feat(elasticsearch): Add optional healthcheck script

Author: lorenjohnson

build/Elasticsearch/Dockerfile

@@ -12,7 +12,7 @@ RUN \
     org.wikimedia.search:extra:${ELASTICSEARCH_PLUGIN_WIKIMEDIA_EXTRA} && \
   ./bin/elasticsearch-plugin install \
     org.wikimedia.search.highlighter:experimental-highlighter-elasticsearch-plugin:${ELASTICSEARCH_PLUGIN_WIKIMEDIA_HIGHLIGHTER}
+COPY healthcheck.sh /healthcheck.sh
 COPY default.jvm.options /default.jvm.options
 RUN cat /default.jvm.options >> /usr/share/elasticsearch/config/jvm.options && \
     rm /default.jvm.options
-

build/Elasticsearch/README.md

@@ -46,24 +46,22 @@ services:
       DB_USER: "mariadb-user"
       DB_PASS: "change-this-password"
       ELASTICSEARCH_HOST: elasticsearch
-    healthcheck:
-      test: curl --silent --fail localhost/wiki/Main_Page
-      interval: 10s
-      start_period: 5m
     depends_on:
       mysql:
         condition: service_healthy
     restart: unless-stopped
+    healthcheck: /healthcheck.sh
 
   wikibase-jobrunner:
     image: wikibase/wikibase
     volumes_from:
       - wikibase
-    command: /jobrunner-entrypoint.sh
     depends_on:
       wikibase:
         condition: service_healthy
     restart: always
+    environment:
+      IS_JOBRUNNER: true
 
   mysql:
     image: mariadb:10.11
@@ -89,10 +87,7 @@ services:
     environment:
       discovery.type: single-node
       ES_JAVA_OPTS: -Xms512m -Xmx512m -Dlog4j2.formatMsgNoLookups=true
-    healthcheck:
-      test: curl --silent --fail localhost:9200
-      interval: 10s
-      start_period: 2m
+    healthcheck: /healthcheck.sh
 
 volumes:
   wikibase-image-data:

build/Elasticsearch/healthcheck.sh

@@ -0,0 +1,17 @@
+#!/bin/bash
+
+# Ref. https://github.com/docker-library/healthcheck/blob/master/elasticsearch/docker-healthcheck
+
+set -eo pipefail
+
+host="$(hostname --ip-address || echo '127.0.0.1')"
+
+if health="$(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" = 'green' ]; then
+		exit 0
+	fi
+	echo >&2 "unexpected health status: $health"
+fi
+
+exit 1