Made starting swarm client optional

Dockerfile

@@ -26,11 +26,12 @@ RUN mkdir -p /var/run/sshd
 ENV JENKINS_HOME /var/lib/jenkins
 ADD init.sh /init.sh
 ADD install /tmp/install
-RUN for INSTALLER in `ls /tmp/install/0*.sh | sort -n`; do /bin/bash $INSTALLER; done && rm -rf /tmp/install
+RUN for INSTALLER in `ls /tmp/install/*.sh | sort -n`; do /bin/bash $INSTALLER; done && rm -rf /tmp/install
 
 # Start Jenkins Slave
 ENV SWARM_USER jenkins
 ENV SWARM_PASSWORD pC4oLhceTFo4fzzVugzZ
+ENV SWARM_EXECUTORS 1
 EXPOSE 22
 VOLUME ["/var/lib/jenkins"]
 CMD ["/bin/bash", "/init.sh"]
\ No newline at end of file

init.sh

@@ -2,13 +2,15 @@
 
 set -e # Exit on errors
 
-# Check if required parameters are set
-: ${SWARM_MASTER:?"Please use 'docker run -e SWARM_MASTER=...' to run this container!"}
-
-echo "-> Starting Jenkins Slave ..."
+if [ ${SWARM_MASTER:+x} ]; then
+    echo "-> Starting SSH Daemon & Swarm Client ..."
     echo "   - SWARM_MASTER:    $SWARM_MASTER"
     echo "   - SWARM_USER:      $SWARM_USER"
     echo "   - SWARM_PASSWORD:  $SWARM_PASSWORD"
-
+    echo "   - SWARM_EXECUTORS: $SWARM_EXECUTORS"
     /usr/sbin/sshd
-su -l $JENKINS_USER --shell=/bin/bash -c "java -jar /var/lib/jenkins/tools/swarm/swarm-client.jar -master $SWARM_MASTER -username $SWARM_USER -password $SWARM_PASSWORD"
+    su -l $JENKINS_USER --shell=/bin/bash -c "java -jar /var/lib/jenkins/tools/swarm/swarm-client.jar -executors $SWARM_EXECUTORS -master $SWARM_MASTER -username $SWARM_USER -password $SWARM_PASSWORD"
+else
+    echo "-> Starting SSH Daemon ..."
+    /usr/sbin/sshd -e -D
+fi