Add support for building docker image with specific Occlum branch

.github/workflows/build_and_push_docker_image.yml

@@ -29,6 +29,11 @@ jobs:
         id: get_version
         run: echo "RELEASE_VERSION=$(echo ${GITHUB_REF:10})" >> $GITHUB_ENV;
 
+      - name: Get branch name
+        # GITHUB_REF=refs/heads/branch-name
+        # ${GITHUB_REF##*/} == branch-name
+        run: echo "OCCLUM_BRANCH=$(echo ${GITHUB_REF##*/})" >> $GITHUB_ENV;
+
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v1
 
@@ -47,6 +52,7 @@ jobs:
           context: .
           file: ./tools/docker/Dockerfile.centos8.1
           platforms: linux/amd64
+          build-args: OCCLUM_BRANCH=${{ env.OCCLUM_BRANCH }}
           push: true
           tags: occlum/occlum:${{ env.RELEASE_VERSION }}-centos8.1
 
@@ -69,6 +75,11 @@ jobs:
         id: get_version
         run: echo "RELEASE_VERSION=$(echo ${GITHUB_REF:10})" >> $GITHUB_ENV;
 
+      - name: Get branch name
+        # GITHUB_REF=refs/heads/branch-name
+        # ${GITHUB_REF##*/} == branch-name
+        run: echo "OCCLUM_BRANCH=$(echo ${GITHUB_REF##*/})" >> $GITHUB_ENV;
+
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v1
 
@@ -87,5 +98,6 @@ jobs:
           context: .
           file: ./tools/docker/Dockerfile.ubuntu18.04
           platforms: linux/amd64
+          build-args: OCCLUM_BRANCH=${{ env.OCCLUM_BRANCH }}
           push: true
           tags: occlum/occlum:${{ env.RELEASE_VERSION }}-ubuntu18.04

tools/docker/Dockerfile.centos8.1

@@ -96,8 +96,9 @@ RUN cd java && ./install_dragonwell.sh && rm -rf /tmp/java
 ENV PATH="/opt/occlum/toolchains/jvm/bin:$PATH"
 
 # Install the latest version of Occlum
+ARG OCCLUM_BRANCH
 WORKDIR /root
-RUN git clone https://github.com/occlum/occlum.git && \
+RUN git clone -b $OCCLUM_BRANCH https://github.com/occlum/occlum && \
     cd occlum && \
     source /root/.bashrc && \
     make submodule && \

tools/docker/Dockerfile.ubuntu18.04

@@ -108,8 +108,9 @@ RUN cd java && ./install_dragonwell.sh && rm -rf /tmp/java
 ENV PATH="/opt/occlum/toolchains/jvm/bin:$PATH"
 
 # Install the latest version of Occlum
+ARG OCCLUM_BRANCH
 WORKDIR /root
-RUN git clone https://github.com/occlum/occlum && \
+RUN git clone -b $OCCLUM_BRANCH https://github.com/occlum/occlum && \
     cd occlum && \
     make submodule && \
     OCCLUM_RELEASE_BUILD=1 make && \

tools/docker/build_image.sh

@@ -34,6 +34,7 @@ if [[ ( "$#" < 2 ) ]] ; then
     report_error
 fi
 
+occlum_branch=master
 occlum_label=$1
 os_name=$2
 
@@ -46,4 +47,4 @@ function check_item_in_list() {
 check_item_in_list "$os_name" "ubuntu18.04 centos7.5 centos8.1" || report_error
 
 cd "$script_dir/.."
-docker build -f "$script_dir/Dockerfile.$os_name" -t "occlum/occlum:$occlum_label-$os_name" .
+docker build -f "$script_dir/Dockerfile.$os_name" -t "occlum/occlum:$occlum_label-$os_name" --build-arg OCCLUM_BRANCH=$occlum_branch .