Enhancement: Add Docker Hub image (#965)

* Enhancement: Add Docker Hub image

* Push to ghcr.io

* Add all `org.opencontainers.image.xxx` labels using `--label` instead of `LABEL`

* Change `php-fpm` to listen on `:9000` to expose prometheus metrics via `php-fpm_exporter`

* Include `yarn.lock` to speed up builds

* Reorder

* Use correct sha for pr

* Add logging before overriding values in config

* Add `DEBUG=true` env var for verbose `entrypoint.sh` logs

* Print php exception when snappymail fails to generate data directory and config file on the very first time

* Log snappymail version

* Fix COPY statement

* Add .dockerignore

* Add `USER` and `ENTRYPOINT`

* Update `.dockerignore`

* Add docker image test

* Push only if image test succeeds

* Log when startup is successful

* Use plain `docker build` in `build_and_test.sh`

* Fix test output

examples/docker-compose.postgres.yml

@@ -0,0 +1,56 @@
+version: '2'
+services:
+  snappymail:
+    image: leojonathanoh/snappymail:pr-1
+    ports:
+      - 8888:8888
+    environment:
+      - DEBUG=true
+    volumes:
+      - snappymail:/var/lib/snappymail
+    networks:
+      - default
+      - db-network
+      - redis-network
+    restart: unless-stopped
+
+  # This provides prometheus metrics for snappymail's php-fpm
+  php-fpm-exporter:
+    image: hipages/php-fpm_exporter:2.2.0
+    ports:
+      - 9253:9253
+    environment:
+      - PHP_FPM_SCRAPE_URI=tcp://snappymail:9000/status
+    networks:
+      - default
+
+  db:
+    image: postgres:15-alpine
+    environment:
+      - POSTGRES_USER=snappymail
+      - POSTGRES_PASSWORD=snappymail
+      - POSTGRES_DB=snappymail
+    volumes:
+      - postgres:/var/lib/postgresql/data
+    networks:
+      - db-network
+    restart: unless-stopped
+
+  redis:
+    image: redis:7-alpine
+    networks:
+      - redis-network
+    restart: unless-stopped
+
+networks:
+  default:
+  db-network:
+    internal: true
+  redis-network:
+    internal: true
+
+volumes:
+  postgres:
+    driver: local
+  snappymail:
+    driver: local