libnetwork: Add garbage collection trigger

When the daemon is going down trigger immediate
garbage collection of libnetwork resources deleted
like namespace path since there will be no way to
remove them when the daemon restarts.

Signed-off-by: Jana Radhakrishnan <mrjana@docker.com>
Upstream-commit: c68e7f96f9636a9b2ab0c2c0dbf753161fa73fc2
Component: engine

components/engine/vendor/src/github.com/docker/libnetwork/Godeps/Godeps.json

@@ -79,7 +79,7 @@
 		},
 		{
 			"ImportPath": "github.com/vishvananda/netns",
-			"Rev": "008d17ae001344769b031375bdb38a86219154c6"
+			"Rev": "5478c060110032f972e86a1f844fdb9a2f008f2c"
 		}
 	]
 }

components/engine/vendor/src/github.com/docker/libnetwork/controller.go

@@ -76,6 +76,9 @@ type NetworkController interface {
 
 	// NetworkByID returns the Network which has the passed id. If not found, the error ErrNoSuchNetwork is returned.
 	NetworkByID(id string) (Network, error)
+
+	// GC triggers immediate garbage collection of resources which are garbage collected.
+	GC()
 }
 
 // NetworkWalker is a client provided function which will be used to walk the Networks.
@@ -299,3 +302,7 @@ func (c *controller) loadDriver(networkType string) (driverapi.Driver, error) {
 	}
 	return d, nil
 }
+
+func (c *controller) GC() {
+	sandbox.GC()
+}

components/engine/vendor/src/github.com/docker/libnetwork/sandbox/namespace_linux.go

@@ -24,6 +24,7 @@ var (
 	gpmLock          sync.Mutex
 	gpmWg            sync.WaitGroup
 	gpmCleanupPeriod = 60 * time.Second
+	gpmChan          = make(chan chan struct{})
 )
 
 // The networkNamespace type is the linux implementation of the Sandbox
@@ -55,7 +56,18 @@ func removeUnusedPaths() {
 	period := gpmCleanupPeriod
 	gpmLock.Unlock()
 
-	for range time.Tick(period) {
+	ticker := time.NewTicker(period)
+	for {
+		var (
+			gc   chan struct{}
+			gcOk bool
+		)
+
+		select {
+		case <-ticker.C:
+		case gc, gcOk = <-gpmChan:
+		}
+
 		gpmLock.Lock()
 		pathList := make([]string, 0, len(garbagePathMap))
 		for path := range garbagePathMap {
@@ -70,6 +82,9 @@ func removeUnusedPaths() {
 		}
 
 		gpmWg.Done()
+		if gcOk {
+			close(gc)
+		}
 	}
 }
 
@@ -85,6 +100,18 @@ func removeFromGarbagePaths(path string) {
 	gpmLock.Unlock()
 }
 
+// GC triggers garbage collection of namespace path right away
+// and waits for it.
+func GC() {
+	waitGC := make(chan struct{})
+
+	// Trigger GC now
+	gpmChan <- waitGC
+
+	// wait for gc to complete
+	<-waitGC
+}
+
 // GenerateKey generates a sandbox key based on the passed
 // container id.
 func GenerateKey(containerID string) string {

components/engine/vendor/src/github.com/docker/libnetwork/sandbox/sandbox_linux_test.go

@@ -144,9 +144,16 @@ func verifySandbox(t *testing.T, s Sandbox) {
 	}
 }
 
-func verifyCleanup(t *testing.T, s Sandbox) {
-	time.Sleep(time.Duration(gpmCleanupPeriod * 2))
+func verifyCleanup(t *testing.T, s Sandbox, wait bool) {
+	if wait {
+		time.Sleep(time.Duration(gpmCleanupPeriod * 2))
+	}
+
 	if _, err := os.Stat(s.Key()); err == nil {
-		t.Fatalf("The sandbox path %s is not getting cleanup event after twice the cleanup period", s.Key())
+		if wait {
+			t.Fatalf("The sandbox path %s is not getting cleaned up even after twice the cleanup period", s.Key())
+		} else {
+			t.Fatalf("The sandbox path %s is not cleaned up after running gc", s.Key())
+		}
 	}
 }

components/engine/vendor/src/github.com/docker/libnetwork/sandbox/sandbox_test.go

@@ -54,7 +54,7 @@ func TestSandboxCreate(t *testing.T) {
 
 	verifySandbox(t, s)
 	s.Destroy()
-	verifyCleanup(t, s)
+	verifyCleanup(t, s, true)
 }
 
 func TestSandboxCreateTwice(t *testing.T) {
@@ -77,6 +77,23 @@ func TestSandboxCreateTwice(t *testing.T) {
 	s.Destroy()
 }
 
+func TestSandboxGC(t *testing.T) {
+	key, err := newKey(t)
+	if err != nil {
+		t.Fatalf("Failed to obtain a key: %v", err)
+	}
+
+	s, err := NewSandbox(key, true)
+	if err != nil {
+		t.Fatalf("Failed to create a new sandbox: %v", err)
+	}
+
+	s.Destroy()
+
+	GC()
+	verifyCleanup(t, s, false)
+}
+
 func TestInterfaceEqual(t *testing.T) {
 	list := getInterfaceList()
 

components/engine/vendor/src/github.com/vishvananda/netns/netns.go

@@ -12,6 +12,7 @@ import (
 	"fmt"
 	"syscall"
 )
+
 // NsHandle is a handle to a network namespace. It can be cast directly
 // to an int and used as a file descriptor.
 type NsHandle int

components/engine/vendor/src/github.com/vishvananda/netns/netns_linux.go

@@ -1,3 +1,5 @@
+// +build linux
+
 package netns
 
 import (

components/engine/vendor/src/github.com/vishvananda/netns/netns_linux_386.go

@@ -1,3 +1,5 @@
+// +build linux,386
+
 package netns
 
 const (

components/engine/vendor/src/github.com/vishvananda/netns/netns_linux_amd64.go

@@ -1,3 +1,5 @@
+// +build linux,amd64
+
 package netns
 
 const (

components/engine/vendor/src/github.com/vishvananda/netns/netns_linux_arm.go

@@ -1,3 +1,5 @@
+// +build linux,arm
+
 package netns
 
 const (

components/engine/vendor/src/github.com/vishvananda/netns/netns_linux_ppc64le.go

@@ -0,0 +1,7 @@
+// +build linux,ppc64le
+
+package netns
+
+const (
+	SYS_SETNS = 350
+)

components/engine/vendor/src/github.com/vishvananda/netns/netns_unspecified.go

@@ -10,26 +10,26 @@ var (
 	ErrNotImplemented = errors.New("not implemented")
 )
 
-func Set(ns Namespace) (err error) {
+func Set(ns NsHandle) (err error) {
 	return ErrNotImplemented
 }
 
-func New() (ns Namespace, err error) {
+func New() (ns NsHandle, err error) {
 	return -1, ErrNotImplemented
 }
 
-func Get() (Namespace, error) {
+func Get() (NsHandle, error) {
 	return -1, ErrNotImplemented
 }
 
-func GetFromName(name string) (Namespace, error) {
+func GetFromName(name string) (NsHandle, error) {
 	return -1, ErrNotImplemented
 }
 
-func GetFromPid(pid int) (Namespace, error) {
+func GetFromPid(pid int) (NsHandle, error) {
 	return -1, ErrNotImplemented
 }
 
-func GetFromDocker(id string) (Namespace, error) {
+func GetFromDocker(id string) (NsHandle, error) {
 	return -1, ErrNotImplemented
 }