diff options
| -rw-r--r-- | libpod/container_api.go | 84 | ||||
| -rw-r--r-- | libpod/container_inspect.go | 7 | ||||
| -rw-r--r-- | libpod/container_internal.go | 5 | ||||
| -rw-r--r-- | libpod/oci.go | 18 | ||||
| -rw-r--r-- | libpod/util.go | 29 |
5 files changed, 135 insertions, 8 deletions
diff --git a/libpod/container_api.go b/libpod/container_api.go index b7e523d7a..c1c1689df 100644 --- a/libpod/container_api.go +++ b/libpod/container_api.go @@ -5,8 +5,11 @@ import ( "io/ioutil" "os" "path/filepath" + "strconv" + "time" "github.com/docker/docker/daemon/caps" + "github.com/docker/docker/pkg/stringid" "github.com/docker/docker/pkg/term" "github.com/pkg/errors" "github.com/projectatomic/libpod/libpod/driver" @@ -235,7 +238,86 @@ func (c *Container) Exec(tty, privileged bool, env, cmd []string, user string) e capList = caps.GetAllCapabilities() } - return c.runtime.ociRuntime.execContainer(c, cmd, tty, user, capList, env) + // Generate exec session ID + // Ensure we don't conflict with an existing session ID + sessionID := stringid.GenerateNonCryptoID() + found := true + // This really ought to be a do-while, but Go doesn't have those... + for found { + found = false + for id, _ := range c.state.ExecSessions { + if id == sessionID { + found = true + break + } + } + if found == true { + sessionID = stringid.GenerateNonCryptoID() + } + } + + execCmd, err := c.runtime.ociRuntime.execContainer(c, cmd, capList, env, tty, user, sessionID) + if err != nil { + return errors.Wrapf(err, "error creating exec command for container %s", c.ID()) + } + + if err := execCmd.Start(); err != nil { + return errors.Wrapf(err, "error starting exec command for container %s", c.ID()) + } + + pidFile := c.execPidPath(sessionID) + const pidWaitTimeout = 250 + + // Wait until runc makes the pidfile + // TODO: If runc errors before the PID file is created, we have to wait for timeout here + if err := WaitForFile(pidFile, pidWaitTimeout * time.Millisecond); err != nil { + logrus.Debugf("Timed out waiting for pidfile from runc for container %s exec", c.ID()) + + // Check if an error occurred in the process before we made a pidfile + // TODO: Wait() here is a poor choice - is there a way to see if + // a process has finished, instead of waiting for it to finish? + if err := execCmd.Wait(); err != nil { + return err + } + + return errors.Wrapf(err, "timed out waiting for runc to create pidfile for exec session in container %s", c.ID()) + } + + // Pidfile exists, read it + contents, err := ioutil.ReadFile(pidFile) + if err != nil { + // We don't know the PID of the exec session + // However, it may still be alive + // TODO handle this better + return errors.Wrapf(err, "could not read pidfile for exec session %s in container %s", sessionID, c.ID()) + } + pid, err := strconv.ParseInt(string(contents), 10, 32) + if err != nil { + // As above, we don't have a valid PID, but the exec session is likely still alive + // TODO handle this better + return errors.Wrapf(err, "error parsing PID of exec session %s in container %s", sessionID, c.ID()) + } + + // We have the PID, add it to state + if c.state.ExecSessions == nil { + c.state.ExecSessions = make(map[string]int) + } + c.state.ExecSessions[sessionID] = int(pid) + if err := c.save(); err != nil { + // Now we have a PID but we can't save it in the DB + // TODO handle this better + return errors.Wrapf(err, "error saving exec sessions %s for container %s", sessionID, c.ID()) + } + + waitErr := execCmd.Wait() + + // Remove the exec session from state + delete(c.state.ExecSessions, sessionID) + if err := c.save(); err != nil { + logrus.Errorf("Error removing exec session %s from