try to switch to drone version on non-tagged

Dockerfile

@@ -12,8 +12,12 @@ ARG TRAVIS_PULL_REQUEST
 ARG TRAVIS_PULL_REQUEST_SHA
 ARG TRAVIS_REPO_SLUG
 ARG TRAVIS_TAG
+
+ARG DRONE
 ARG DRONE_TAG
 ARG DRONE_COMMIT
+ARG DRONE_BRANCH
+ARG DRONE_PULL_REQUEST
 
 WORKDIR /go/src/github.com/umputun/remark/backend
 
@@ -32,13 +36,13 @@ RUN if [ -z "$COVERALLS_TOKEN" ] ; then \
     echo coverall not enabled ; \
     else goveralls -coverprofile=.cover/cover.out -service=travis-ci -repotoken $COVERALLS_TOKEN || echo "coverall failed!"; fi
 
-# get revision from git. if DRONE_TAG presented use DRONE_* git env to make version
+# get revision from git. if DRONE presented use DRONE_* git env to make version
 RUN \
     cd /go/src/github.com/umputun/remark && version=$(/script/git-rev.sh) && cd backend \
     echo "git version=$version" && \  
-    if [ -z "$DRONE_TAG" ] ; then \
+    if [ -z "$DRONE" ] ; then \
     echo "runs outside of drone" ; \
-    else version=${DRONE_TAG}-${DRONE_COMMIT:0:7}-$(date +%Y%m%d-%H:%M:%S); fi && \
+    else version=${DRONE_TAG}${DRONE_BRANCH}${DRONE_PULL_REQUEST}-${DRONE_COMMIT:0:7}-$(date +%Y%m%d-%H:%M:%S); fi && \
     echo "final version=$version" && \  
     go build -o remark -ldflags "-X main.revision=${version} -s -w" ./app