Automatically fetch & use the latest Maven 3 patch version for Docker builds/publish workflow (#204)

Author: msmygit

Dockerfile

@@ -17,13 +17,8 @@ RUN apt-get update && apt-get install -y openssh-server vim python3 --no-install
     rm -rf /var/lib/apt/lists/*  && \
     service ssh start
 
-COPY scripts/get-latest-maven-version.sh ./get-latest-maven-version.sh
-RUN chmod +x ./get-latest-maven-version.sh
-
 # Copy CDM jar & template files
-ARG MAVEN_VERSION=$(./get-latest-maven-version.sh)
 ARG USER_HOME_DIR="/root"
-ARG BASE_URL=https://dlcdn.apache.org/maven/maven-3/${MAVEN_VERSION}/binaries
 ENV MAVEN_HOME /usr/share/maven
 ENV MAVEN_CONFIG "$USER_HOME_DIR/.m2"
 COPY ./src /assets/src
@@ -32,8 +27,12 @@ COPY ./src/resources/cdm.properties /assets/
 COPY ./src/resources/cdm-detailed.properties /assets/
 COPY ./src/resources/partitions.csv /assets/
 COPY ./src/resources/primary_key_rows.csv /assets/
+COPY scripts/get-latest-maven-version.sh ./get-latest-maven-version.sh
 
-RUN mkdir -p /usr/share/maven /usr/share/maven/ref && \
+RUN chmod +x ./get-latest-maven-version.sh && \
+    export MAVEN_VERSION=$(./get-latest-maven-version.sh) && \
+    export BASE_URL=https://dlcdn.apache.org/maven/maven-3/${MAVEN_VERSION}/binaries && \
+    mkdir -p /usr/share/maven /usr/share/maven/ref && \
     curl -fsSL -o /tmp/apache-maven.tar.gz ${BASE_URL}/apache-maven-${MAVEN_VERSION}-bin.tar.gz && \
     tar -xzf /tmp/apache-maven.tar.gz -C /usr/share/maven --strip-components=1 && \
     rm -f /tmp/apache-maven.tar.gz && \