Code for Zero to Production in Rust

My code from working through Zero to Production in Rust.

Initial setup

• Install Rust
• Install Docker
• brew install libpq to install psql
• cargo install sqlx-cli --no-default-features --features rustls,postgres
• cargo install bunyan for pretty printing logs

Development

Run app

• bash scripts/init_db.sh to start database server in Docker container (detached) for testing
• SKIP_DOCKER=true bash scripts/init_db.sh to apply migrations to database running in container
• psql -h localhost -p 5432 -U postgres to connect to database server from command line
• cargo run | bunyan to run app with pretty-printed logs
• cargo watch --exec 'run | bunyan' --ignore *.md to run app on file changes

Run tests

• cargo watch --exec check --exec test --ignore *.md to run tests on file changes
• TEST_LOG=true cargo test to see logs from tests, or TEST_LOG=true cargo test | bunyan with pretty printing

To manually test API endpoints, use for example:

• curl -v http://127.0.0.1:8000/health_check
• curl -v http://127.0.0.1:8000/subscriptions -H "Content-Type: application/x-www-form-urlencoded" -d "email=test@test.com&name=tester"

Known issues

If you see the following error, you can increase the maximum number of open file handles:

thread 'actix-server worker ...' panicked at ... called Result::unwrap() on an Err value: Os { code: 24, kind: Uncategorized, message: "Too many open files" }

• ulimit -Sn to see the current soft limit
• ulimit -Sn <value> to set a new limit for the current Shell session, e.g. ulimit -Sn 1000

Inspect database

• psql -h localhost -p 5432 -U postgres to connect to the database server from command line

Build Docker image

• cargo sqlx prepare --workspace, to work with sqlx offline, together with SQLX_OFFLINE=true
• docker build --tag zero2prod --file Dockerfile .
• docker run -p 8000:8000 zero2prod

Notes

Tools

• cargo clippy for linting
• cargo tarpaulin --ignore-tests for code coverage
• cargo watch for triggering commands automatically on code changes
• cargo audit to check for vulnerabilities
• cargo expand to show result of macro expansions
• cargo +nightly udeps to remove unused dependencies, requires rustup toolchain install nightly
• cargo tree to display dependency tree, useful for debugging incompatible dependencies

Commands

• rustup update to update the Rust toolchain including rustc and cargo
• tmux new-session -t <existing-session> to attach to the same session multiple times and switch windows independently, using tmux grouped sessions (see SO post), e.g. for monitoring output from cargo watch commands in separate windows