Docker: fix cache hugepage requirement

Allow users to use the Crail shell without providing
hugepages via a volume mount to Docker.

Signed-off-by: Jonas Pfefferle <pepperjo@apache.org>

docker/Dockerfile

@@ -17,7 +17,7 @@ FROM ubuntu:18.04
 MAINTAINER Apache Crail <dev@crail.apache.org>
 
 # TODO: automate update version on new release
-ARG GIT_COMMIT="v1.0"
+ARG GIT_COMMIT="master"
 ENV LOG_COMMIT=$GIT_COMMIT
 
 RUN echo "Crail-$LOG_COMMIT install openjdk8, git and envsubst" && \
@@ -41,19 +41,18 @@ RUN echo "Crail-$LOG_COMMIT clone & build Crail repo" && \
 ENV CRAIL_HOME /incubator-crail/assembly/target/crail-1.0-bin
 ENV PATH=${PATH}:${CRAIL_HOME}/bin
 
-RUN echo "Crail-$LOG_COMMIT update crail script to update core-site.xml" && \
-    sed -i '$ienvsubst < $CRAIL_HOME/conf/core-site.xml > $CRAIL_HOME/conf/core-site.xml' $CRAIL_HOME/bin/crail
 
 ENV NAMENODE_HOST=localhost
 ENV NAMENODE_PORT=9060
 ENV INTERFACE=eth0
 ENV DATAPATH=/dev/hugepages/data
 ENV STORAGELIMIT=1073741824
 ENV CACHEPATH=/dev/hugepages/cache
-ENV CACHELIMIT=1073741824
+ENV CACHELIMIT=0
 
+COPY ./start-crail-docker.sh $CRAIL_HOME/bin
 COPY ./crail-env.sh $CRAIL_HOME/conf
 COPY ./core-site.xml $CRAIL_HOME/conf
 COPY ./crail-site.conf $CRAIL_HOME/conf
 
-ENTRYPOINT ["crail"]
+ENTRYPOINT ["start-crail-docker.sh"]

docker/start-crail-docker.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# substitude env variables in core-site.xml
+envsubst < $CRAIL_HOME/conf/core-site.xml > $CRAIL_HOME/conf/core-site.xml
+
+crail $@