kube play: support auto updates and rollbacks

Add auto-update support to `podman kube play`.  Auto-update policies can
be configured for:
 * the entire pod via the `io.containers.autoupdate` annotation
 * a specific container via the `io.containers.autoupdate/$name` annotation

To make use of rollbacks, the `io.containers.sdnotify` policy should be
set to `container` such that the workload running _inside_ the container
can send the READY message via the NOTIFY_SOCKET once ready.  For
further details on auto updates and rollbacks, please refer to the
specific article [1].

Since auto updates and rollbacks bases on Podman's systemd integration,
the k8s YAML must be executed in the `podman-kube@` systemd template.
For further details on how to run k8s YAML in systemd via Podman, please
refer to the specific article [2].

An examplary k8s YAML may look as follows:
```YAML
apiVersion: v1
kind: Pod
metadata:
  annotations:
      io.containers.autoupdate: "local"
      io.containers.autoupdate/b: "registry"
  labels:
    app: test
  name: test_pod
spec:
  containers:
  - command:
    - top
    image: alpine
    name: a
  - command:
    - top
    image: alpine
    name: b
```

[1] https://www.redhat.com/sysadmin/podman-auto-updates-rollbacks
[2] https://www.redhat.com/sysadmin/kubernetes-workloads-podman-systemd

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

1 files changed, 22 insertions, 13 deletions

diff --git a/pkg/domain/infra/abi/play.go b/pkg/domain/infra/abi/play.go
index 6ea20a4f2..12786afcd 100644
--- a/pkg/domain/infra/abi/play.go
+++ b/pkg/domain/infra/abi/play.go
@@ -661,9 +661,10 @@ func (ic *ContainerEngine) playKubePod(ctx context.Context, podName string, podY
 
 		opts = append(opts, libpod.WithSdNotifyMode(sdNotifyMode))
 
+		var proxy *notifyproxy.NotifyProxy
 		// Create a notify proxy for the container.
 		if sdNotifyMode != "" && sdNotifyMode != define.SdNotifyModeIgnore {
-			proxy, err := notifyproxy.New("")
+			proxy, err = notifyproxy.New("")
 			if err != nil {
 				return nil, err
 			}
@@ -675,6 +676,9 @@ func (ic *ContainerEngine) playKubePod(ctx context.Context, podName string, podY
 		if err != nil {
 			return nil, err
 		}
+		if proxy != nil {
+			proxy.AddContainer(ctr)
+		}
 		containers = append(containers, ctr)
 	}
 
@@ -774,21 +778,26 @@ func (ic *ContainerEngine) getImageAndLabelInfo(ctx context.Context, cwd string,
 	}
 
 	// Handle kube annotations
-	for k, v := range annotations {
-		switch k {
-		// Auto update annotation without container name will apply to
-		// all containers within the pod
-		case autoupdate.Label, autoupdate.AuthfileLabel:
-			labels[k] = v
-		// Auto update annotation with container name will apply only
-		// to the specified container
-		case fmt.Sprintf("%s/%s", autoupdate.Label, container.Name),
-			fmt.Sprintf("%s/%s", autoupdate.AuthfileLabel, container.Name):
-			prefixAndCtr := strings.Split(k, "/")
-			labels[prefixAndCtr[0]] = v
+	setLabel := func(label string) {
+		var result string
+		ctrSpecific := fmt.Sprintf("%s/%s", label, container.Name)
+		for k, v := range annotations {
+			switch k {
+			case label:
+				result = v
+			case ctrSpecific:
+				labels[label] = v
+				return
+			}
+		}
+		if result != "" {
+			labels[label] = result
 		}
 	}
 
+	setLabel(autoupdate.Label)
+	setLabel(autoupdate.AuthfileLabel)
+
 	return pulledImage, labels, nil
 }