health check: add on-failure actions

For systems that have extreme robustness requirements (edge devices,
particularly those in difficult to access environments), it is important
that applications continue running in all circumstances. When the
application fails, Podman must restart it automatically to provide this
robustness. Otherwise, these devices may require customer IT to
physically gain access to restart, which can be prohibitively difficult.

Add a new `--on-failure` flag that supports four actions:

- **none**: Take no action.

- **kill**: Kill the container.

- **restart**: Restart the container.  Do not combine the `restart`
               action with the `--restart` flag.  When running inside of
               a systemd unit, consider using the `kill` or `stop`
               action instead to make use of systemd's restart policy.

- **stop**: Stop the container.

To remain backwards compatible, **none** is the default action.

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

1 files changed, 4 insertions, 0 deletions

diff --git a/libpod/container_validate.go b/libpod/container_validate.go
index da33f6db7..f4611ecce 100644
--- a/libpod/container_validate.go
+++ b/libpod/container_validate.go
@@ -137,5 +137,9 @@ func (c *Container) validate() error {
 	if c.config.SdNotifyMode == define.SdNotifyModeIgnore && len(c.config.SdNotifySocket) > 0 {
 		return fmt.Errorf("cannot set sd-notify socket %q with sd-notify mode %q", c.config.SdNotifySocket, c.config.SdNotifyMode)
 	}
+
+	if c.config.HealthCheckOnFailureAction != define.HealthCheckOnFailureActionNone && c.config.HealthCheckConfig == nil {
+		return fmt.Errorf("cannot set on-failure action to %s without a health check", c.config.HealthCheckOnFailureAction.String())
+	}
 	return nil
 }