Rust Project

Environment validation for Rust applications

Overview

This example demonstrates envcheck configuration for a Rust project. It validates the Rust toolchain, optional environment variables for logging and database connectivity, and required Cargo files.

Configuration

.envcheck.yaml

version: "1"

tools:
  - name: rustc
    version: ">=1.65.0"
    required: true
  - name: cargo
    required: true

env_vars:
  - name: RUST_LOG
    required: false
  - name: DATABASE_URL
    required: false

files:
  - path: Cargo.toml
    required: true
  - path: src/main.rs
    required: false
  - path: src/lib.rs
    required: false

What This Checks

Tools

• rustc >=1.65.0: Ensures you have a modern Rust compiler with the 2021 edition features
• cargo: Validates Rust’s package manager and build tool is available

Environment Variables

• RUST_LOG (optional): Controls logging verbosity for applications using env_logger or tracing
• DATABASE_URL (optional): Connection string for database access when using SQLx or Diesel

Files

• Cargo.toml: Project manifest - required for all Rust projects
• src/main.rs (optional): Binary entry point - checked for application projects
• src/lib.rs (optional): Library entry point - checked for library crates

Expected Output

Success

$ envcheck

✓ Tools
  ✓ rustc: 1.75.0 (>= 1.65.0)
  ✓ cargo: installed

✓ Environment Variables
  ✓ RUST_LOG: info
  ✓ DATABASE_URL: ***

✓ Files
  ✓ Cargo.toml: exists
  ✓ src/main.rs: exists
  ✓ src/lib.rs: not found (optional)

All checks passed!

Tips for Rust Projects

Update your Rust toolchain easily with rustup update. Use rustup show to see your current installed versions.

If DATABASE_URL is required for compile-time query checking with SQLx, mark it as required: true and set it even in development.

The configuration checks for both src/main.rs and src/lib.rs as optional, making it suitable for both binary and library projects.

Common Variations

Web API with Actix/Axum

Add web framework requirements:

env_vars:
  - name: RUST_LOG
    required: true
    pattern: "^(trace|debug|info|warn|error)$"
  - name: DATABASE_URL
    required: true
  - name: HOST
    required: false
  - name: PORT
    required: false

ports:
  - 8080

files:
  - path: Cargo.toml
    required: true
  - path: src/main.rs
    required: true

SQLx Database Project

Ensure SQLx compile-time checks work:

tools:
  - name: rustc
    version: ">=1.65.0"
    required: true
  - name: cargo
    required: true
  - name: sqlx-cli
    required: true

env_vars:
  - name: DATABASE_URL
    required: true  # Required for compile-time query verification

files:
  - path: migrations
    required: true
  - path: .sqlx
    required: false

Embedded/No-Std Project

Validate cross-compilation toolchain:

tools:
  - name: rustc
    version: ">=1.65.0"
    required: true
  - name: cargo
    required: true
  - name: arm-none-eabi-gcc
    required: true

files:
  - path: Cargo.toml
    required: true
  - path: memory.x
    required: true
  - path: .cargo/config.toml
    required: true

Workspace Setup

For multi-crate workspaces:

files:
  - path: Cargo.toml
    required: true
  - path: Cargo.lock
    required: true

tools:
  - name: rustc
    version: ">=1.65.0"
    required: true
  - name: cargo
    required: true
  - name: cargo-workspaces
    required: false

WASM Target

Validate WebAssembly toolchain:

tools:
  - name: rustc
    version: ">=1.65.0"
    required: true
  - name: cargo
    required: true
  - name: wasm-pack
    required: true

files:
  - path: Cargo.toml
    required: true
  - path: src/lib.rs
    required: true

Rust-Specific Considerations

Logging Levels

RUST_LOG accepts various formats:

• Simple: info, debug, trace
• Module-specific: my_crate=debug,hyper=info
• Complex filters: warn,my_crate::module=trace

Database URL Format

Common DATABASE_URL patterns:

• PostgreSQL: postgres://user:pass@localhost/db
• MySQL: mysql://user:pass@localhost/db
• SQLite: sqlite://path/to/db.sqlite or sqlite::memory:

Cargo Configuration

Consider checking .cargo/config.toml for projects with custom build configurations, target specifications, or registry settings.

Learn More

• Tools Validator - Rust toolchain and cargo tools
• Environment Variables - Runtime configuration
• File Validator - Project structure validation
• Port Checker - Service port management