Merge pull request #1379 from awh/issues/1369-weave-dns-add-remove-optional-ip

LGTM.  Fixes #1369

site/weavedns.md

@@ -148,18 +148,20 @@ If you want to give the container a name in DNS *other* than its
 hostname, you can register it using the `dns-add` command. For example:
 
 ```bash
-$ C=$(docker run -e WEAVE_CIDR=10.2.1.27/24 -ti ubuntu)
-$ weave dns-add 10.2.1.27 $C -h pingme2.weave.local
+$ C=$(docker run -ti ubuntu)
+$ weave dns-add $C -h pingme2.weave.local
 ```
 
 You can also use `dns-add` to add the container's configured hostname
-and domain, simply by omitting `-h <fqdn>`.
+and domain simply by omitting `-h <fqdn>`, or specify additional IP
+addresses to be registered against the container's hostname e.g.
+`weave dns-add 10.2.1.27 $C`.
 
 The inverse operation can be carried out using the `dns-remove`
 command:
 
 ```bash
-$ weave dns-remove 10.2.1.27 $C
+$ weave dns-remove $C
 ```
 
 ## <a name="resolve-weavedns-entries-from-host"></a>Resolve weaveDNS entries from host

test/240_dns_add_name_test.sh

@@ -20,7 +20,7 @@ weave_on $HOST1 dns-add $C2 c2 -h $NAME2
 assert_dns_record $HOST1 c1 $NAME2 $C2
 
 weave_on $HOST1 dns-add $C1 c1 -h $NAME1
-weave_on $HOST1 dns-add $C1 c1 -h $NAME3
+weave_on $HOST1 dns-add c1 -h $NAME3
 
 assert_dns_a_record $HOST1 c1 $NAME1 $C1
 assert_dns_a_record $HOST1 c1 $NAME3 $C1
@@ -30,4 +30,8 @@ weave_on $HOST1 dns-remove $C1 c1 -h $NAME1
 assert_no_dns_record $HOST1 c1 $NAME1
 assert_dns_a_record $HOST1 c1 $NAME3 $C1
 
+weave_on $HOST1 dns-remove c1 -h $NAME3
+
+assert_no_dns_record $HOST1 c1 $NAME3
+
 end_suite

weave

@@ -67,8 +67,8 @@ weave run           [--with-dns | --without-dns] [<addr> ...]
 weave start         [<addr> ...] <container_id>
 weave attach        [<addr> ...] <container_id>
 weave detach        [<addr> ...] <container_id>
-weave dns-add       <ip_address> [<ip_address> ...] <container_id> [-h <fqdn>]
-weave dns-remove    <ip_address> [<ip_address> ...] <container_id> [-h <fqdn>]
+weave dns-add       [<ip_address> ...] <container_id> [-h <fqdn>]
+weave dns-remove    [<ip_address> ...] <container_id> [-h <fqdn>]
 weave dns-lookup    <unqualified_name>
 weave expose        [<addr> ...] [-h <fqdn>]
 weave hide          [<addr> ...]
@@ -735,6 +735,12 @@ echo_addresses() {
     echo $1 $2 $3
 }
 
+echo_ips() {
+    for CIDR in $3; do
+        echo ${3%/*}
+    done
+}
+
 peer_args() {
   res=''
   sep=''
@@ -1502,9 +1508,12 @@ case "$COMMAND" in
     dns-add)
         collect_ip_args "$@"
         shift $IP_COUNT
-        [ $IP_COUNT -gt 0 -a \( $# -eq 1 -o \( $# -eq 3 -a "$2" = "-h" \) \) ] || usage
+        [ $# -eq 1 -o \( $# -eq 3 -a "$2" = "-h" \) ] || usage
         check_running $CONTAINER_NAME
         CONTAINER=$(container_id $1)
+        if [ $IP_COUNT -eq 0 ] ; then
+            IP_ARGS=$(with_container_addresses echo_ips $CONTAINER)
+        fi
         if [ $# -eq 1 ] ; then
             with_container_fqdn $CONTAINER put_dns_fqdn $IP_ARGS
         else
@@ -1514,9 +1523,12 @@ case "$COMMAND" in
     dns-remove)
         collect_ip_args "$@"
         shift $IP_COUNT
-        [ $IP_COUNT -gt 0 -a \( $# -eq 1 -o \( $# -eq 3 -a "$2" = "-h" \) \) ] || usage
+        [ $# -eq 1 -o \( $# -eq 3 -a "$2" = "-h" \) ] || usage
         check_running $CONTAINER_NAME
         CONTAINER=$(container_id $1)
+        if [ $IP_COUNT -eq 0 ] ; then
+            IP_ARGS=$(with_container_addresses echo_ips $CONTAINER)
+        fi
         if [ $# -eq 1 ] ; then
             delete_dns $CONTAINER $IP_ARGS
         else