Awsm Env

A lightweight utility for syncing AWS Secrets Manager secrets to environment variables.

Go from an .env.example file like this:

# This directive loads the value from a secret named 'production/database-url'
# @aws production/database-url
DATABASE_URL=

# Use placeholders with `$`
# @aws $environment/api/secret
API_SECRET=

# Default values are preserved when no directive is present
PORT=3000

to this:

DATABASE_URL="postgres://user:pass@example.com/foobar"
API_SECRET="your-api-secret-from-aws"
PORT=3000

Installation

Cargo

Install the awsm-env crate using Cargo:

cargo install awsm-env

Usage

Ensure AWS credentials are properly configured through:

• Environment variables (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY)
• AWS credentials file (~/.aws/credentials)
• IAM roles for EC2/ECS instances

# Basic usage - reads from .env.example and outputs to stdout in env format
awsm-env

# Use a different example file
awsm-env path/to/my-env-spec.txt

# Write output to a file instead of stdout
awsm-env -o .env.production

# Override values
awsm-env --var API_KEY=abc123 --var DEBUG=true

# Add placeholders for secret names
awsm-env --placeholder ENVIRONMENT=production --placeholder DEBUG=true

# Export variables directly into the shell
$(awsm-env --f shell)

# Output in JSON format
awsm-env -f json

# Don't use defaults from the spec file
awsm-env --no-defaults

Secrets

Specify AWS Secrets Manager sources with comments beginning with @aws:

# @aws production/database-url
DATABASE_URL=

Placeholders

Use placeholders to manage multiple environments:

# @aws $environment/database-url
DATABASE_URL=

Specify the placeholder when running awsm-env.

awsm-env -p environment=staging

This makes it easy to switch between environments:

# Development
awsm-env -p environment=dev -o .env

# Staging
awsm-env -p environment=staging -o .env

# Production
awsm-env -p environment=production -o .env

Overrides

Override or add values directly with the --var flag.

If you have an .env.example file like this:

# @aws production/database-url
DATABASE_URL=

# @aws production/api/secret
API_SECRET=

PORT=3000

Running the following:

awsm-env .env.example \
    --var API_SECRET=1234 \
    --var PORT=8080 \
    --var LOG_LEVEL=debug

will produce:

DATABASE_URL="<secret from aws>"

# The following values are overriden
API_SECRET="1234"
PORT="8080"
LOG_LEVEL="debug"

Output

By default, awsm-env prints to stdout. Use -o to write to a file instead.

Choose from multiple output formats with the -f flag:

Defaults

By default, awsm-env preserves default values from the source file. Disable this behavior with --no-defaults to only include values from AWS or overrides.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

Prerequisites:

• Rust 1.85.1

Set up pre-commit hooks using cargo-husky:

cargo test

Development workflow:

# Run in development mode
cargo run

# Run test suite
cargo test

# Build release version
cargo build --release

License

MIT