Containerfile: add cargo-chef for dependency-layer caching in podman build

gal-bot commented

2026-08-19 06:38:50 +00:00

Owner

The two-stage Containerfile copies Cargo.toml + src/ together then runs cargo build --release — every source change invalidates the build layer → full dependency recompile every deploy.

Fix: adopt the cargo-chef planner/cache/cooker pattern:

planner stage: cargo chef prepare --recipe-path recipe.json from Cargo.toml/Cargo.lock
cache stage: cargo chef cook --release --recipe-path recipe.json — dep compilation, cached as a layer
builder stage: copy recipe + sources, cargo build --release — only recompiles app code unless deps change

Effect: dep changes only recompile when Cargo.toml/Cargo.lock actually change; day-to-day source-only pushes reuse the cached dep layer (seconds vs minutes).

This is app-level (this Containerfile) but the archetype comes from the ditc scaffold — the template should adopt cargo-chef too so new apps inherit it (cross-reference: dit-client template ticket).

The two-stage Containerfile copies `Cargo.toml` + `src/` together then runs `cargo build --release` — every source change invalidates the build layer → full dependency recompile every deploy. Fix: adopt the [cargo-chef](https://github.com/lukemartinwalker/cargo-chef) planner/cache/cooker pattern: 1. `planner` stage: `cargo chef prepare --recipe-path recipe.json` from Cargo.toml/Cargo.lock 2. `cache` stage: `cargo chef cook --release --recipe-path recipe.json` — dep compilation, cached as a layer 3. `builder` stage: copy recipe + sources, `cargo build --release` — only recompiles app code unless deps change Effect: dep changes only recompile when Cargo.toml/Cargo.lock actually change; day-to-day source-only pushes reuse the cached dep layer (seconds vs minutes). This is app-level (this Containerfile) but the archetype comes from the ditc scaffold — the template should adopt cargo-chef too so new apps inherit it (cross-reference: dit-client template ticket).

jsutter referenced this issue

2026-08-21 21:48:07 +00:00

CI: speed up nix-shell cargo test/clippy (persist target cache + pin flake + sccache opt-in) #2

jsutter commented

2026-08-21 21:48:08 +00:00

Owner

Superseded by #11 (migrate to dynamic-nix). dynamic-nix has no Containerfile, so cargo-chef (#3) and sccache (#2) become throwaway work — nix build derivation caching replaces both. Do not start these until #11 is decided. If #11 does not proceed, these remain valid.

jsutter referenced this issue

2026-08-21 21:48:19 +00:00

CI: speed up nix-shell cargo test/clippy (persist target cache + pin flake + sccache opt-in) #2

jsutter commented

2026-08-21 21:48:19 +00:00

Owner

Superseded by #11 (migrate to dynamic-nix). dynamic-nix has no Containerfile, so cargo-chef (#3) and sccache (#2) become throwaway work — nix build derivation caching replaces both. Do not start these until #11 is decided. If #11 does not proceed, these remain valid.

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Containerfile: add cargo-chef for dependency-layer caching in podman build #3