pod config: add a `CreateCommand` field

Add a `CreateCommand` field to the pod config which includes the entire
`os.Args` at pod-creation.  Similar to the already existing field in a
container config, we need this information to properly generate generic
systemd unit files for pods.  It's a prerequisite to support the `--new`
flag for pods.

Also add the `CreateCommand` to the pod-inspect data, which can come in
handy for debugging, general inspection and certainly for the tests that
are added along with the other changes.

Signed-off-by: Valentin Rothberg <rothberg@redhat.com>

libpod/define/pod_inspect.go

@@ -18,6 +18,9 @@ type InspectPodData struct {
 	Namespace string `json:"Namespace,omitempty"`
 	// Created is the time when the pod was created.
 	Created time.Time
+	// CreateCommand is the full command plus arguments of the process the
+	// container has been created with.
+	CreateCommand []string `json:"CreateCommand,omitempty"`
 	// State represents the current state of the pod.
 	State string `json:"State"`
 	// Hostname is the hostname that the pod will set.

libpod/options.go

@@ -1538,6 +1538,18 @@ func WithPodHostname(hostname string) PodCreateOption {
 	}
 }
 
+// WithPodCreateCommand adds the full command plus arguments of the current
+// process to the pod config.
+func WithPodCreateCommand() PodCreateOption {
+	return func(pod *Pod) error {
+		if pod.valid {
+			return define.ErrPodFinalized
+		}
+		pod.config.CreateCommand = os.Args
+		return nil
+	}
+}
+
 // WithPodLabels sets the labels of a pod.
 func WithPodLabels(labels map[string]string) PodCreateOption {
 	return func(pod *Pod) error {

libpod/pod.go

@@ -64,6 +64,10 @@ type PodConfig struct {
 	// Time pod was created
 	CreatedTime time.Time `json:"created"`
 
+	// CreateCommand is the full command plus arguments of the process the
+	// container has been created with.
+	CreateCommand []string `json:"CreateCommand,omitempty"`
+
 	// ID of the pod's lock
 	LockID uint32 `json:"lockID"`
 }

libpod/pod_api.go

@@ -489,6 +489,7 @@ func (p *Pod) Inspect() (*define.InspectPodData, error) {
 		Name:             p.Name(),
 		Namespace:        p.Namespace(),
 		Created:          p.CreatedTime(),
+		CreateCommand:    p.config.CreateCommand,
 		State:            podState,
 		Hostname:         p.config.Hostname,
 		Labels:           p.Labels(),

pkg/specgen/generate/pod_create.go

@@ -93,5 +93,6 @@ func createPodOptions(p *specgen.PodSpecGenerator) ([]libpod.PodCreateOption, er
 		options = append(options, libpod.WithInfraContainerPorts(ports))
 	}
 	options = append(options, libpod.WithPodCgroups())
+	options = append(options, libpod.WithPodCreateCommand())
 	return options, nil
 }

test/e2e/pod_inspect_test.go

@@ -57,4 +57,26 @@ var _ = Describe("Podman pod inspect", func() {
 		podData := inspect.InspectPodToJSON()
 		Expect(podData.ID).To(Equal(podid))
 	})
+
+	It("podman pod inspect (CreateCommand)", func() {
+		podName := "myTestPod"
+		createCommand := []string{"pod", "create", "--name", podName, "--hostname", "rudolph", "--share", "net"}
+
+		// Create the pod.
+		session := podmanTest.Podman(createCommand)
+		session.WaitWithDefaultTimeout()
+		Expect(session.ExitCode()).To(Equal(0))
+
+		// Inspect the pod and make sure that the create command is
+		// exactly how we created the pod.
+		inspect := podmanTest.Podman([]string{"pod", "inspect", podName})
+		inspect.WaitWithDefaultTimeout()
+		Expect(inspect.ExitCode()).To(Equal(0))
+		Expect(inspect.IsJSONOutputValid()).To(BeTrue())
+		podData := inspect.InspectPodToJSON()
+		// Let's get the last len(createCommand) items in the command.
+		inspectCreateCommand := podData.CreateCommand
+		index := len(inspectCreateCommand) - len(createCommand)
+		Expect(inspectCreateCommand[index:]).To(Equal(createCommand))
+	})
 })