doc: nvfetcher

doc/SUMMARY.md

@@ -31,5 +31,6 @@
 - [Integrations](./integrations/index.md)
   - [Cachix](./integrations/cachix.md)
   - [Deploy RS](./integrations/deploy.md)
+  - [NvFetcher](./integrations/nvfetcher.md)
   - [Hercules CI](./integrations/hercules.md)
 - [Contributing](./CONTRIBUTING.md)

doc/integrations/nvfetcher.md

@@ -0,0 +1,43 @@
+# nvfetcher
+[NvFetcher][nvf] is a workflow companion for updating nix sources.
+
+You can specify an origin source and an update configuration, and
+nvfetcher can for example track updates to a specific branch and
+automatically update your nix sources configuration on each run
+to the tip of that branch.
+
+All package source declaration is done in [sources.toml][sources.toml].
+
+From within the devshell of this repo, run `nvfetcher`, a wrapped
+version of `nvfetcher` that knows where to find and place its files
+and commit the results.
+
+## Usage
+
+Statically fetching (not tracking) a particular tag from a github repo:
+```toml
+[manix]
+src.manual = "v0.6.3"
+fetch.github = "mlvzk/manix"
+```
+
+Tracking the latest github _release_ from a github repo:
+```toml
+[manix]
+src.github = "mlvzk/manix" # responsible for tracking
+fetch.github = "mlvzk/manix" # responsible for fetching
+```
+
+Tracking the latest commit of a git repository and fetch from a git repo:
+```toml
+[manix]
+src.git = "https://github.com/mlvzk/manix.git" # responsible for tracking
+fetch.git = "https://github.com/mlvzk/manix.git" # responsible for fetching
+```
+
+> ##### _Note:_
+> Please refer to the [NvFetcher Readme][nvf-readme] for more options.
+
+[nvf: https://github.com/berberman/nvfetcher
+[nvf-readme]: https://github.com/berberman/nvfetcher#readme
+[sources.toml]: https://github.com/divnix/devos/tree/core/pkgs/sources.toml