report the proxy version instead of weaveexec version

That way we no longer rely on the weavexec image version tag, which
may not always be present. Since the proxy is embedded in the
weaveexec image, this effectively versions the image.

Also report the *local* script version instead of the embedded script
version. There is no point in reporting the latter since it will
always match the weaveexec version.

Closes #1341.

weave

@@ -217,6 +217,11 @@ if [ "$1" = "--help" -o "$1" = "help" ] ; then
     # at the client end.
     usage_no_exit
     exit 0
+elif [ "$1" = "version" -a -z "$IS_LOCAL" ] ; then
+    # non-local "version" is special because we want to show the
+    # version of the script executed by the user rather than what is
+    # embedded in weaveexec.
+    echo "weave script $SCRIPT_VERSION"
 elif [ "$1" = "env" -a "$2" = "--restore" ] ; then
     # "env --restore" is special because we always want to process it
     # at the client end.
@@ -498,11 +503,7 @@ ask_version() {
                 echo "Unable to find $2 image." >&2
             fi
     fi
-    VERSION_COVERAGE_ARGS=""
-    if [ "$1" = "$CONTAINER_NAME" ] || [ "$1" == "$PROXY_CONTAINER_NAME"]  ; then
-        VERSION_COVERAGE_ARGS="$COVERAGE_ARGS"
-    fi
-    [ -n "$DOCKERIMAGE" ] && docker run --rm -e WEAVE_CIDR=none $DOCKERIMAGE $VERSION_COVERAGE_ARGS --version
+    [ -n "$DOCKERIMAGE" ] && docker run --rm -e WEAVE_CIDR=none $3 $DOCKERIMAGE $COVERAGE_ARGS --version
 }
 
 ######################################################################
@@ -1329,18 +1330,8 @@ case "$COMMAND" in
         ;;
     version)
         [ $# -eq 0 ] || usage
-        echo weave script $SCRIPT_VERSION
         ask_version $CONTAINER_NAME $IMAGE || true
-        if ! EXEC_IMAGE_ID=$(docker inspect --format='{{.Id}}' $EXEC_IMAGE 2>/dev/null) ; then
-            echo "Unable to find $EXEC_IMAGE image." >&2
-        else
-            EXEC_VERSION=$(docker images --no-trunc | grep $EXEC_IMAGE_ID | grep -v latest | tr -s ' ' | cut -d ' ' -f 2 | tr "\n" ' ')
-            if [ -n "$EXEC_VERSION" ] ; then
-                echo "weave exec $EXEC_VERSION"
-            else
-                echo "weave exec (unreleased version)"
-            fi
-        fi
+        ask_version $PROXY_CONTAINER_NAME $EXEC_IMAGE --entrypoint=/home/weave/weaveproxy || true
         ;;
     # intentionally undocumented since it assumes knowledge of weave
     # internals