pod create: add --infra-conmon-pidfile

Add an `--infra-conmon-pidfile` flag to `podman-pod-create` to write the
infra container's conmon process ID to a specified path.  Several
container sub-commands already support `--conmon-pidfile` which is
especially helpful to allow for systemd to access and track the conmon
processes.  This allows for easily tracking the conmon process of a
pod's infra container.

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

pkg/specgen/generate/pod_create.go

@@ -94,5 +94,8 @@ func createPodOptions(p *specgen.PodSpecGenerator) ([]libpod.PodCreateOption, er
 	}
 	options = append(options, libpod.WithPodCgroups())
 	options = append(options, libpod.WithPodCreateCommand())
+	if len(p.InfraConmonPidFile) > 0 {
+		options = append(options, libpod.WithInfraConmonPidFile(p.InfraConmonPidFile))
+	}
 	return options, nil
 }

pkg/specgen/podspecgen.go

@@ -25,6 +25,9 @@ type PodBasicConfig struct {
 	// InfraCommand and InfraImages in this struct.
 	// Optional.
 	NoInfra bool `json:"no_infra,omitempty"`
+	// InfraConmonPidFile is a custom path to store the infra container's
+	// conmon PID.
+	InfraConmonPidFile string `json:"infra_conmon_pid_file,omitempty"`
 	// InfraCommand sets the command that will be used to start the infra
 	// container.
 	// If not set, the default set in the Libpod configuration file will be