Add version label to docker images

Closes exoframejs/exoframe#274

Author: yamalight

.travis.yml

@@ -24,10 +24,11 @@ after_success:
   - docker login -u $HUB_USER -p $HUB_PASS
   - export TAG=`if [ "$TRAVIS_BRANCH" == "master" ]; then echo "latest"; else echo $TRAVIS_BRANCH ; fi`
   - export DEBUG_TAG=`if [ "$TRAVIS_BRANCH" == "master" ]; then echo "debug_latest"; else echo "debug_$TRAVIS_BRANCH" ; fi`
-  - docker build --pull -t exoframe/server:$TAG .
+  - export VERSION=`node -pe "require('./package.json').version"`
+  - docker build --pull -t --label "version=$VERSION" exoframe/server:$TAG .
   - if [ -z "$TRAVIS_TAG" ]; then echo "No tag, skipping"; else docker tag exoframe/server:$TAG exoframe/server:$TRAVIS_TAG; fi
   # build debug docker image
-  - docker build --pull -f Dockerfile-debug -t exoframe/server:$DEBUG_TAG .
+  - docker build --pull -f Dockerfile-debug --label "version=$VERSION" -t exoframe/server:$DEBUG_TAG .
   # push all images to registry
   - docker push exoframe/server