Provide overridable default memory setting

Dockerfile

@@ -13,6 +13,7 @@ RUN apt-get update ;\
     curl -o /tmp/elasticsearch.deb "https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.3.1.deb" ;\
     dpkg -i /tmp/elasticsearch.deb ;\
     rm /tmp/elasticsearch.deb ;\
+    sed -i -E 's/(\-Xm.[0-9]g)/#\1/' /etc/elasticsearch/jvm.options ;\
     rm -rf /var/lib/apt/lists/*
 
 ADD elasticsearch.conf /etc/supervisor/conf.d/elasticsearch.conf

README.md

@@ -15,3 +15,4 @@ Note: you'll need to increase vm.max_map_count; Elasticsearch will demand it. Ei
 
 * Override default config file: `-v /data/myconfig.yml:/etc/elasticsearch/elasticsearch.yml`
 * Data is stored in `/var/lib/elasticsearch`
+* Set memory limit like so: `-e "ES_JAVA_OPTS=-Xms8G -Xmx8G"

start

@@ -1,5 +1,7 @@
 #!/bin/sh
 
+export ES_JAVA_OPTS="${ES_JAVA_OPTS:--Xms1G -Xmx1G}"
+
 exec /usr/share/elasticsearch/bin/elasticsearch \
     -p /var/run/elasticsearch/elasticsearch.pid \
     -E default.path.home=/usr/share/elasticsearch \