play kube: service container

Add the notion of a "service container" to play kube.  A service
container is started before the pods in play kube and is (reverse)
linked to them.  The service container is stopped/removed *after*
all pods it is associated with are stopped/removed.

In other words, a service container tracks the entire life cycle
of a service started via `podman play kube`.  This is required to
enable `play kube` in a systemd unit file.

The service container is only used when the `--service-container`
flag is set on the CLI.  This flag has been marked as hidden as it
is not meant to be used outside the context of `play kube`.  It is
further not supported on the remote client.

The wiring with systemd will be done in a later commit.

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

1 files changed, 8 insertions, 0 deletions

diff --git a/libpod/container.go b/libpod/container.go
index d7af9a100..64b4453fb 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -211,6 +211,14 @@ type ContainerState struct {
 	// network and an interface names
 	NetInterfaceDescriptions ContainerNetworkDescriptions `json:"networkDescriptions,omitempty"`
 
+	// Service indicates that container is the service container of a
+	// service. A service consists of one or more pods.  The service
+	// container is started before all pods and is stopped when the last
+	// pod stops. The service container allows for tracking and managing
+	// the entire life cycle of service which may be started via
+	// `podman-play-kube`.
+	Service Service
+
 	// containerPlatformState holds platform-specific container state.
 	containerPlatformState