kube: Add support for podman pod logs

Following PR adds support for `kubectl` like `pod logs` to podman.
Usage `podman pod logs <podIDorName` gives a stream of logs for all
the containers within the pod with **containername** as a field.

Just like **`kubectl`** also supports `podman pod logs -c ctrIDorName podIDorName`
to limit the log stream to any of the specificied container which belongs to pod.

Signed-off-by: Aditya Rajan <arajan@redhat.com>

4 files changed, 78 insertions, 0 deletions

diff --git a/pkg/domain/entities/engine_container.go b/pkg/domain/entities/engine_container.go
index bd011d309..93fa7a20f 100644
--- a/pkg/domain/entities/engine_container.go
+++ b/pkg/domain/entities/engine_container.go
@@ -72,6 +72,7 @@ type ContainerEngine interface {
 	PodExists(ctx context.Context, nameOrID string) (*BoolReport, error)
 	PodInspect(ctx context.Context, options PodInspectOptions) (*PodInspectReport, error)
 	PodKill(ctx context.Context, namesOrIds []string, options PodKillOptions) ([]*PodKillReport, error)
+	PodLogs(ctx context.Context, pod string, options PodLogsOptions) error
 	PodPause(ctx context.Context, namesOrIds []string, options PodPauseOptions) ([]*PodPauseReport, error)
 	PodPrune(ctx context.Context, options PodPruneOptions) ([]*PodPruneReport, error)
 	PodPs(ctx context.Context, options PodPSOptions) ([]*ListPodsReport, error)
diff --git a/pkg/domain/entities/pods.go b/pkg/domain/entities/pods.go
index 10bd7e5ce..d9dd0c532 100644
--- a/pkg/domain/entities/pods.go
+++ b/pkg/domain/entities/pods.go
@@ -133,6 +133,14 @@ type PodCreateOptions struct {
 	Userns             specgen.Namespace
 }
 
+// PodLogsOptions describes the options to extract pod logs.
+type PodLogsOptions struct {
+	// Other fields are exactly same as ContainerLogOpts
+	ContainerLogsOptions
+	// If specified will only fetch the logs of specified container
+	ContainerName string
+}
+
 type ContainerCreateOptions struct {
 	Annotation        []string
 	Attach            []string
@@ -426,3 +434,22 @@ func ValidatePodStatsOptions(args []string, options *PodStatsOptions) error {
 		return errors.New("--all, --latest and arguments cannot be used together")
 	}
 }
+
+// Converts PodLogOptions to ContainerLogOptions
+func PodLogsOptionsToContainerLogsOptions(options PodLogsOptions) ContainerLogsOptions {
+	// PodLogsOptions are similar but contains few extra fields like ctrName
+	// So cast other values as is so we can re-use the code
+	containerLogsOpts := ContainerLogsOptions{
+		Details:      options.Details,
+		Latest:       options.Latest,
+		Follow:       options.Follow,
+		Names:        options.Names,
+		Since:        options.Since,
+		Until:        options.Until,
+		Tail:         options.Tail,
+		Timestamps:   options.Timestamps,
+		StdoutWriter: options.StdoutWriter,
+		StderrWriter: options.StderrWriter,
+	}
+	return containerLogsOpts
+}
diff --git a/pkg/domain/infra/abi/pods.go b/pkg/domain/infra/abi/pods.go
index 98233f60d..6b432c214 100644
--- a/pkg/domain/infra/abi/pods.go
+++ b/pkg/domain/infra/abi/pods.go
@@ -83,6 +83,46 @@ func (ic *ContainerEngine) PodKill(ctx context.Context, namesOrIds []string, opt
 	return reports, nil
 }
 
+func (ic *ContainerEngine) PodLogs(ctx context.Context, nameOrID string, options entities.PodLogsOptions) error {
+	// Implementation accepts slice
+	podName := []string{nameOrID}
+	pod, err := getPodsByContext(false, options.Latest, podName, ic.Libpod)
+	if err != nil {
+		return err
+	}
+	// Get pod containers
+	podCtrs, err := pod[0].AllContainers()
+	if err != nil {
+		return err
+	}
+
+	ctrNames := []string{}
+	// Check if `kubectl pod logs -c ctrname <podname>` alike command is used
+	if options.ContainerName != "" {
+		ctrFound := false
+		for _, ctr := range podCtrs {
+			if ctr.ID() == options.ContainerName || ctr.Name() == options.ContainerName {
+				ctrNames = append(ctrNames, options.ContainerName)
+				ctrFound = true
+			}
+		}
+		if !ctrFound {
+			return errors.Wrapf(define.ErrNoSuchCtr, "container %s is not in pod %s", options.ContainerName, nameOrID)
+		}
+	} else {
+		// No container name specified select all containers
+		for _, ctr := range podCtrs {
+			ctrNames = append(ctrNames, ctr.Name())
+		}
+	}
+
+	// PodLogsOptions are similar but contains few extra fields like ctrName
+	// So cast other values as is so we can re-use the code
+	containerLogsOpts := entities.PodLogsOptionsToContainerLogsOptions(options)
+
+	return ic.ContainerLogs(ctx, ctrNames, containerLogsOpts)
+}
+
 func (ic *ContainerEngine) PodPause(ctx context.Context, namesOrIds []string, options entities.PodPauseOptions) ([]*entities.PodPauseReport, error) {
 	reports := []*entities.PodPauseReport{}
 	pods, err := getPodsByContext(options.All, options.Latest, namesOrIds, ic.Libpod)
diff --git a/pkg/domain/infra/tunnel/pods.go b/pkg/domain/infra/tunnel/pods.go
index 480adb88a..8139216b3 100644
--- a/pkg/domain/infra/tunnel/pods.go
+++ b/pkg/domain/infra/tunnel/pods.go
@@ -42,6 +42,16 @@ func (ic *ContainerEngine) PodKill(ctx context.Context, namesOrIds []string, opt
 	return reports, nil
 }
 
+func (ic *ContainerEngine) PodLogs(_ context.Context, nameOrIDs string, options entities.PodLogsOptions) error {
+	// PodLogsOptions are similar but contains few extra fields like ctrName
+	// So cast other values as is so we can re-use the code
+	containerLogsOpts := entities.PodLogsOptionsToContainerLogsOptions(options)
+
+	// interface only accepts slice, keep everything consistent
+	name := []string{options.ContainerName}
+	return ic.ContainerLogs(nil, name, containerLogsOpts)
+}
+
 func (ic *ContainerEngine) PodPause(ctx context.Context, namesOrIds []string, options entities.PodPauseOptions) ([]*entities.PodPauseReport, error) {
 	foundPods, err := getPodsByContext(ic.ClientCtx, options.All, namesOrIds)
 	if err != nil {