add kenkins user to docker group

Change-Id: I00530911e8b479f2792859853751e7ad008b7c3f

jenkins/Dockerfile

@@ -21,6 +21,12 @@ COPY sources.list /etc/apt/sources.list
 
 RUN apt-get update \
     && apt-get install -y git curl \
+    && apt-get install sudo -y --allow-unauthenticated \
+    && apt-get -y install apt-transport-https ca-certificates software-properties-common \
+    && curl -fsSL http://mirrors.aliyun.com/docker-ce/linux/ubuntu/gpg | apt-key add - \
+    && add-apt-repository "deb [arch=amd64] http://mirrors.aliyun.com/docker-ce/linux/ubuntu $(lsb_release -cs) stable" \
+    && apt-get -y update \
+    && apt-get -y install docker-ce \
     && rm -rf /var/lib/apt/lists/*
 
 ARG user=jenkins
@@ -37,7 +43,8 @@ ENV JENKINS_SLAVE_AGENT_PORT ${agent_port}
 # If you bind mount a volume from the host or a data container,
 # ensure you use the same uid
 RUN groupadd -g ${gid} ${group} \
-    && useradd -d "$JENKINS_HOME" -u ${uid} -g ${gid} -m -s /bin/bash ${user}
+    && useradd -d "$JENKINS_HOME" -u ${uid} -g ${gid} -m -s /bin/bash ${user} \
+    && usermod -aG docker ${user}
 
 # Jenkins home directory is a volume, so configuration and build history
 # can be persisted and survive image upgrades