nixify-haskell: Part 4

en/nixify-haskell.md

@@ -6,6 +6,7 @@ This is a #[[tutorial|tutorial]] series on nixifying #[[haskell]] projects. In p
 1. [x] [[nixify-haskell-nixpkgs]]#
 2. [ ] [[nixify-haskell-parts]]#
 3. [ ] [[nixify-haskell-flake]]#
+4. [ ] [[nixify-services-flake]]#
 
 [^other]: There are also other approaches (like [haskell.nix](https://github.com/input-output-hk/haskell.nix), [stacklock2nix](https://github.com/cdepillabout/stacklock2nix)).
 

en/nixify-services-flake.md

@@ -0,0 +1,16 @@
+---
+short-title: 4. Using services-flake
+---
+
+# Integrating external services using services-flake
+
+>[!warning] TODO: Write this! 
+> For now, see the code: https://github.com/juspay/todo-app/pull/22
+
+Things to highlight:
+
+- `services-flake` provides pre-defined configurations for many services, reducing a bunch of lines to just `services.<service>.<instance>.enable = true;`
+- Data directory for all services in `services-flake` is local to the project working directory, by default
+- Best practices:
+  - Use Unix sockets for local development and CI to avoid binding to ports (which is global to the interface)
+  - Write integration tests using the reserved `test` process in `process-compose-flake`.