Wire up enforce_docker_bridge_addr_assign_type

prog/weaveutil/bridge.go

@@ -43,3 +43,10 @@ func createBridge(args []string) error {
 	fmt.Println(bridgeType.String())
 	return err
 }
+
+func enforceAddrAssign(args []string) error {
+	if len(args) != 1 {
+		cmdUsage("enforce-bridge-addr-assign-type", "<bridge-name>")
+	}
+	return weavenet.EnforceAddrAssignType(args[0])
+}

prog/weaveutil/main.go

@@ -19,6 +19,7 @@ func init() {
 		"docker-tls-args":          dockerTLSArgs,
 		"create-bridge":            createBridge,
 		"detect-bridge-type":       detectBridgeType,
+		"enforce-addr-assign":      enforceAddrAssign,
 		"create-datapath":          createDatapath,
 		"delete-datapath":          deleteDatapath,
 		"add-datapath-interface":   addDatapathInterface,

weave

@@ -379,20 +379,6 @@ arp_update() {
     ! command_exists arping || $3 arping -U -q -I $1 -c 1 ${2%/*}
 }
 
-# Generate a MAC value from a stdin containing six space separated
-# 2-digit hexadecimal numbers.
-mac_from_hex() {
-    # In the first byte of the MAC, the 'multicast' bit should be
-    # clear and 'locally administered' bit should be set.  All other
-    # bits should be random.
-    read a b c d e f && printf "%02x:$b:$c:$d:$e:$f" $((0x$a & ~1 | 2))
-}
-
-# Generate a random MAC value
-random_mac() {
-    od -txC -An -N6 /dev/urandom | mac_from_hex
-}
-
 ######################################################################
 # weave and docker specific helpers
 ######################################################################
@@ -419,19 +405,7 @@ EOF
 }
 
 enforce_docker_bridge_addr_assign_type() {
-    if ! ADDR_ASSIGN_TYPE=$(cat /sys/class/net/$DOCKER_BRIDGE/addr_assign_type 2>/dev/null) ; then
-        echo "Could not determine address assignment type of $DOCKER_BRIDGE" >&2
-        return
-    fi
-    # From include/uapi/linux/netdevice.h
-    # #define NET_ADDR_PERM       0   /* address is permanent (default) */
-    # #define NET_ADDR_RANDOM     1   /* address is generated randomly */
-    # #define NET_ADDR_STOLEN     2   /* address is stolen from other device */
-    # #define NET_ADDR_SET        3   /* address is set using dev_set_mac_address() */
-    if [ $ADDR_ASSIGN_TYPE != 3 ] ; then
-        echo "Setting $DOCKER_BRIDGE MAC (mitigate https://github.com/docker/docker/issues/14908)" >&2
-        ip link set dev $DOCKER_BRIDGE address $(random_mac) || true
-    fi
+    util_op enforce-addr-assign "$DOCKER_BRIDGE" || true
 }
 
 # Detect the current bridge/datapath state. When invoked, the values of