summaryrefslogtreecommitdiff
path: root/libpod
diff options
context:
space:
mode:
Diffstat (limited to 'libpod')
-rw-r--r--libpod/container_api.go84
-rw-r--r--libpod/container_inspect.go7
-rw-r--r--libpod/container_internal.go5
-rw-r--r--libpod/oci.go18
-rw-r--r--libpod/util.go29
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)
+ }
+}