feat(RELEASE): allow overriding build.sh

* add `ARG` for `RELEASE_URL`
* make `build.sh` prepare `.tags` even if tag exists
* add outputs to be used by github workflows

Dockerfile

@@ -7,11 +7,12 @@ RUN  apk update \
     && update-ca-certificates    
 
 # Download TileBoard
-RUN wget -q -O release.zip "%RELEASE_URL%" \
+ARG RELEASE_URL
+RUN wget -q -O release.zip "${RELEASE_URL:-%RELEASE_URL%}" \
     && unzip release.zip -d /tileboard/ \
     && rm release.zip
 
 # Start Server
 WORKDIR /tileboard
 EXPOSE  8000
-ENTRYPOINT python3 -m http.server
+ENTRYPOINT python3 -m http.server

build.sh

@@ -32,21 +32,27 @@ echo "Docker repository: $docker_repo."
 
 LATEST_RELEASE=`getVersionFromLatestRelease $source_repo`
 echo "Latest release is: $LATEST_RELEASE."
+echo "::set-output name=latest_release::$LATEST_RELEASE"
+
+SEMVER=( ${LATEST_RELEASE//./ } )
+MAJOR=${SEMVER[0]}
+MINOR=${SEMVER[0]}.${SEMVER[1]}
+PATCH=$LATEST_RELEASE
+echo "::set-output name=major::$MAJOR"
+echo "::set-output name=minor::$MINOR"
+echo "::set-output name=patch::$PATCH"
+
+echo "latest,$MAJOR,$MINOR,$PATCH" > .tags
+echo "::set-output name=tags::$(cat .tags)"
+
+RELEASE_URL=`getDownloadUrl`
+echo "URL of release is: $RELEASE_URL."
+echo "::set-output name=release_url::$RELEASE_URL"
 
 if docker_tag_exists $docker_repo $LATEST_RELEASE; then
     echo "Nothing to do. Latest release tag already exists."
     exit 78 # drone.io exit code to stop but success the pipeline
 fi
 
-SEMVER=( ${LATEST_RELEASE//./ } )
-MAJOR=${SEMVER[0]}
-MINOR=${SEMVER[0]}.${SEMVER[1]}
-PATCH=$LATEST_RELEASE
-
-echo "latest,$MAJOR,$MINOR,$PATCH" > .tags
-
-RELEASE_URL=`getDownloadUrl`
-echo "URL of release is: $RELEASE_URL."
-
 echo "Writing release URL into Dockerfile..."
 sed -i "s|%RELEASE_URL%|$RELEASE_URL|g" ./Dockerfile