Kube Play: use passthrough as the default log-driver if service-container is set

cmd/podman/kube/play.go

@@ -73,6 +73,7 @@ var (
   podman play kube --creds user:password --seccomp-profile-root /custom/path apache.yml
   podman play kube https://example.com/nginx.yml`,
 	}
+	logDriverFlagName = "log-driver"
 )
 
 func init() {
@@ -116,7 +117,6 @@ func playFlags(cmd *cobra.Command) {
 	flags.IPSliceVar(&playOptions.StaticIPs, staticIPFlagName, nil, "Static IP addresses to assign to the pods")
 	_ = cmd.RegisterFlagCompletionFunc(staticIPFlagName, completion.AutocompleteNone)
 
-	logDriverFlagName := "log-driver"
 	flags.StringVar(&playOptions.LogDriver, logDriverFlagName, common.LogDriver(), "Logging driver for the container")
 	_ = cmd.RegisterFlagCompletionFunc(logDriverFlagName, common.AutocompleteLogDriver)
 
@@ -247,6 +247,15 @@ func play(cmd *cobra.Command, args []string) error {
 		return errors.New("--force may be specified only with --down")
 	}
 
+	// When running under Systemd use passthrough as the default log-driver.
+	// When doing so, the journal socket is passed to the containers as-is which has two advantages:
+	// 1. journald can see who the actual sender of the log event is,
+	//    rather than thinking everything comes from the conmon process
+	// 2. conmon will not have to copy all the log data
+	if !cmd.Flags().Changed(logDriverFlagName) && playOptions.ServiceContainer {
+		playOptions.LogDriver = define.PassthroughLogging
+	}
+
 	reader, err := readerFromArg(args[0])
 	if err != nil {
 		return err

test/system/250-systemd.bats

@@ -414,6 +414,12 @@ EOF
     run_podman 125 container rm $service_container
     is "$output" "Error: container .* is the service container of pod(s) .* and cannot be removed without removing the pod(s)"
 
+    # Verify that the log-driver for the Pod's containers is passthrough
+    for name in "a" "b"; do
+        run_podman container inspect test_pod-${name} --format "{{.HostConfig.LogConfig.Type}}"
+        is $output "passthrough"
+    done
+
     # Add a simple `auto-update --dry-run` test here to avoid too much redundancy
     # with 255-auto-update.bats
     run_podman auto-update --dry-run --format "{{.Unit}},{{.Container}},{{.Image}},{{.Updated}},{{.Policy}}"

test/system/260-sdnotify.bats

@@ -225,7 +225,7 @@ EOF
     wait_for_file $_SOCAT_LOG
 
     # Will run until all containers have stopped.
-    run_podman play kube --service-container=true $yaml_source
+    run_podman play kube --service-container=true --log-driver journald $yaml_source
     run_podman container wait $service_container test_pod-test
 
     # Make sure the containers have the correct policy.
@@ -302,7 +302,7 @@ EOF
     # Run `play kube` in the background as it will wait for all containers to
     # send the READY=1 message.
     timeout --foreground -v --kill=10 60 \
-        $PODMAN play kube --service-container=true $yaml_source &>/dev/null &
+        $PODMAN play kube --service-container=true --log-driver journald $yaml_source &>/dev/null &
 
     # Wait for both containers to be running
     for i in $(seq 1 20); do

test/system/700-play.bats

@@ -126,7 +126,7 @@ EOF
     # Run `play kube` in the background as it will wait for the service
     # container to exit.
     timeout --foreground -v --kill=10 60 \
-        $PODMAN play kube --service-container=true $yaml_source &>/dev/null &
+        $PODMAN play kube --service-container=true --log-driver journald $yaml_source &>/dev/null &
 
     # Wait for the container to be running
     container_a=test_pod-test