use docker healthcheck

build/elasticsearch/Dockerfile

@@ -34,6 +34,16 @@ COPY elasticsearch.yml config/
 COPY log4j2.properties config/
 COPY bin/es-docker bin/es-docker
 
+# Healthcheck. Copied from
+# https://github.com/docker-library/healthcheck/blob/master/elasticsearch/Dockerfile
+# Set to yellow for the case of running 1 node, like note in 
+# tests/test_basic_index_crud.py # test_cluster_health_after_crud
+# Reference: https://docs.docker.com/engine/reference/builder/#/healthcheck
+#
+# TODO How to detect that 2 nodes are running and wait for "green"?
+COPY docker-healthcheck /usr/local/bin/
+HEALTHCHECK CMD ["/bin/bash","docker-healthcheck","yellow"]
+
 USER root
 RUN chown elasticsearch:elasticsearch config/elasticsearch.yml config/log4j2.properties bin/es-docker && \
     chmod 0750 bin/es-docker

build/elasticsearch/docker-healthcheck

@@ -0,0 +1,31 @@
+#!/bin/bash
+# Copied from https://github.com/docker-library/healthcheck/tree/master/elasticsearch/docker-healthcheck
+# Usage: docker-healthcheck  # by default, waits for "green"
+#        docker-healthcheck yellow # to wait for "yellow" instead
+
+target='green'
+if [ ! -z "$1" ]; then
+  target="$1"
+fi
+
+set -eo pipefail
+
+# Use -i instead of --ip-address in case hostname was just a symlink to busybox
+# The busybox version of hostname supports -i and not --ip-address
+# Both busybox/hostname and the GNU hostname support -i
+# References:
+# https://busybox.net/downloads/BusyBox.html#hostname
+# https://linux.die.net/man/1/hostname
+# http://manpages.ubuntu.com/manpages/precise/man1/hostname.1.html
+host="$(hostname -i || echo '127.0.0.1')"
+
+# TODO with xpack, the below curl will fail with "unauthorized" error if xpack is enabled
+if health="$(curl -fsSL "http://$host:9200/_cat/health?h=status")"; then
+  health="$(echo "$health" | sed -r 's/^[[:space:]]+|[[:space:]]+$//g')" # trim whitespace (otherwise we'll have "green ")
+  if [ "$health" = "$target" ]; then
+    exit 0
+  fi
+  echo >&2 "unexpected health status: $health"
+fi
+
+exit 1

docker-compose.yml

@@ -1,5 +1,5 @@
 ---
-version: '2'
+version: '2.1'
 services:
   # Can't use service elasticsearch=<num> for now due to named volumes
   elasticsearch1:
@@ -66,6 +66,13 @@ services:
       - elasticsearch1:elasticsearch
     volumes:
       - $PWD/tests:/home/testuser/tests:ro
+    # Despite the python tester having a built-in healthcheck at tests/es_acceptance.py#wait_for_cluster_health
+    # Using the dockerfile healthcheck extends this to other services without having to re-code a wait for health status in each
+    # Note that this requires docker-compose.yml version 2.1, docker-compose>=1.11, docker>=1.13
+    depends_on:
+      elasticsearch1:
+        condition: service_healthy
+
 volumes:
   esdata1:
     driver: local