docs: README and docs

docs/images-and-compose-files.md

@@ -9,7 +9,7 @@ There's 4 images that you can find in `/build` directory:
 
 > `nginx`, `socketio` and `worker` images — everything we need to be able to run all processes that Frappe framework requires (take a look at [Bench Procfile reference](https://frappeframework.com/docs/v13/user/en/bench/resources/bench-procfile)). We follow [Docker best practices](https://docs.docker.com/develop/develop-images/dockerfile_best-practices/#decouple-applications) and split these processes to different containers.
 
-> ERPNext images don't have their own Dockerfiles. We use [multi-stage builds](https://docs.docker.com/develop/develop-images/multistage-build/) and [Docker Buildx](https://docs.docker.com/engine/reference/commandline/buildx/) to reuse as much things as possible and make are builds more efficient.
+> ERPNext images don't have their own Dockerfiles. We use [multi-stage builds](https://docs.docker.com/develop/develop-images/multistage-build/) and [Docker Buildx](https://docs.docker.com/engine/reference/commandline/buildx/) to reuse as much things as possible and make our builds more efficient.
 
 # Compose files
 
@@ -23,8 +23,8 @@ All services are described in `compose.yaml`
 
 - `configurator`. Updates `common_site_config.json` so Frappe knows how to access db and redis. It is executed on every `docker-compose up` (and exited immediately). Other services start after this container exits successfully.
 - `backend`. [Werkzeug server](https://werkzeug.palletsprojects.com/en/2.0.x/).
-- `db`. [MariaDB](https://mariadb.com), can be overwritten with [Postgres](https://www.postgresql.org) if you also use `overrides/compose.postgres.yaml`.
-- `redis`. [Redis](https://redis.io) server with cache, [Socket.IO](https://socket.io) and queues data.
+- `db`. Optional service that runs [MariaDB](https://mariadb.com) if you also use `overrides/compose.mariadb.yaml` or [Postgres](https://www.postgresql.org) if you also use `overrides/compose.postgres.yaml`.
+- `redis`. Optional service that runs [Redis](https://redis.io) server with cache, [Socket.IO](https://socket.io) and queues data.
 - `frontend`. [nginx](https://www.nginx.com) server that serves JS/CSS assets and routes incoming requests.
 - `proxy`. [Traefik](https://traefik.io/traefik/) proxy. It is here for complicated setups or HTTPS override (with `overrides/compose.https.yaml`).
 - `websocket`. Node server that runs [Socket.IO](https://socket.io).
@@ -35,15 +35,20 @@ All services are described in `compose.yaml`
 
 We have several [overrides](https://docs.docker.com/compose/extends/):
 
+- `overrides/compose.proxy.yaml`. Adds traefik proxy to setup.
+- `overrides/compose.noproxy.yaml`. Publishes `frontend` ports directly without any proxy.
 - `overrides/compose.erpnext.yaml`. Replaces all Frappe images with ERPNext ones. ERPNext images are built on top of Frappe ones, so it is safe to replace them.
 - `overrides/compose.https.yaml`. Automatically sets up Let's Encrypt certificate and redirects all requests to directed to http, to https.
-- `overrides/compose.postgres.yaml`. Replaces `db` service's image from MariaDB to Postgres. Note that ERPNext currently doesn't support Postgres.
+- `overrides/compose.mariadb.yaml`. Adds `db` service and sets its image to MariaDB.
+- `overrides/compose.postgres.yaml`. Adds `db` service and sets its image to Postgres. Note that ERPNext currently doesn't support Postgres.
+- `overrides/compose.redis.yaml`. Adds `redis` service and sets its image to `redis`.
+- `overrides/compose.swarm.yaml`. Workaround override for generating swarm stack.
 
 It is quite simple to run overrides. All we need to do is to specify compose files that should be used by docker-compose. For example, we want ERPNext:
 
 ```bash
 # Point to main compose file (compose.yaml) and add one more.
-docker-compose -f compose.yaml -f overrides/compose.erpnext.yaml
+docker-compose -f compose.yaml -f overrides/compose.erpnext.yaml config
 ```
 
 That's it! Of course, we also have to setup `.env` before all of that, but that's not the point.
@@ -60,6 +65,26 @@ Frappe framework release. You can find all releases [here](https://github.com/fr
 
 Password for MariaDB (or Postgres) database.
 
+### `DB_HOST`
+
+Hostname for MariaDB (or Postgres) database. Set only if external service for database is used.
+
+### `DB_PORT`
+
+Port for MariaDB (3306) or Postgres (5432) database. Set only if external service for database is used.
+
+### `REDIS_CACHE`
+
+Hostname for redis server to store cache. Set only if external service for redis is used.
+
+### `REDIS_QUEUE`
+
+Hostname for redis server to store queue data. Set only if external service for redis is used.
+
+### `REDIS_SOCKETIO`
+
+Hostname for redis server to store socketio data. Set only if external service for redis is used.
+
 ### `ERPNEXT_VERSION`
 
 ERPNext [release](https://github.com/frappe/frappe/releases). This variable is required if you use ERPNext override.