Factor out ask_version and don't exit 1 if it fails

weave

@@ -387,6 +387,15 @@ uname -s -r | sed -n 's|^\([^ ]*\) \([0-9]\+\)\.\([0-9]\+\).*|\1 \2 \3|p' | {
     fi
 }
 
+ask_version() {
+    if ! DOCKERIMAGE=$(docker inspect --format='{{ .Image }}' $1 2>/dev/null) ; then
+            if ! DOCKERIMAGE=$(docker inspect --format='{{ .Id }}' $2 2>/dev/null) ; then
+                echo "Unable to find $2 image." >&2
+            fi
+    fi
+    [ -n "$DOCKERIMAGE" ] && docker run --rm $DOCKERIMAGE --version
+}
+
 if ! command_exists ip ; then
     echo "ERROR: ip utility is missing. Please install it." >&2
     exit 1
@@ -482,20 +491,8 @@ case "$COMMAND" in
     version)
         [ $# -eq 0 ] || usage
         echo weave script $SCRIPT_VERSION
-        if ! DOCKERIMAGE=$(docker inspect --format='{{ .Image }}' $CONTAINER_NAME 2>/dev/null) ; then
-            if ! DOCKERIMAGE=$(docker inspect --format='{{ .Id }}' $IMAGE 2>/dev/null) ; then
-                echo "Unable to find $IMAGE image." >&2
-                exit 1
-            fi
-        fi
-        docker run --rm $DOCKERIMAGE --version
-        if ! DOCKERIMAGE=$(docker inspect --format='{{ .Image }}' $DNS_CONTAINER_NAME 2>/dev/null) ; then
-            if ! DOCKERIMAGE=$(docker inspect --format='{{ .Id }}' $DNS_IMAGE 2>/dev/null) ; then
-                echo "Unable to find $DNS_IMAGE image." >&2
-                exit 1
-            fi
-        fi
-        docker run --rm $DOCKERIMAGE --version
+        ask_version $CONTAINER_NAME $IMAGE
+        ask_version $DNS_CONTAINER_NAME $DNS_IMAGE
         ;;
     run)
         [ $# -gt 0 ] || usage