complement-synapse-workers: factor out separate entry point script (#12467)

... with a bit more verbosity.

docker/complement/conf-workers/start-complement-synapse-workers.sh

@@ -0,0 +1,50 @@
+#!/bin/bash
+#
+# Default ENTRYPOINT for the docker image used for testing synapse with workers under complement
+
+set -e
+
+function log {
+    d=$(date +"%Y-%m-%d %H:%M:%S,%3N")
+    echo "$d $@"
+}
+
+# Replace the server name in the caddy config
+sed -i "s/{{ server_name }}/${SERVER_NAME}/g" /root/caddy.json
+
+log "starting postgres"
+pg_ctlcluster 13 main start
+
+log "starting caddy"
+/root/caddy start --config /root/caddy.json
+
+# Set the server name of the homeserver
+export SYNAPSE_SERVER_NAME=${SERVER_NAME}
+
+# No need to report stats here
+export SYNAPSE_REPORT_STATS=no
+
+# Set postgres authentication details which will be placed in the homeserver config file
+export POSTGRES_PASSWORD=somesecret
+export POSTGRES_USER=postgres
+export POSTGRES_HOST=localhost
+
+# Specify the workers to test with
+export SYNAPSE_WORKER_TYPES="\
+    event_persister, \
+    event_persister, \
+    background_worker, \
+    frontend_proxy, \
+    event_creator, \
+    user_dir, \
+    media_repository, \
+    federation_inbound, \
+    federation_reader, \
+    federation_sender, \
+    synchrotron, \
+    appservice, \
+    pusher"
+
+# Run the script that writes the necessary config files and starts supervisord, which in turn
+# starts everything else
+exec /configure_workers_and_start.py