainerStateStopped || condition == define.ContainerStateExited { waitForExit = true continue } wantedStates[condition] = true } trySend := func(code int32, err error) { select { case resultChan <- waitResult{code, err}: case <-ctx.Done(): } } var wg sync.WaitGroup if waitForExit { wg.Add(1) go func() { defer wg.Done() code, err := c.WaitWithInterval(ctx, waitTimeout) trySend(code, err) }() } if len(wantedStates) > 0 { wg.Add(1) go func() { defer wg.Done() for { state, err := c.State() if err != nil { trySend(-1, err) return } if _, found := wantedStates[state]; found { trySend(-1, nil) return } select { case <-ctx.Done(): return case <-time.After(waitTimeout): continue } } }() } var result waitResult select { case result = <-resultChan: cancelFn() case <-ctx.Done(): result = waitResult{-1, define.ErrCanceled} } wg.Wait() return result.code, result.err } // Cleanup unmounts all mount points in container and cleans up container storage // It also cleans up the network stack func (c *Container) Cleanup(ctx context.Context) error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } // Check if state is good if !c.ensureState(define.ContainerStateConfigured, define.ContainerStateCreated, define.ContainerStateStopped, define.ContainerStateStopping, define.ContainerStateExited) { return errors.Wrapf(define.ErrCtrStateInvalid, "container %s is running or paused, refusing to clean up", c.ID()) } // Handle restart policy. // Returns a bool indicating whether we actually restarted. // If we did, don't proceed to cleanup - just exit. didRestart, err := c.handleRestartPolicy(ctx) if err != nil { return err } if didRestart { return nil } // If we didn't restart, we perform a normal cleanup // Check for running exec sessions sessions, err := c.getActiveExecSessions() if err != nil { return err } if len(sessions) > 0 { return errors.Wrapf(define.ErrCtrStateInvalid, "container %s has active exec sessions, refusing to clean up", c.ID()) } defer c.newContainerEvent(events.Cleanup) return c.cleanup(ctx) } // Batch starts a batch operation on the given container // All commands in the passed function will execute under the same lock and // without synchronizing state after each operation // This will result in substantial performance benefits when running numerous // commands on the same container // Note that the container passed into the Batch function cannot be removed // during batched operations. runtime.RemoveContainer can only be called outside // of Batch // Any error returned by the given batch function will be returned unmodified by // Batch // As Batch normally disables updating the current state of the container, the // Sync() function is provided to enable container state to be updated and // checked within Batch. func (c *Container) Batch(batchFunc func(*Container) error) error { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } newCtr := new(Container) newCtr.config = c.config newCtr.state = c.state newCtr.runtime = c.runtime newCtr.ociRuntime = c.ociRuntime newCtr.lock = c.lock newCtr.valid = true newCtr.batched = true err := batchFunc(newCtr) newCtr.batched = false return err } // Sync updates the status of a container by querying the OCI runtime. // If the container has not been created inside the OCI runtime, nothing will be // done. // Most of the time, Podman does not explicitly query the OCI runtime for // container status, and instead relies upon exit files created by conmon. // This can cause a disconnect between running state and what Podman sees in // cases where Conmon was killed unexpected, or runc was upgraded. // Running a manual Sync() ensures that container state will be correct in // such situations. func (c *Container) Sync() error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() } // 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.ContainerStatePaused, define.ContainerStateStopped) { oldState := c.state.State if err := c.ociRuntime.UpdateContainerStatus(c); 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 } } } defer c.newContainerEvent(events.Sync) return nil } // ReloadNetwork reconfigures the container's network. // Technically speaking, it will tear down and then reconfigure the container's // network namespace, which will result in all firewall rules being recreated. // It is mostly intended to be used in cases where the system firewall has been // reloaded, and existing rules have been wiped out. It is expected that some // downtime will result, as the rules are destroyed as part of this process. // At present, this only works on root containers; it may be expanded to restart // slirp4netns in the future to work with rootless containers as well. // Requires that the container must be running or created. func (c *Container) ReloadNetwork() error { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } if !c.ensureState(define.ContainerStateCreated, define.ContainerStateRunning) { return errors.Wrapf(define.ErrCtrStateInvalid, "cannot reload network unless container network has been configured") } return c.reloadNetwork() } // Refresh is DEPRECATED and REMOVED. func (c *Container) Refresh(ctx context.Context) error { // This has been deprecated for a long while, and is in the process of // being removed. return define.ErrNotImplemented } // ContainerCheckpointOptions is a struct used to pass the parameters // for checkpointing (and restoring) to the corresponding functions type ContainerCheckpointOptions struct { // Keep tells the API to not delete checkpoint artifacts Keep bool // KeepRunning tells the API to keep the container running // after writing the checkpoint to disk KeepRunning bool // TCPEstablished tells the API to checkpoint a container // even if it contains established TCP connections TCPEstablished bool // TargetFile tells the API to read (or write) the checkpoint image // from (or to) the filename set in TargetFile TargetFile string // Name tells the API that during restore from an exported // checkpoint archive a new name should be used for the // restored container Name string // IgnoreRootfs tells the API to not export changes to // the container's root file-system (or to not import) IgnoreRootfs bool // IgnoreStaticIP tells the API to ignore the IP set // during 'podman run' with '--ip'. This is especially // important to be able to restore a container multiple // times with '--import --name'. IgnoreStaticIP bool // IgnoreStaticMAC tells the API to ignore the MAC set // during 'podman run' with '--mac-address'. This is especially // important to be able to restore a container multiple // times with '--import --name'. IgnoreStaticMAC bool // IgnoreVolumes tells the API to not export or not to import // the content of volumes associated with the container IgnoreVolumes bool // Pre Checkpoint container and leave container running PreCheckPoint bool // Dump container with Pre Checkpoint images WithPrevious bool // ImportPrevious tells the API to restore container with two // images. One is TargetFile, the other is ImportPrevious. ImportPrevious string // Compression tells the API which compression to use for // the exported checkpoint archive. Compression archive.Compression } // Checkpoint checkpoints a container func (c *Container) Checkpoint(ctx context.Context, options ContainerCheckpointOptions) error { logrus.Debugf("Trying to checkpoint container %s", c.ID()) if options.TargetFile != "" { if err := c.prepareCheckpointExport(); err != nil { return err } } if options.WithPrevious { if err := c.canWithPrevious(); err != nil { return err } } if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } return c.checkpoint(ctx, options) } // Restore restores a container func (c *Container) Restore(ctx context.Context, options ContainerCheckpointOptions) error { logrus.Debugf("Trying to restore container %s", c.ID()) if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return err } } defer c.newContainerEvent(events.Restore) return c.restore(ctx, options) } // Indicate whether or not the container should restart func (c *Container) ShouldRestart(ctx context.Context) bool { logrus.Debugf("Checking if container %s should restart", c.ID()) if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return false } } return c.shouldRestart() } // CopyFromArchive copies the contents from the specified tarStream to path // *inside* the container. func (c *Container) CopyFromArchive(ctx context.Context, containerPath string, chown bool, rename map[string]string, tarStream io.Reader) (func() error, error) { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return nil, err } } return c.copyFromArchive(ctx, containerPath, chown, rename, tarStream) } // CopyToArchive copies the contents from the specified path *inside* the // container to the tarStream. func (c *Container) CopyToArchive(ctx context.Context, containerPath string, tarStream io.Writer) (func() error, error) { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return nil, err } } return c.copyToArchive(ctx, containerPath, tarStream) } // Stat the specified path *inside* the container and return a file info. func (c *Container) Stat(ctx context.Context, containerPath string) (*define.FileInfo, error) { if !c.batched { c.lock.Lock() defer c.lock.Unlock() if err := c.syncContainer(); err != nil { return nil, err } } var mountPoint string var err error if c.state.Mounted { mountPoint = c.state.Mountpoint } else { mountPoint, err = c.mount() if err != nil { return nil, err } defer c.unmount(false) } info, _, _, err := c.stat(ctx, mountPoint, containerPath) return info, err }