Kubernetes initiates "graceful shutdown" by sending SIGTERM to pid 1.
The way the existing startup scripts worked, this signal arrived at
the shell wrapper, not elasticsearch, and the shell wrapper exited,
killing the container immediately.
Before this change:
1 ? Ss 0:00 /bin/sh -c /run.sh
6 ? S 0:00 /bin/bash /run.sh
13 ? S 0:00 \_ /bin/su -c /elasticsearch/bin/elasticsearch elasticsearch
14 ? Ss 0:00 \_ sh -c /elasticsearch/bin/elasticsearch
15 ? Sl 19:18 \_ /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java ... org.elasticsearch.bootstrap.Elasticsearch start
After this change:
1 ? Ssl 0:29 /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java ... org.elasticsearch.bootstrap.Elasticsearch start
