Honor SIGINT in Docker container

Use intermediate shell script to forward environment variables then
exec java.

Dockerfile

@@ -2,7 +2,8 @@ FROM anapsix/alpine-java:jre7
 MAINTAINER Andrew Gaul <andrew@gaul.org>
 
 WORKDIR /opt/s3proxy
-COPY target/s3proxy /opt/s3proxy/s3proxy
+COPY target/s3proxy /opt/s3proxy/
+COPY src/main/resources/run-docker-container.sh /opt/s3proxy/
 
 ENV \
     LOG_LEVEL="info" \
@@ -17,15 +18,4 @@ ENV \
 EXPOSE 80
 VOLUME /data
 
-ENTRYPOINT java \
-    -DLOG_LEVEL=${LOG_LEVEL} \
-    -Ds3proxy.endpoint=http://0.0.0.0:80 \
-    -Ds3proxy.authorization=${S3PROXY_AUTHORIZATION} \
-    -Ds3proxy.identity=${S3PROXY_IDENTITY} \
-    -Ds3proxy.credential=${S3PROXY_CREDENTIAL} \
-    -Djclouds.provider=${JCLOUDS_PROVIDER} \
-    -Djclouds.identity=${JCLOUDS_IDENTITY} \
-    -Djclouds.credential=${JCLOUDS_CREDENTIAL} \
-    -Djclouds.filesystem.basedir=/data \
-    -jar /opt/s3proxy/s3proxy \
-    --properties /dev/null
+ENTRYPOINT ["/opt/s3proxy/run-docker-container.sh"]

src/main/resources/run-docker-container.sh

@@ -0,0 +1,14 @@
+#!/bin/sh
+
+exec java \
+    -DLOG_LEVEL=${LOG_LEVEL} \
+    -Ds3proxy.endpoint=http://0.0.0.0:80 \
+    -Ds3proxy.authorization=${S3PROXY_AUTHORIZATION} \
+    -Ds3proxy.identity=${S3PROXY_IDENTITY} \
+    -Ds3proxy.credential=${S3PROXY_CREDENTIAL} \
+    -Djclouds.provider=${JCLOUDS_PROVIDER} \
+    -Djclouds.identity=${JCLOUDS_IDENTITY} \
+    -Djclouds.credential=${JCLOUDS_CREDENTIAL} \
+    -Djclouds.filesystem.basedir=/data \
+    -jar /opt/s3proxy/s3proxy \
+    --properties /dev/null