Add support for the unless-stopped restart policy

We initially believed that implementing this required support for
restarting containers after reboot, but this is not the case.
The unless-stopped restart policy acts identically to the always
restart policy except in cases related to reboot (which we do not
support yet), but it does not require that support for us to
implement it.

Changes themselves are quite simple, we need a new restart policy
constant, we need to remove existing checks that block creation
of containers when unless-stopped was used, and we need to update
the manpages.

Fixes #6508

Signed-off-by: Matthew Heon <matthew.heon@pm.me>

2 files changed, 5 insertions, 1 deletions

diff --git a/libpod/container.go b/libpod/container.go
index d4a779b13..20702903e 100644
--- a/libpod/container.go
+++ b/libpod/container.go
@@ -97,6 +97,10 @@ const (
 	// RestartPolicyOnFailure restarts the container on non-0 exit code,
 	// with an optional maximum number of retries.
 	RestartPolicyOnFailure = "on-failure"
+	// RestartPolicyUnlessStopped unconditionally restarts unless stopped
+	// by the user. It is identical to Always except with respect to
+	// handling of system restart, which Podman does not yet support.
+	RestartPolicyUnlessStopped = "unless-stopped"
 )
 
 // Container is a single OCI container.
diff --git a/libpod/options.go b/libpod/options.go
index 5a0f60093..e1c4ddf06 100644
--- a/libpod/options.go
+++ b/libpod/options.go
@@ -1285,7 +1285,7 @@ func WithRestartPolicy(policy string) CtrCreateOption {
 		}
 
 		switch policy {
-		case RestartPolicyNone, RestartPolicyNo, RestartPolicyOnFailure, RestartPolicyAlways:
+		case RestartPolicyNone, RestartPolicyNo, RestartPolicyOnFailure, RestartPolicyAlways, RestartPolicyUnlessStopped:
 			ctr.config.RestartPolicy = policy
 		default:
 			return errors.Wrapf(define.ErrInvalidArg, "%q is not a valid restart policy", policy)