Merge pull request #1901 from weaveworks/1897-weaveutil-plugin-network

move plugin network creation/removal into weaveutil

prog/plugin/main.go

@@ -5,12 +5,8 @@ import (
 	"fmt"
 	"net"
 	"os"
-	"os/signal"
-	"strings"
-	"syscall"
 
 	"github.com/docker/libnetwork/ipamapi"
-	go_docker "github.com/fsouza/go-dockerclient"
 	. "github.com/weaveworks/weave/common"
 	"github.com/weaveworks/weave/common/docker"
 	ipamplugin "github.com/weaveworks/weave/plugin/ipam"
@@ -27,9 +23,7 @@ func main() {
 		nameserver       string
 		meshAddress      string
 		logLevel         string
-		meshNetworkName  string
 		noMulticastRoute bool
-		removeNetwork    bool
 	)
 
 	flag.BoolVar(&justVersion, "version", false, "print version and exit")
@@ -37,9 +31,7 @@ func main() {
 	flag.StringVar(&address, "socket", "/run/docker/plugins/weave.sock", "socket on which to listen")
 	flag.StringVar(&nameserver, "nameserver", "", "nameserver to provide to containers")
 	flag.StringVar(&meshAddress, "meshsocket", "/run/docker/plugins/weavemesh.sock", "socket on which to listen in mesh mode")
-	flag.StringVar(&meshNetworkName, "mesh-network-name", "weave", "network name to create in mesh mode")
 	flag.BoolVar(&noMulticastRoute, "no-multicast-route", false, "do not add a multicast route to network endpoints")
-	flag.BoolVar(&removeNetwork, "remove-network", false, "remove mesh network and exit")
 
 	flag.Parse()
 
@@ -56,16 +48,6 @@ func main() {
 		Log.Fatalf("unable to connect to docker: %s", err)
 	}
 
-	if removeNetwork {
-		if _, err = dockerClient.Client.NetworkInfo(meshNetworkName); err == nil {
-			err = dockerClient.Client.RemoveNetwork(meshNetworkName)
-			if err != nil {
-				Log.Fatalf("unable to remove network: %s", err)
-			}
-		}
-		os.Exit(0)
-	}
-
 	Log.Println("Weave plugin", version, "Command line options:", os.Args[1:])
 	Log.Info(dockerClient.Info())
 
@@ -86,26 +68,12 @@ func main() {
 		defer meshListener.Close()
 	}
 
-	if meshNetworkName != "" {
-		createNetwork(dockerClient, meshNetworkName, meshAddress)
-	}
-
-	sigChan := make(chan os.Signal, 1)
-	signal.Notify(sigChan, os.Interrupt, os.Kill, syscall.SIGTERM)
-
-	select {
-	case sig := <-sigChan:
-		Log.Debugf("Caught signal %s; shutting down", sig)
-		if err := dockerClient.Client.RemoveNetwork(meshNetworkName); err != nil {
-			Log.Fatal(err)
-		}
-	case err := <-endChan:
-		if err != nil {
-			Log.Errorf("Error from listener: %s", err)
-			globalListener.Close()
-			meshListener.Close()
-			os.Exit(1)
-		}
+	err = <-endChan
+	if err != nil {
+		Log.Errorf("Error from listener: %s", err)
+		globalListener.Close()
+		meshListener.Close()
+		os.Exit(1)
 	}
 }
 
@@ -140,24 +108,3 @@ func listenAndServe(dockerClient *docker.Client, address, nameserver string, noM
 
 	return listener, nil
 }
-
-func createNetwork(dockerClient *docker.Client, networkName, address string) {
-	if _, err := dockerClient.Client.NetworkInfo(networkName); err == nil {
-		Log.Printf("Docker network '%s' already exists", networkName)
-	} else if _, ok := err.(*go_docker.NoSuchNetwork); ok {
-		driverName := strings.TrimSuffix(address, ".sock")
-		if i := strings.LastIndex(driverName, "/"); i >= 0 {
-			driverName = driverName[i+1:]
-		}
-		options := go_docker.CreateNetworkOptions{
-			Name:           networkName,
-			CheckDuplicate: true,
-			Driver:         driverName,
-			IPAM:           go_docker.IPAMOptions{Driver: driverName},
-		}
-		_, err := dockerClient.Client.CreateNetwork(options)
-		if err != nil {
-			Log.Fatalf("Error creating network: %s", err)
-		}
-	}
-}

prog/weaveutil/main.go

@@ -16,6 +16,8 @@ func init() {
 		"create-datapath":        createDatapath,
 		"delete-datapath":        deleteDatapath,
 		"add-datapath-interface": addDatapathInterface,
+		"create-plugin-network":  createPluginNetwork,
+		"remove-plugin-network":  removePluginNetwork,
 	}
 }
 

