kpod exec

Initial wiring of kpod exec. We wont support the following options
for exec:

* detach -- unsure of use case
* detach-keys -- not supported by runc
* interactive -- all terminals will be interactive

Not adding exec tests as we need to think about how to support a
test that requires console access but our CI tests have no console.

Signed-off-by: baude <bbaude@redhat.com>

3 files changed, 154 insertions, 3 deletions

diff --git a/libpod/container.go b/libpod/container.go
index 40aa689ff..474d4be95 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -14,6 +14,7 @@ import (
 
 	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/archive"
+	"github.com/docker/docker/daemon/caps"
 	"github.com/docker/docker/pkg/mount"
 	"github.com/docker/docker/pkg/namesgenerator"
 	"github.com/docker/docker/pkg/stringid"
@@ -552,9 +553,36 @@ func (c *Container) Kill(signal uint) error {
 }
 
 // Exec starts a new process inside the container
-// Returns fully qualified URL of streaming server for executed process
-func (c *Container) Exec(cmd []string, tty bool, stdin bool) (string, error) {
-	return "", ErrNotImplemented
+func (c *Container) Exec(tty, privileged bool, env, cmd []string, user string) error {
+	var capList []string
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	if err := c.syncContainer(); err != nil {
+		return err
+	}
+
+	conState := c.state.State
+
+	if conState != ContainerStateRunning {
+		return errors.Errorf("cannot attach to container that is not running")
+	}
+	if privileged {
+		capList = caps.GetAllCapabilities()
+	}
+	globalOpts := runcGlobalOptions{
+		log: c.LogPath(),
+	}
+	execOpts := runcExecOptions{
+		capAdd:  capList,
+		pidFile: filepath.Join(c.state.RunDir, fmt.Sprintf("%s-execpid", stringid.GenerateNonCryptoID()[:12])),
+		env:     env,
+		user:    user,
+		cwd:     c.config.Spec.Process.Cwd,
+		tty:     tty,
+	}
+
+	return c.runtime.ociRuntime.execContainer(c, cmd, globalOpts, execOpts)
 }
 
 // Attach attaches to a container
diff --git a/libpod/oci.go b/libpod/oci.go
index 6ea6bb64f..323e97273 100644
--- a/libpod/oci.go
+++ b/libpod/oci.go
@@ -454,3 +454,9 @@ func (r *OCIRuntime) pauseContainer(ctr *Container) error {
 func (r *OCIRuntime) unpauseContainer(ctr *Container) error {
 	return utils.ExecCmdWithStdStreams(os.Stdin, os.Stdout, os.Stderr, r.path, "resume", ctr.ID())
 }
+
+//execContiner executes a command in a running container
+func (r *OCIRuntime) execContainer(c *Container, cmd []string, globalOpts runcGlobalOptions, commandOpts runcExecOptions) error {
+	r.RuncExec(c, cmd, globalOpts, commandOpts)
+	return nil
+}
diff --git a/libpod/runc.go b/libpod/runc.go
new file mode 100644
index 000000000..efbb51b24
--- /dev/null
+++ b/libpod/runc.go
@@ -0,0 +1,117 @@
+package libpod
+
+import (
+	"os"
+	"os/exec"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+)
+
+type runcGlobalOptions struct {
+	log           string
+	logFormat     string
+	root          string
+	criu          string
+	systemdCgroup bool
+}
+type runcExecOptions struct {
+	consoleSocket string
+	cwd           string
+	env           []string
+	tty           bool
+	user          string
+	processPath   string
+	detach        bool
+	pidFile       string
+	processLabel  string
+	apparmor      string
+	noNewPrivs    bool
+	capAdd        []string
+}
+
+func parseGlobalOptionsToArgs(opts runcGlobalOptions) []string {
+	args := []string{}
+	if opts.log != "" {
+		args = append(args, "--log", opts.log)
+	}
+	if opts.logFormat != "" {
+		args = append(args, "--log-format", opts.logFormat)
+	}
+	if opts.root != "" {
+		args = append(args, "--root", opts.root)
+	}
+	if opts.criu != "" {
+		args = append(args, "--criu", opts.criu)
+	}
+	if opts.systemdCgroup {
+		args = append(args, "--systemd-cgroup")
+	}
+	return args
+}
+
+// RuncExec executes 'runc --options exec --options cmd'
+func (r *OCIRuntime) RuncExec(container *Container, command []string, globalOpts runcGlobalOptions, execOpts runcExecOptions) error {
+	args := []string{}
+	args = append(args, parseGlobalOptionsToArgs(globalOpts)...)
+	// Add subcommand
+	args = append(args, "exec")
+	// Now add subcommand args
+
+	if execOpts.consoleSocket != "" {
+		args = append(args, "--console-socket", execOpts.consoleSocket)
+	}
+	if execOpts.cwd != "" {
+		args = append(args, "--cwd", execOpts.cwd)
+	}
+
+	if len(execOpts.env) > 0 {
+		for _, envInput := range execOpts.env {
+			args = append(args, "--env", envInput)
+		}
+	}
+	if execOpts.tty {
+		args = append(args, "--tty")
+	}
+	if execOpts.user != "" {
+		args = append(args, "--user", execOpts.user)
+
+	}
+	if execOpts.processPath != "" {
+		args = append(args, "--process", execOpts.processPath)
+	}
+	if execOpts.detach {
+		args = append(args, "--detach")
+	}
+	if execOpts.pidFile != "" {
+		args = append(args, "--pid-file", execOpts.pidFile)
+	}
+	if execOpts.processLabel != "" {
+		args = append(args, "--process-label", execOpts.processLabel)
+	}
+	if execOpts.apparmor != "" {
+		args = append(args, "--apparmor", execOpts.apparmor)
+	}
+	if execOpts.noNewPrivs {
+		args = append(args, "--no-new-privs")
+	}
+	if len(execOpts.capAdd) > 0 {
+		for _, capAddValue := range execOpts.capAdd {
+			args = append(args, "--cap", capAddValue)
+		}
+	}
+
+	// Append Cid
+	args = append(args, container.ID())
+	// Append Cmd
+	args = append(args, command...)
+
+	logrus.Debug("Executing runc command: %s %s", r.path, strings.Join(args, " "))
+	cmd := exec.Command(r.path, args...)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	cmd.Stdin = os.Stdin
+	cmd.Start()
+	err := cmd.Wait()
+	return err
+}