feat: execute service as distributed erlang (#96)

To create a cluster with distributed nodes, the following changes were made:

* Use [`dns_cluster`][0] to execute distributed nodes
* Add _script_ to execute distributed nodes locally

Also, improve local execution by:

* Use [`mix release`][1] to make easier [deploy `phoenix`][2]
* Use [`compose watch`][3] to synchronize code from the host with the service

Some minor improvements:

* Ignore files and folders in git and docker
* Remove boilerplate comments

[0]: https://github.com/phoenixframework/dns_cluster
[1]: https://hexdocs.pm/mix/Mix.Tasks.Release.html
[2]: https://hexdocs.pm/phoenix/releases.html
[3]: https://docs.docker.com/compose/how-tos/file-watch/

Co-authored-by: Joao P Dubas <joao.dubas@gmail.com>
Reviewed-on: #96
Co-authored-by: Joao P Dubas <joao.dubas+gitea@gmail.com>
Co-committed-by: Joao P Dubas <joao.dubas+gitea@gmail.com>

Makefile

@@ -32,21 +32,17 @@ test:  ## run tests
 compose_up:  ## start containers for this service
 	@$(COMPOSE) up -d
 
-.PHONY: compose_deps_upgrade
-compose_deps_upgrade:  ## install/upgrade deps
-	@$(COMPOSE) run --entrypoint mix app do deps.get, deps.compile, compile
-
-.PHONY: compose_test
-compose_test:  ## run tests in containers
-	@$(COMPOSE) run -e MIX_ENV=test --entrypoint make app test
+.PHONY: compose_watch
+compose_watch:  ## start containers for this service watching for updates in filesystem
+	@$(COMPOSE) up -w
 
 .PHONY: compose_database_create
 compose_database_create:
-	@$(COMPOSE) --profile setup run db_setup
+	@$(COMPOSE) run --rm --entrypoint mix app ecto.create
 
 .PHONY: compose_database_migrate
 compose_database_migrate:  ## apply migrations to our database
-	@$(COMPOSE) --profile migrate run db_migrate
+	@$(COMPOSE) run --rm --entrypoint mix app ecto.migrate
 
 .PHONY: compose_database_setup
 compose_database_setup: compose_database_create compose_database_migrate  ## create and apply migrations
@@ -55,6 +51,10 @@ compose_database_setup: compose_database_create compose_database_migrate  ## cre
 compose_ps:  ## status of containers
 	@$(COMPOSE) ps
 
+.PHONY: compose_remote
+compose_remote:  ## connect to remote node
+	@$(COMPOSE) exec app ./priv/docker/service/docker-remote.sh
+
 .PHONY: help
 help:
 	@grep -E '^[a-zA-Z_-]+:.*?## .*$$' $(MAKEFILE_LIST) | sort | awk 'BEGIN {FS = ":.*?## "}; {printf "\033[36m%-30s\033[0m %s\n", $$1, $$2}'