container %s state: %v", sessionID, c.ID(), err) + } + + return waitErr } // Attach attaches to a container diff --git a/libpod/container_inspect.go b/libpod/container_inspect.go index 124126708..de5770f8f 100644 --- a/libpod/container_inspect.go +++ b/libpod/container_inspect.go @@ -20,6 +20,11 @@ func (c *Container) getContainerInspectData(size bool, driverData *inspect.Data) args = args[1:] } + execIDs := []string{} + for id, _ := range c.state.ExecSessions { + execIDs = append(execIDs, id) + } + data := &inspect.ContainerInspectData{ ID: config.ID, Created: config.CreatedTime, @@ -50,7 +55,7 @@ func (c *Container) getContainerInspectData(size bool, driverData *inspect.Data) MountLabel: config.MountLabel, ProcessLabel: spec.Process.SelinuxLabel, AppArmorProfile: spec.Process.ApparmorProfile, - ExecIDs: []string{}, //TODO + ExecIDs: execIDs, GraphDriver: driverData, Mounts: spec.Mounts, NetworkSettings: &inspect.NetworkSettings{ diff --git a/libpod/container_internal.go b/libpod/container_internal.go index 37a70a152..61f3410c9 100644 --- a/libpod/container_internal.go +++ b/libpod/container_internal.go @@ -100,6 +100,11 @@ 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) +} + // Sync this container with on-disk state and runc status // Should only be called with container lock held // This function should suffice to ensure a container's state is accurate and diff --git a/libpod/oci.go b/libpod/oci.go index 225643f39..f25c6bdb9 100644 --- a/libpod/oci.go +++ b/libpod/oci.go @@ -471,7 +471,15 @@ func (r *OCIRuntime) unpauseContainer(ctr *Container) error { // TODO: Add --detach support // TODO: Convert to use conmon // TODO: add --pid-file and use that to generate exec session tracking -func (r *OCIRuntime) execContainer(c *Container, cmd []string, tty bool, user string, capAdd, env []string) error { +func (r *OCIRuntime) execContainer(c *Container, cmd, capAdd, env []string, tty bool, user, sessionID string) (*exec.Cmd, error) { + if len(cmd) == 0 { + return nil, errors.Wrapf(ErrInvalidArg, "must provide a command to execute") + } + + if sessionID == "" { + return nil, errors.Wrapf(ErrEmptyID, "must provide a session ID for exec") + } + args := []string{} // TODO - should we maintain separate logpaths for exec sessions? @@ -481,6 +489,8 @@ func (r *OCIRuntime) execContainer(c *Container, cmd []string, tty bool, user st args = append(args, "--cwd", c.config.Spec.Process.Cwd) + args = append(args, "--pid-file", c.execPidPath(sessionID)) + if tty { args = append(args, "--tty") } @@ -512,9 +522,5 @@ func (r *OCIRuntime) execContainer(c *Container, cmd []string, tty bool, user st execCmd.Stderr = os.Stderr execCmd.Stdin = os.Stdin - if err := execCmd.Start(); err != nil { - return errors.Wrapf(err, "error starting exec command for container %s", c.ID()) - } - - return execCmd.Wait() + return execCmd, nil } diff --git a/libpod/util.go b/libpod/util.go index 0c6700fbf..ca93fc097 100644 --- a/libpod/util.go +++ b/libpod/util.go @@ -107,3 +107,32 @@ func MountExists(specMounts []spec.Mount, dest string) bool { } return false } + +// WaitForFile waits until a file has been created or the given timeout has occurred +func WaitForFile(path string, timeout time.Duration) error { + done := make(chan struct{}) + chControl := make(chan struct{}) + go func() { + for { + select { + case <-chControl: + return + default: + _, err := os.Stat(path) + if err == nil { + close(done) + return + } + time.Sleep(25 * time.Millisecond) + } + } + }() + + select { + case <-done: + return nil + case <-time.After(timeout): + close(chControl) + return errors.Wrapf(ErrInternal, "timed out waiting for file %s", path) + } +} |