Refactor common code in attach/detach

weaver/weave

@@ -120,20 +120,30 @@ container_netns_preamble() {
     ln -s /proc/$NSPID/ns/net /var/run/netns/$NSPID
     LOCAL_IFNAME="v${CONTAINER_IFNAME}pl${NSPID}"
     GUEST_IFNAME="v${CONTAINER_IFNAME}pg${NSPID}"
+    EXITCODE=1
+    IP_TMPFILE=/tmp/weave_ip_output_$$
+    rm -f $IP_TMPFILE
 
     return 0
 }
 
-container_netns_cleanup() {
+container_netns_postamble() {
+    if [ "$EXITCODE" -ne 0 ] ; then
+        if ! ps -p $DOCKERPID >/dev/null 2>&1 ; then
+            echo "Container $1 died" >&2
+        else
+            echo "Failure during network configuration for container $1:" >&2
+            cat $IP_TMPFILE >&2
+        fi
+    fi
+
+    rm -f $IP_TMPFILE
     rm -f /var/run/netns/$NSPID
 }
 
 # Parameters are container ID, CIDR address
 configure_container_networking() {
     container_netns_preamble $1
-    EXITCODE=1
-    IP_TMPFILE=/tmp/weave_ip_output_$$
-    rm -f $IP_TMPFILE
 
     # If veth name already exists then assume we set it up already;
     # just add the IP address, if it's not already there
@@ -161,17 +171,7 @@ configure_container_networking() {
         fi
     fi
 
-    if [ "$EXITCODE" -ne 0 ] ; then
-        if ! ps -p $DOCKERPID >/dev/null 2>&1 ; then
-            echo "Container $1 died" >&2
-        else
-            echo "Failure during network configuration for container $1:" >&2
-            cat $IP_TMPFILE >&2
-        fi
-    fi
-
-    rm -f $IP_TMPFILE
-    container_netns_cleanup
+    container_netns_postamble $1
 
     return $EXITCODE
 }
@@ -180,9 +180,6 @@ configure_container_networking() {
 detach() {
     container_netns_preamble $1
 
-    EXITCODE=1
-    IP_TMPFILE=/tmp/weave_ip_output_$$
-    rm -f $IP_TMPFILE
     if (ip netns exec $NSPID ip addr list dev $CONTAINER_IFNAME | grep -qF $2) 2>$IP_TMPFILE ; then
         if ip netns exec $NSPID ip addr del $2 dev $CONTAINER_IFNAME 2>$IP_TMPFILE ; then
             # if no inet addresses remain then delete the veth
@@ -198,17 +195,7 @@ detach() {
         EXITCODE=0
     fi
 
-    if [ "$EXITCODE" -ne 0 ] ; then
-        if ! ps -p $DOCKERPID >/dev/null 2>&1 ; then
-            echo "Container $1 died" >&2
-        else
-            echo "Failure while detaching address $2 from container $1" >&2
-            cat $IP_TMPFILE >&2
-        fi
-    fi
-
-    rm -f $IP_TMPFILE
-    container_netns_cleanup
+    container_netns_postamble $1
     return $EXITCODE
 }