prog/weaveutil/plugin_network.go

@@ -0,0 +1,67 @@
+/* various weave docker network plugin operations */
+package main
+
+import (
+	"fmt"
+
+	"github.com/fsouza/go-dockerclient"
+)
+
+func createPluginNetwork(args []string) error {
+	if len(args) != 2 {
+		cmdUsage("create-plugin-network", "<network-name> <driver-name>")
+	}
+	networkName := args[0]
+	driverName := args[1]
+	d, err := newDockerClient()
+	if err != nil {
+		return err
+	}
+	_, err = d.CreateNetwork(
+		docker.CreateNetworkOptions{
+			Name:           networkName,
+			CheckDuplicate: true,
+			Driver:         driverName,
+			IPAM:           docker.IPAMOptions{Driver: driverName},
+		})
+	if err != docker.ErrNetworkAlreadyExists && err != nil {
+		// Despite appearances to the contrary, CreateNetwork does
+		// sometimes(always?) *not* return ErrNetworkAlreadyExists
+		// when the network already exists. Hence we need to check for
+		// this explicitly.
+		if _, err2 := d.NetworkInfo(networkName); err2 != nil {
+			return fmt.Errorf("unable to create network: %s", err)
+		}
+	}
+	return nil
+}
+
+func removePluginNetwork(args []string) error {
+	if len(args) != 1 {
+		cmdUsage("remove-plugin-network", "<network-name>")
+	}
+	networkName := args[0]
+	d, err := newDockerClient()
+	if err != nil {
+		return err
+	}
+	err = d.RemoveNetwork(networkName)
+	if _, ok := err.(*docker.NoSuchNetwork); !ok && err != nil {
+		return fmt.Errorf("unable to remove network: %s", err)
+	}
+	return nil
+}
+
+func newDockerClient() (*docker.Client, error) {
+	// API 1.21 is the first version that supports docker network
+	// commands
+	c, err := docker.NewVersionedClientFromEnv("1.21")
+	if err != nil {
+		return nil, fmt.Errorf("unable to connect to docker: %s", err)
+	}
+	_, err = c.Version()
+	if err != nil {
+		return nil, fmt.Errorf("unable to connect to docker: %s", err)
+	}
+	return c, nil
+}

site/plugin.md

@@ -73,8 +73,6 @@ The plugin command-line arguments are:
 
  * `--log-level=debug|info|warning|error`, which tells the plugin
    how much information to emit for debugging.
- * `--mesh-network-name=<name>`: set it to blank to disable creation
-   of a default network, or a name of your own choice.
  * `--no-multicast-route`: stop weave adding a static IP route for
    multicast traffic on its interface
 

weave

@@ -448,7 +448,8 @@ util_op() {
     if command_exists weaveutil ; then
         weaveutil "$@"
     else
-        docker run --rm --privileged --net=host -v /proc:/hostproc -e PROCFS=/hostproc \
+        docker run --rm --privileged --net=host $(docker_sock_options) \
+            -v /proc:/hostproc -e PROCFS=/hostproc \
             --entrypoint=/usr/bin/weaveutil $EXEC_IMAGE "$@"
     fi
 }
@@ -1682,26 +1683,23 @@ launch_plugin_if_not_running() {
     # Any other kind of error code from check_not_running is a failure.
     [ $retval -gt 0 ] && return $retval
 
-    PLUGIN_CONTAINER=$(docker run --privileged -d --name=$PLUGIN_CONTAINER_NAME \
+    if ! PLUGIN_CONTAINER=$(docker run --privileged -d --name=$PLUGIN_CONTAINER_NAME \
         --restart=always \
         --net=host \
         $(docker_sock_options) \
         -v /run/docker/plugins:/run/docker/plugins \
-        $PLUGIN_IMAGE "$@")
+        $PLUGIN_IMAGE "$@") ; then
+        return 1
+    fi
+    util_op create-plugin-network weave weavemesh
 }
 
 plugin_disabled() {
     [ -n "$WEAVE_NO_PLUGIN" ] || ! check_docker_server_api_version 1.21
 }
 
-remove_plugin_network() {
-    docker run --rm --net=host \
-        -v /var/run/docker.sock:/var/run/docker.sock \
-        $PLUGIN_IMAGE --remove-network
-}
-
 stop_plugin() {
-    remove_plugin_network
+    util_op remove-plugin-network weave
     stop $PLUGIN_CONTAINER_NAME "Plugin"
 }
 
@@ -2137,7 +2135,7 @@ EOF
         ;;
     reset)
         [ $# -eq 0 ] || usage
-        plugin_disabled || remove_plugin_network || \
+        plugin_disabled || util_op remove-plugin-network weave || \
             echo "WARNING: docker may hang in this state; re-launch weave and remove attached containers before shutting down" >&2
         warn_if_stopping_proxy_in_env
         call_weave DELETE /peer >/dev/null 2>&1 || true