Mount proper cgroup for systemd to manage inside of the container.

We are still requiring oci-systemd-hook to be installed in order to run
systemd within a container.  This patch properly mounts

/sys/fs/cgroup/systemd/libpod_parent/libpod-UUID on /sys/fs/cgroup/systemd inside of container.

Since we need the UUID of the container, we needed to move Systemd to be a config option of the
container.

Signed-off-by: Daniel J Walsh <dwalsh@redhat.com>

2 files changed, 4 insertions, 50 deletions

diff --git a/pkg/spec/createconfig.go b/pkg/spec/createconfig.go
index d34b21189..6ac9d82da 100644
--- a/pkg/spec/createconfig.go
+++ b/pkg/spec/createconfig.go
@@ -319,6 +319,10 @@ func (c *CreateConfig) GetContainerCreateOptions(runtime *libpod.Runtime) ([]lib
 	if c.Interactive {
 		options = append(options, libpod.WithStdin())
 	}
+	if c.Systemd && (strings.HasSuffix(c.Command[0], "init") ||
+		strings.HasSuffix(c.Command[0], "systemd")) {
+		options = append(options, libpod.WithSystemd())
+	}
 	if c.Name != "" {
 		logrus.Debugf("appending name %s", c.Name)
 		options = append(options, libpod.WithName(c.Name))
diff --git a/pkg/spec/spec.go b/pkg/spec/spec.go
index 4c855d659..b1cca2c9e 100644
--- a/pkg/spec/spec.go
+++ b/pkg/spec/spec.go
@@ -5,7 +5,6 @@ import (
 	"path"
 	"strings"
 
-	"github.com/containers/libpod/libpod"
 	"github.com/containers/libpod/pkg/rootless"
 	"github.com/docker/docker/daemon/caps"
 	"github.com/docker/docker/pkg/mount"
@@ -261,12 +260,6 @@ func CreateConfigToOCISpec(config *CreateConfig) (*spec.Spec, error) { //nolint
 		addedResources = true
 	}
 
-	if config.Systemd && (strings.HasSuffix(config.Command[0], "init") ||
-		strings.HasSuffix(config.Command[0], "systemd")) {
-		if err := setupSystemd(config, &g); err != nil {
-			return nil, errors.Wrap(err, "failed to setup systemd")
-		}
-	}
 	for _, i := range config.Tmpfs {
 		// Default options if nothing passed
 		options := []string{"rw", "rprivate", "noexec", "nosuid", "nodev", "size=65536k"}
@@ -408,49 +401,6 @@ func blockAccessToKernelFilesystems(config *CreateConfig, g *generate.Generator)
 	}
 }
 
-// systemd expects to have /run, /run/lock and /tmp on tmpfs
-// It also expects to be able to write to /sys/fs/cgroup/systemd and /var/log/journal
-
-func setupSystemd(config *CreateConfig, g *generate.Generator) error {
-	mounts, err := config.GetVolumeMounts([]spec.Mount{})
-	if err != nil {
-		return err
-	}
-	options := []string{"rw", "rprivate", "noexec", "nosuid", "nodev"}
-	for _, dest := range []string{"/run", "/run/lock"} {
-		if libpod.MountExists(mounts, dest) {
-			continue
-		}
-		tmpfsMnt := spec.Mount{
-			Destination: dest,
-			Type:        "tmpfs",
-			Source:      "tmpfs",
-			Options:     append(options, "tmpcopyup", "size=65536k"),
-		}
-		g.AddMount(tmpfsMnt)
-	}
-	for _, dest := range []string{"/tmp", "/var/log/journal"} {
-		if libpod.MountExists(mounts, dest) {
-			continue
-		}
-		tmpfsMnt := spec.Mount{
-			Destination: dest,
-			Type:        "tmpfs",
-			Source:      "tmpfs",
-			Options:     append(options, "tmpcopyup"),
-		}
-		g.AddMount(tmpfsMnt)
-	}
-	tmpfsMnt := spec.Mount{
-		Destination: "/sys/fs/cgroup/systemd",
-		Type:        "tmpfs",
-		Source:      "tmpfs",
-		Options:     append(options, "size=65536k"),
-	}
-	g.AddMount(tmpfsMnt)
-	return nil
-}
-
 func addPidNS(config *CreateConfig, g *generate.Generator) error {
 	pidMode := config.PidMode
 	if IsNS(string(pidMode)) {