Add versioning and gitflow support

Dockerfile

@@ -17,25 +17,21 @@ RUN add-apt-repository \
    $(lsb_release -cs) \
    stable"
 
-# This query the list of available docker version
-# RUN apt-get update && apt-cache madison docker-ce
+RUN apt-get update && echo "List of available Docker versions ( we are using ${DOCKER_VERSION} )" && apt-cache madison docker-ce
 
-RUN apt-get update && apt-get install -y docker-ce-cli=${DOCKER_VERSION}
+RUN apt-get install -y docker-ce-cli=${DOCKER_VERSION}
 
 RUN curl   -o /tmp/cern-root-ca-2.crt "https://cafiles.cern.ch/cafiles/certificates/CERN%20Root%20Certification%20Authority%202.crt" && \
       curl -o /tmp/cern-ca.crt        "https://cafiles.cern.ch/cafiles/certificates/CERN%20Certification%20Authority.crt" && \
-      curl -o /tmp/cern-ca-1.crt      "https://cafiles.cern.ch/cafiles/certificates/CERN%20Certification%20Authority(1).crt"
-
-RUN keytool -noprompt -import -keystore $JAVA_HOME/jre/lib/security/cacerts -storepass changeit -alias CERN_ROOT_CA_2 -file "/tmp/cern-root-ca-2.crt" && \
-    keytool -noprompt -import -keystore $JAVA_HOME/jre/lib/security/cacerts -storepass changeit -alias CERN_CA -file "/tmp/cern-ca.crt" && \
-    keytool -noprompt -import -keystore $JAVA_HOME/jre/lib/security/cacerts -storepass changeit -alias CERN_CA_1 -file "/tmp/cern-ca-1.crt"
+      curl -o /tmp/cern-ca-1.crt      "https://cafiles.cern.ch/cafiles/certificates/CERN%20Certification%20Authority(1).crt" && \
+      keytool -noprompt -import -keystore $JAVA_HOME/jre/lib/security/cacerts -storepass changeit -alias CERN_ROOT_CA_2 -file "/tmp/cern-root-ca-2.crt" && \
+      keytool -noprompt -import -keystore $JAVA_HOME/jre/lib/security/cacerts -storepass changeit -alias CERN_CA -file "/tmp/cern-ca.crt" && \
+      keytool -noprompt -import -keystore $JAVA_HOME/jre/lib/security/cacerts -storepass changeit -alias CERN_CA_1 -file "/tmp/cern-ca-1.crt" && \
+      rm /tmp/*.crt
 
 RUN mkdir -p /opt
 
 ADD src/main/java/SSLPoke.java /opt
 RUN cd /opt && javac SSLPoke.java && java SSLPoke repository.cern.ch 443
 
-
-# RUN rm -f /tmp/*.crt
-
-# TODO : Clean up the APT cache too
\ No newline at end of file
+RUN rm -rf /var/lib/apt/lists/

README.md

 # Maven Docker in Docker
 
-An Alpine Linux + Docker + Maven image to perform Docker-in-Docker builds on CERN Gitlab.
\ No newline at end of file
+An official Maven Debian + Docker + CERN CA certificates image to perform Docker-in-Docker builds on CERN Gitlab.
+
+The image build is provided :
+
+* As a baseline image, with default build arguments hard-coded in the provided Dockerfile. Consult the Dockerfile to know the current configuration.
+* As a Maven-enabled image with support for branching, parameters and releases (thank to the maven-dockerfile-plugin).
+
+*Important Note :* The Gitlab CI only performs a baseline build in the master branch. The baseline is used to rebuild all other images so pick a sensible default.
+
+# How to update the baseline
+
+Simply update the Dockerfile build arguments' default values, and commit to the master branch. NOTE : The baseline is used to rebuild all other images so pick a sensible default.
+
+# How to provide alternate images
+
+Using gitflow, you can create a new *support* branch, it will automatically be picked up and deployed as a new docker image.
+To name your support branch, please follow the convention <maven-version>-<docker-client-version>-<jdk-version> (with or without the SNAPSHOT suffix).
+
+For instance :
+
+* 3.5.3-19.0.3-jdk8
+* 3.6.0-19.0.3.2-jdk11

pom.xml

@@ -4,10 +4,14 @@
 
   <groupId>cern.ics.swinfra</groupId>
   <artifactId>mvn-dind</artifactId>
-  <version>1.0-SNAPSHOT</version>
+  <version>3.5.3-19.0.3-jdk8</version>
 
   <description>A Maven + Docker DIND image to build images.</description>
 
+  <scm>
+     <developerConnection>scm:git:ssh://git@gitlab.cern.ch/industrial-controls/sw-infra/mvn-dind.git</developerConnection>
+    </scm>
+  
   <properties>
     <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
   </properties>
@@ -22,6 +26,20 @@
            <skip>true</skip>
         </configuration>
       </plugin>
+      <plugin>
+		<groupId>com.e-gineering</groupId>
+		<artifactId>gitflow-helper-maven-plugin</artifactId>
+		<version>2.2.0</version>
+		<executions>
+			<execution>
+				<goals>
+					<goal>enforce-versions</goal>
+					<goal>tag-master</goal>
+				</goals>
+			</execution>
+		</executions>
+      </plugin>
+      
       <plugin>
 		<groupId>com.spotify</groupId>
 		<artifactId>dockerfile-maven-plugin</artifactId>