pod: add exit policies

Add the notion of an "exit policy" to a pod.  This policy controls the
behaviour when the last container of pod exits.  Initially, there are
two policies:

 - "continue" : the pod continues running. This is the default policy
                when creating a pod.

 - "stop" : stop the pod when the last container exits. This is the
            default behaviour for `play kube`.

In order to implement the deferred stop of a pod, add a worker queue to
the libpod runtime.  The queue will pick up work items and in this case
helps resolve dead locks that would otherwise occur if we attempted to
stop a pod during container cleanup.

Note that the default restart policy of `play kube` is "Always".  Hence,
in order to really solve #13464, the YAML files must set a custom
restart policy; the tests use "OnFailure".

Fixes: #13464
Signed-off-by: Valentin Rothberg <vrothberg@redhat.com>

4 files changed, 11 insertions, 1 deletions

diff --git a/pkg/domain/entities/pods.go b/pkg/domain/entities/pods.go
index 1e25e0872..a19edcbf0 100644
--- a/pkg/domain/entities/pods.go
+++ b/pkg/domain/entities/pods.go
@@ -122,6 +122,7 @@ type PodCreateOptions struct {
 	CreateCommand      []string          `json:"create_command,omitempty"`
 	Devices            []string          `json:"devices,omitempty"`
 	DeviceReadBPs      []string          `json:"device_read_bps,omitempty"`
+	ExitPolicy         string            `json:"exit_policy,omitempty"`
 	Hostname           string            `json:"hostname,omitempty"`
 	Infra              bool              `json:"infra,omitempty"`
 	InfraImage         string            `json:"infra_image,omitempty"`
@@ -319,6 +320,7 @@ func ToPodSpecGen(s specgen.PodSpecGenerator, p *PodCreateOptions) (*specgen.Pod
 	}
 	s.Pid = out
 	s.Hostname = p.Hostname
+	s.ExitPolicy = p.ExitPolicy
 	s.Labels = p.Labels
 	s.Devices = p.Devices
 	s.SecurityOpt = p.SecurityOpt
diff --git a/pkg/domain/infra/abi/play.go b/pkg/domain/infra/abi/play.go
index 0da07bab8..b3ded7db6 100644
--- a/pkg/domain/infra/abi/play.go
+++ b/pkg/domain/infra/abi/play.go
@@ -197,7 +197,11 @@ func (ic *ContainerEngine) playKubePod(ctx context.Context, podName string, podY
 		return nil, errors.Errorf("pod does not have a name")
 	}
 
-	podOpt := entities.PodCreateOptions{Infra: true, Net: &entities.NetOptions{NoHosts: options.NoHosts}}
+	podOpt := entities.PodCreateOptions{
+		Infra:      true,
+		Net:        &entities.NetOptions{NoHosts: options.NoHosts},
+		ExitPolicy: string(config.PodExitPolicyStop),
+	}
 	podOpt, err = kube.ToPodOpt(ctx, podName, podOpt, podYAML)
 	if err != nil {
 		return nil, err
diff --git a/pkg/specgen/generate/pod_create.go b/pkg/specgen/generate/pod_create.go
index a3408b402..fce32d688 100644
--- a/pkg/specgen/generate/pod_create.go
+++ b/pkg/specgen/generate/pod_create.go
@@ -197,6 +197,8 @@ func createPodOptions(p *specgen.PodSpecGenerator) ([]libpod.PodCreateOption, er
 		options = append(options, libpod.WithPodHostname(p.Hostname))
 	}
 
+	options = append(options, libpod.WithPodExitPolicy(p.ExitPolicy))
+
 	return options, nil
 }
 
diff --git a/pkg/specgen/podspecgen.go b/pkg/specgen/podspecgen.go
index 759caa0c0..1bb64448f 100644
--- a/pkg/specgen/podspecgen.go
+++ b/pkg/specgen/podspecgen.go
@@ -19,6 +19,8 @@ type PodBasicConfig struct {
 	// all containers in the pod as long as the UTS namespace is shared.
 	// Optional.
 	Hostname string `json:"hostname,omitempty"`
+	// ExitPolicy determines the pod's exit and stop behaviour.
+	ExitPolicy string `json:"exit_policy,omitempty"`
 	// Labels are key-value pairs that are used to add metadata to pods.
 	// Optional.
 	Labels map[string]string `json:"labels,omitempty"`