Merge pull request #75 from reactiveops/ej/docker-compatibility

simple idea to make rok8s-scripts compatible with docker older and ne…

bin/docker-push

@@ -31,7 +31,18 @@ then
   exit 1
 fi
 
-docker tag -f "${DOCKERTAG}:latest" "${EXTERNAL_REGISTRY_BASE_DOMAIN}/${REPOSITORY_NAME}:${CI_REF}"
+DOCKER_TAG_COM="docker tag"
+version=$(docker version | grep -e Version | head -n 1 | awk '{ print $2 }')
+major=$(echo "${version}" | awk -F. '{ print $1 }')
+minor=$(echo "${version}" | awk -F. '{ print $2 }')
+
+if [[ "${minor#0}" -le 9 && "${major}" -eq 1 ]] || [ "${major}" -eq 0 ]
+then
+  DOCKER_TAG_COM="${DOCKER_TAG_COM} -f "
+fi
+
+$DOCKER_TAG_COM "${DOCKERTAG}:latest" "${EXTERNAL_REGISTRY_BASE_DOMAIN}/${REPOSITORY_NAME}:${CI_REF}"
+
 if [ $? -ne 0 ]
 then
   echo "Unable to tag image, aborting"