Integrating systemd freeze functionality.

This pulls together #6061 and #6125

Docker-DCO-1.1-Signed-off-by: Chris Alfonso <calfonso@redhat.com> (github: calfonso)

daemon/container.go

@@ -538,6 +538,11 @@ func (container *Container) KillSig(sig int) error {
 	container.Lock()
 	defer container.Unlock()
 
+	// We could unpause the container for them rather than returning this error
+	if container.State.IsPaused() {
+		return fmt.Errorf("Container %s is paused. Unpause the container before stopping", container.ID)
+	}
+
 	if !container.State.IsRunning() {
 		return nil
 	}
@@ -594,11 +599,6 @@ func (container *Container) Stop(seconds int) error {
 		return nil
 	}
 
-	// We could unpause the container for them rather than returning this error
-	if container.State.IsPaused() {
-		return fmt.Errorf("Container %s is paused. Unpause the container before stopping", container.ID)
-	}
-
 	// 1. Send a SIGTERM
 	if err := container.KillSig(15); err != nil {
 		log.Print("Failed to send SIGTERM to the process, force killing")

daemon/daemon.go

@@ -1015,8 +1015,7 @@ func (daemon *Daemon) Run(c *Container, pipes *execdriver.Pipes, startCallback e
 }
 
 func (daemon *Daemon) Pause(c *Container) error {
-	err := daemon.execDriver.Pause(c.command)
-	if err != nil {
+	if err := daemon.execDriver.Pause(c.command); err != nil {
 		return err
 	}
 	c.State.SetPaused()
@@ -1024,8 +1023,7 @@ func (daemon *Daemon) Pause(c *Container) error {
 }
 
 func (daemon *Daemon) Unpause(c *Container) error {
-	err := daemon.execDriver.Unpause(c.command)
-	if err != nil {
+	if err := daemon.execDriver.Unpause(c.command); err != nil {
 		return err
 	}
 	c.State.SetUnpaused()

daemon/execdriver/native/configuration/parse.go

@@ -27,7 +27,6 @@ var actions = map[string]Action{
 	"cgroups.memory_reservation": memoryReservation, // set the memory reservation
 	"cgroups.memory_swap":        memorySwap,        // set the memory swap limit
 	"cgroups.cpuset.cpus":        cpusetCpus,        // set the cpus used
-	"cgroups.freezer":            freezer,           // set the frozen/thaw state
 
 	"systemd.slice": systemdSlice, // set parent Slice used for systemd unit
 
@@ -36,16 +35,6 @@ var actions = map[string]Action{
 	"fs.readonly": readonlyFs, // make the rootfs of the container read only
 }
 
-func freezer(container *libcontainer.Container, context interface{}, value string) error {
-	if container.Cgroups == nil {
-		return fmt.Errorf("cannot set cgroups when they are disabled")
-	}
-
-	container.Cgroups.Freezer = value
-
-	return nil
-}
-
 func cpusetCpus(container *libcontainer.Container, context interface{}, value string) error {
 	if container.Cgroups == nil {
 		return fmt.Errorf("cannot set cgroups when they are disabled")

daemon/execdriver/native/driver.go

@@ -147,28 +147,26 @@ func (d *driver) Kill(p *execdriver.Command, sig int) error {
 
 func (d *driver) Pause(c *execdriver.Command) error {
 	active := d.activeContainers[c.ID]
-	active.container.Cgroups.Freezer = "FROZEN"
-	pid := c.Process.Pid
-
-	if systemd.UseSystemd() {
-		_, err := systemd.Apply(active.container.Cgroups, pid)
-		return err
+	if active == nil {
+		return fmt.Errorf("active container for %s does not exist", c.ID)
 	}
-	_, err := fs.Apply(active.container.Cgroups, pid)
-	return err
+	active.container.Cgroups.Freezer = "FROZEN"
+	if systemd.UseSystemd() {
+		return systemd.Freeze(active.container.Cgroups, active.container.Cgroups.Freezer)
+	}
+	return fs.Freeze(active.container.Cgroups, active.container.Cgroups.Freezer)
 }
 
 func (d *driver) Unpause(c *execdriver.Command) error {
 	active := d.activeContainers[c.ID]
-	active.container.Cgroups.Freezer = "THAWED"
-	pid := c.Process.Pid
-
-	if systemd.UseSystemd() {
-		_, err := systemd.Apply(active.container.Cgroups, pid)
-		return err
+	if active == nil {
+		return fmt.Errorf("active container for %s does not exist", c.ID)
 	}
-	_, err := fs.Apply(active.container.Cgroups, pid)
-	return err
+	active.container.Cgroups.Freezer = "THAWED"
+	if systemd.UseSystemd() {
+		return systemd.Freeze(active.container.Cgroups, active.container.Cgroups.Freezer)
+	}
+	return fs.Freeze(active.container.Cgroups, active.container.Cgroups.Freezer)
 }
 
 func (d *driver) Terminate(p *execdriver.Command) error {