Mastering Rust: Production Configuration & Build Caching

[build]
# Enable sccache globally or per project (requires sccache installed in PATH)
# rustc-wrapper = "sccache"

[profile.dev]
opt-level = 1           # Fast build in dev with basic dependency optimization

[profile.release]
opt-level = 3
lto = "fat"             # Link-Time Optimization for maximum performance
codegen-units = 1      # Maximum optimization for binary size and speed
panic = "abort"        # Removes stack unwinding infrastructure (reduces size)
strip = true           # Automatically strips debug symbols

[target.x86_64-unknown-linux-gnu]
# Fast linker for builds (requires mold or lld to be installed)
linker = "clang"
rustflags = ["-C", "link-arg=-fuse-ld=mold"]

[lints.rust]
unsafe_code = "forbid"
unreachable_pub = "warn"

[lints.clippy]
pedantic = { level = "warn", priority = -1 }
unwrap_used = "warn"

# 1. Install sccache locally via cargo binstall or cargo install
cargo install sccache --locked

# 2. Enable sccache via environment variables (e.g. in .bashrc / .zshrc)
export RUSTC_WRAPPER=sccache

# Disable incremental compilation (required for sccache to work properly)
export CARGO_INCREMENTAL=0

# Configure local cache size (default is 10GB)
export SCCACHE_DIR=$HOME/.cache/sccache
export SCCACHE_CACHE_SIZE="20G"

# 3. Check cache usage statistics
sccache --show-stats

# --- STAGE 1: Chef Planner (Dependency Caching) ---
FROM lukemathwalker/cargo-chef:latest-rust-1.80-bullseye AS chef
WORKDIR /app

FROM chef AS planner
COPY . .
RUN cargo chef prepare --recipe-path recipe.json

# --- STAGE 2: Builder (Building dependencies and application code) ---
FROM chef AS builder
ARG APP_NAME=DEFINE_ME

RUN apt-get update &&     apt-get install -y musl-tools upx &&     rustup target add x86_64-unknown-linux-musl

# Build dependencies only (cached by Docker layers)
COPY --from=planner /app/recipe.json recipe.json
RUN cargo chef cook --release --target x86_64-unknown-linux-musl --recipe-path recipe.json

# Build application source code
COPY . .
RUN cargo build --release --target x86_64-unknown-linux-musl --bin ${APP_NAME} &&     strip target/x86_64-unknown-linux-musl/release/${APP_NAME} &&     upx --best --lzma target/x86_64-unknown-linux-musl/release/${APP_NAME}

# --- STAGE 3: Runtime (Minimal Distroless) ---
FROM gcr.io/distroless/static-debian12:nonroot
ARG APP_NAME=DEFINE_ME

COPY --from=builder /app/target/x86_64-unknown-linux-musl/release/${APP_NAME} /usr/local/bin/app

USER nonroot:nonroot
ENTRYPOINT ["/usr/local/bin/app"]

[changelog]
header = """
# Changelog\n
All notable changes to this project will be documented in this file.\n
"""
body = """
{% if version %}\
    {% if previous.version %}\
        ## [{{ version | trim_start_matches(pat="v") }}](<REPO>/compare/{{ previous.version }}..{{ version }}) - {{ timestamp | date(format="%Y-%m-%d") }}
    {% else %}\
        ## {{ version | trim_start_matches(pat="v") }} - {{ timestamp | date(format="%Y-%m-%d") }}
    {% endif %}\
{% else %}\
    ## unreleased
{% endif %}\

{% for group, commits in commits | group_by(attribute="group") %}
    ### {{ group | upper_first }}
    {% for commit in commits %}
        - {{ commit.message | upper_first }} - ([{{ commit.id | truncate(length=7, end="") }}](<REPO>/commit/{{ commit.id }}))\
    {% endfor %}
{% endfor %}\n
"""
footer = """
<!-- generated by git-cliff -->
"""
trim = true

postprocessors = [
  { pattern = '<REPO>', replace = "https://github.com/t1ltxz-gxd/tiltflake" },
]

[git]
conventional_commits = true
filter_unconventional = true
split_commits = false

commit_preprocessors = [
  { pattern = '\((\w+\s)?#([0-9]+)\)', replace = "([#${2}](<REPO>/issues/${2}))" },
  { pattern = ' +$', replace = "" },
  { pattern = ' +', replace = " " },
  { pattern = ' *(:\w+:|[\p{Emoji_Presentation}\p{Extended_Pictographic}](?:\u{FE0F})?\u{200D}?) *', replace = "" },
]

commit_parsers = [
  { message = "^feat", group = "<!-- 0 -->🚀 Features" },
  { message = "^fix", group = "<!-- 1 -->🐛 Bug Fixes" },
  { message = "^doc", group = "<!-- 3 -->📚 Documentation" },
  { message = "^perf", group = "<!-- 4 -->⚡ Performance" },
  { message = "^refactor", group = "<!-- 2 -->🚜 Refactor" },
  { message = "^style", group = "<!-- 5 -->🎨 Styling" },
  { message = "^test", group = "<!-- 6 -->🧪 Testing" },
  { message = "^chore\(release\): prepare for", skip = true },
  { message = "^chore\(deps.*\)", skip = true },
  { message = "^chore\(pr\)", skip = true },
  { message = "^chore\(pull\)", skip = true },
  { message = "^chore|^ci", group = "<!-- 7 -->⚙️ Miscellaneous Tasks" },
  { body = ".*security", group = "<!-- 8 -->🛡️ Security" },
  { message = "^revert", group = "<!-- 9 -->◀️ Revert" },
]
filter_commits = false
topo_order = false
sort_commits = "oldest"

pre-release-commit-message = ":rocket: chore(release): version {{version}}"
shared-version = true
sign-commit = false
tag-message = "{{version}}"
tag-prefix = ""
publish = false
push = true
tag = true
pre-release-hook = ["git", "cliff", "-o", "CHANGELOG.md", "--tag", "{{version}}"]

# rust-toolchain.toml
[toolchain]
channel = "1.80.0"
components = ["rustfmt", "clippy"]

# rustfmt.toml
edition = "2021"
hard_tabs = true
max_width = 100
use_small_heuristics = "Max"
reorder_imports = true

name: CI

on:
  push:
    branches: [ main ]
  pull_request:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Install Rust Toolchain
        uses: dtolnay/rust-toolchain@stable
        with:
          components: clippy, rustfmt

      - name: Run sccache-action
        uses: mozilla-actions/sccache-action@v2

      - name: Set Environment Variables for Sccache
        run: |
          echo "RUSTC_WRAPPER=sccache" >> $GITHUB_ENV
          echo "SCCACHE_GHA_ENABLED=true" >> $GITHUB_ENV

      - name: Check Formatting
        run: cargo fmt --all -- --check

      - name: Run Clippy Lints
        run: cargo clippy --all-targets -- -D warnings

      - name: Run Tests
        run: cargo test --all