# Gitmirror

gitmirror is alternative name of Knotmirror v2. It is designed to be run under the AppView as git syncing service.
It currently speaks XRPC, but because it's internal sync service like tap or hydrant, this API interface can change later.

## Database

`gitmirror-ingest` mirrors `org.tangled.git.refs` records into postgres. `gitmirror-db` owns the
schema; `gitmirror-sync` owns the `state` / `error_msg` / `retry_*` columns it leaves alone.

The two run inside `gitmirror serve`, next to the XRPC server. Ingest
writes a changed record and puts the row back to `pending`; `gitmirror-sync`'s `BackfillWorker`
scans for rows that are behind, fetches, and writes the outcome back. Nothing claims a row in the
database: dedup is an in-memory set, the way hydrant does it, so a crash leaves work eligible
rather than stuck in a state no reaper clears.

Queries are compile-time checked by `sqlx::query!`, and the build has no database, so
`gitmirror/crates/gitmirror-db/.sqlx/` is committed and `SQLX_OFFLINE=true` is set in the
Containerfile and in `nix/pkgs/gitmirror.nix`. It lives inside the crate rather than at the
workspace root because crate2nix builds each crate in isolation. After changing any query:

    cargo check -p gitmirror-db --all-targets     # with the two env vars below
      SQLX_OFFLINE_DIR=$PWD/gitmirror/crates/gitmirror-db/.sqlx
      DATABASE_URL=postgres://tnglr:tnglr@localhost:5432/gitmirror

Then verify the cache is complete with `DATABASE_URL` unset:

    SQLX_OFFLINE=true cargo check -p gitmirror --all-targets

Embedded hydrant is configured through hydrant's own `HYDRANT_*` environment schema; the
collection filter is not among them, since ingest pins it to `org.tangled.git.refs` itself.