Add support for launching containers without CGroups

This is mostly used with Systemd, which really wants to manage
CGroups itself when managing containers via unit file.

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

2 files changed, 16 insertions, 0 deletions

diff --git a/pkg/spec/createconfig.go b/pkg/spec/createconfig.go
index 3f70e5935..c17172016 100644
--- a/pkg/spec/createconfig.go
+++ b/pkg/spec/createconfig.go
@@ -64,6 +64,7 @@ type CreateConfig struct {
 	CidFile            string
 	ConmonPidFile      string
 	Cgroupns           string
+	Cgroups            string
 	CgroupParent       string            // cgroup-parent
 	Command            []string          // Full command that will be used
 	UserCommand        []string          // User-entered command (or image CMD)
@@ -206,6 +207,9 @@ func (c *CreateConfig) getContainerCreateOptions(runtime *libpod.Runtime, pod *l
 		logrus.Debugf("adding container to pod %s", c.Pod)
 		options = append(options, runtime.WithPod(pod))
 	}
+	if c.Cgroups == "disabled" {
+		options = append(options, libpod.WithNoCgroups())
+	}
 	if len(c.PortBindings) > 0 {
 		portBindings, err = c.CreatePortBindings()
 		if err != nil {
diff --git a/pkg/spec/spec.go b/pkg/spec/spec.go
index 44bbda885..38f9c7306 100644
--- a/pkg/spec/spec.go
+++ b/pkg/spec/spec.go
@@ -396,6 +396,18 @@ func (config *CreateConfig) createConfigToOCISpec(runtime *libpod.Runtime, userM
 		}
 	}
 
+	switch config.Cgroups {
+	case "disabled":
+		if addedResources {
+			return nil, errors.New("cannot specify resource limits when cgroups are disabled is specified")
+		}
+		configSpec.Linux.Resources = &spec.LinuxResources{}
+	case "enabled", "":
+		// Do nothing
+	default:
+		return nil, errors.New("unrecognized option for cgroups; supported are 'default' and 'disabled'")
+	}
+
 	// Add annotations
 	if configSpec.Annotations == nil {
 		configSpec.Annotations = make(map[string]string)