feature: docker development environment (#544)

Add docker support

It's self-contained so should not interfere with anything else and can easily be thrown out if nobody wants it anymore.

.docker/entrypoint-sync.sh

@@ -0,0 +1,32 @@
+#!/bin/bash
+
+# set +x
+
+pushd /nyaa
+
+echo 'Waiting for MySQL to start up'
+while ! echo HELO | nc mariadb 3306 &>/dev/null; do
+	sleep 1
+done
+echo 'DONE'
+
+echo 'Waiting for ES to start up'
+while ! echo HELO | nc elasticsearch 9200 &>/dev/null; do
+	sleep 1
+done
+echo 'DONE'
+
+echo 'Waiting for ES to be ready'
+while ! curl -s -XGET 'elasticsearch:9200/_cluster/health?pretty=true&wait_for_status=green' &>/dev/null; do
+	sleep 1
+done
+echo 'DONE'
+
+echo 'Waiting for sync data file to exist'
+while ! [ -f /elasticsearch-sync/pos.json ]; do
+	sleep 1
+done
+echo 'DONE'
+
+echo 'Starting the sync process'
+/usr/bin/python3 /nyaa/sync_es.py /nyaa/.docker/es_sync_config.json