kube play: sd-notify integration

Integrate sd-notify policies into `kube play`.  The policies can be
configured for all contianers via the `io.containers.sdnotify`
annotation or for indidivual containers via the
`io.containers.sdnotify/$name` annotation.

The `kube play` process will wait for all containers to be ready by
waiting for the individual `READY=1` messages which are received via
the `pkg/systemd/notifyproxy` proxy mechanism.

Also update the simple "container" sd-notify test as it did not fully
test the expected behavior which became obvious when adding the new
tests.

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

2 files changed, 20 insertions, 7 deletions

diff --git a/libpod/define/config.go b/libpod/define/config.go
index 0181bd31c..34c1a675d 100644
--- a/libpod/define/config.go
+++ b/libpod/define/config.go
@@ -81,13 +81,6 @@ const NoLogging = "none"
 // PassthroughLogging is the string conmon expects when specifying to use the passthrough driver
 const PassthroughLogging = "passthrough"
 
-// Strings used for --sdnotify option to podman
-const (
-	SdNotifyModeContainer = "container"
-	SdNotifyModeConmon    = "conmon"
-	SdNotifyModeIgnore    = "ignore"
-)
-
 // DefaultRlimitValue is the value set by default for nofile and nproc
 const RLimitDefaultValue = uint64(1048576)
 
diff --git a/libpod/define/sdnotify.go b/libpod/define/sdnotify.go
new file mode 100644
index 000000000..1d548c764
--- /dev/null
+++ b/libpod/define/sdnotify.go
@@ -0,0 +1,20 @@
+package define
+
+import "fmt"
+
+// Strings used for --sdnotify option to podman
+const (
+	SdNotifyModeContainer = "container"
+	SdNotifyModeConmon    = "conmon"
+	SdNotifyModeIgnore    = "ignore"
+)
+
+// ValidateSdNotifyMode validates the specified mode.
+func ValidateSdNotifyMode(mode string) error {
+	switch mode {
+	case "", SdNotifyModeContainer, SdNotifyModeConmon, SdNotifyModeIgnore:
+		return nil
+	default:
+		return fmt.Errorf("%w: invalid sdnotify value %q: must be %s, %s or %s", ErrInvalidArg, mode, SdNotifyModeContainer, SdNotifyModeConmon, SdNotifyModeIgnore)
+	}
+}