[FLINK-5635] [docker] Use start-foreground in Docker entrypoint

docker-entrypoint.sh should error on invalid args

Improve docker build.sh cleanup

Dockerfile improvements per review

Remove unnecessary Dockerfile build steps

Now that docker-entrypoint.sh uses 'start-foreground', munging
flink-daemon.sh and overwriting the log4j config are not longer
necessary.

Improve Dockerfile and docker-entrypoint.sh

Clean up Dockerfile and improve docker-entrypoint.sh to support '--help'
and pass through non-(jobmanager|taskmanager) commands.

This closes apache#3205.
This closes apache#3494.

flink-contrib/docker-flink/Dockerfile

@@ -26,30 +26,20 @@ ENV FLINK_INSTALL_PATH=/opt
 ENV FLINK_HOME $FLINK_INSTALL_PATH/flink
 ENV PATH $PATH:$FLINK_HOME/bin
 
-# These can be mapped from the host to the container using
-# $ docker run -t flink -p 8081:8081 -p 6123:6123 jobmanager
-EXPOSE 8081
-EXPOSE 6123
-
-# flink-dist can point to a directory, a tarball on the local system, or a url to a tarball
+# flink-dist can point to a directory or a tarball on the local system
 ARG flink_dist=NOT_SET
 
 # Install build dependencies and flink
 ADD $flink_dist $FLINK_INSTALL_PATH
 RUN set -x && \
-  mkdir -p $FLINK_INSTALL_PATH && \
   ln -s $FLINK_INSTALL_PATH/flink-* $FLINK_HOME && \
   addgroup -S flink && adduser -D -S -H -G flink -h $FLINK_HOME flink && \
   chown -R flink:flink $FLINK_INSTALL_PATH/flink-* && \
-  chown -h flink:flink $FLINK_HOME && \
-  sed -i -e "s/echo \$mypid >> \$pid/echo \$mypid >> \$pid \&\& wait/g" $FLINK_HOME/bin/flink-daemon.sh
-
-# Configure container
-USER flink
-ADD docker-entrypoint.sh $FLINK_HOME/bin/
+  chown -h flink:flink $FLINK_HOME
 
-# Overwrite default logging settings.  This will additionally log to stdout so we can use 'docker logs'
-ADD log4j.properties $FLINK_HOME/conf/
+COPY docker-entrypoint.sh /
 
-ENTRYPOINT ["docker-entrypoint.sh"]
-CMD ["sh", "-c"]
+USER flink
+EXPOSE 8081 6123
+ENTRYPOINT ["/docker-entrypoint.sh"]
+CMD ["--help"]

flink-contrib/docker-flink/build.sh

@@ -68,7 +68,15 @@ done
 
 IMAGE_NAME=${IMAGE_NAME:-flink}
 
+# TMPDIR must be contained within the working directory so it is part of the
+# Docker context. (i.e. it can't be mktemp'd in /tmp)
 TMPDIR=_TMP_
+
+cleanup() {
+    rm -rf "${TMPDIR}"
+}
+trap cleanup EXIT
+
 mkdir -p "${TMPDIR}"
 
 if [ -n "${FROM_RELEASE}" ]; then
@@ -86,14 +94,15 @@ if [ -n "${FROM_RELEASE}" ]; then
 
 elif [ -n "${FROM_LOCAL}" ]; then
 
-    DIST_DIR="../../flink-dist/target/flink-*-bin"
-    FLINK_DIST="${TMPDIR}/flink.tgz"
-    echo "Using flink dist: ${DIST_DIR}"
-    tar -C ${DIST_DIR} -cvzf "${FLINK_DIST}" .
+  DIST_DIR="../../flink-dist/target/flink-*-bin"
+  FLINK_DIST="${TMPDIR}/flink.tgz"
+  echo "Using flink dist: ${DIST_DIR}"
+  tar -C ${DIST_DIR} -cvzf "${FLINK_DIST}" .
+
 else
+
   usage
+
 fi
 
 docker build --build-arg flink_dist="${FLINK_DIST}" -t "${IMAGE_NAME}" .
-
-rm -rf "${TMPDIR}"

flink-contrib/docker-flink/docker-entrypoint.sh

@@ -19,29 +19,26 @@
 ################################################################################
 
 ### If unspecified, the hostname of the container is taken as the JobManager address
-JOB_MANAGER_RPC_ADDRESS=${JOB_MANAGER_RPC_ADDRESS:-`hostname -f`}
+JOB_MANAGER_RPC_ADDRESS=${JOB_MANAGER_RPC_ADDRESS:-$(hostname -f)}
 ###
 
-if [ "$1" == "jobmanager" ]; then
+if [ "$1" == "--help" -o "$1" == "-h" ]; then
+    echo "Usage: $(basename $0) (jobmanager|taskmanager)"
+    exit 0
+elif [ "$1" == "jobmanager" ]; then
     echo "Starting Job Manager"
     sed -i -e "s/jobmanager.rpc.address: localhost/jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}/g" $FLINK_HOME/conf/flink-conf.yaml
 
     echo "config file: " && grep '^[^\n#]' $FLINK_HOME/conf/flink-conf.yaml
-    $FLINK_HOME/bin/jobmanager.sh start cluster
-
-  # prevent script to exit
-  tail -f /dev/null
+    exec $FLINK_HOME/bin/jobmanager.sh start-foreground cluster
 elif [ "$1" == "taskmanager" ]; then
 
     sed -i -e "s/jobmanager.rpc.address: localhost/jobmanager.rpc.address: ${JOB_MANAGER_RPC_ADDRESS}/g" $FLINK_HOME/conf/flink-conf.yaml
-    sed -i -e "s/taskmanager.numberOfTaskSlots: 1/taskmanager.numberOfTaskSlots: `grep -c ^processor /proc/cpuinfo`/g" $FLINK_HOME/conf/flink-conf.yaml
+    sed -i -e "s/taskmanager.numberOfTaskSlots: 1/taskmanager.numberOfTaskSlots: $(grep -c ^processor /proc/cpuinfo)/g" $FLINK_HOME/conf/flink-conf.yaml
 
     echo "Starting Task Manager"
     echo "config file: " && grep '^[^\n#]' $FLINK_HOME/conf/flink-conf.yaml
-    $FLINK_HOME/bin/taskmanager.sh start
-
-  # prevent script to exit
-  tail -f /dev/null
-else
-    $@
+    exec $FLINK_HOME/bin/taskmanager.sh start-foreground
 fi
+
+exec "$@"