• A smart deployment command
• Shortcut aliases for common targets

When deploying applications, you often want to target different environments like staging, production, or development. A good deployment tool should be smart about defaults: when you don’t specify an environment, it could auto-detect based on context (like the current git branch), but when you explicitly choose one, it should respect that choice.

A smart deployment command

Let’s create a deploy command that auto-detects the environment when not specified, but uses the explicit value when provided:

@group()
def app():
    "Application management"

@app.command()
@option('--environment', '-e', default='staging', help='Target environment')
def deploy(environment):
    "Deploy the application"
    import click
    ctx = click.get_current_context()
    source = ctx.get_parameter_source('environment')

    if source.name == 'DEFAULT':
        print(f"No environment specified, auto-detecting...")
        print(f"Detected: production (from git branch)")
        print(f"Deploying to production")
    else:
        print(f"Environment explicitly set to: {environment}")
        print(f"Deploying to {environment}")

When called without the environment flag, it auto-detects:

clk app deploy

No environment specified, auto-detecting...
Detected: production (from git branch)
Deploying to production

When called with an explicit environment, it uses that:

clk app deploy --environment staging

Environment explicitly set to: staging
Deploying to staging

Shortcut aliases for common targets

To make deployments even more convenient, let’s create aliases for the most common targets:

clk alias set app.deploy-prod app deploy --environment production
clk alias set app.deploy-staging app deploy --environment staging

New global alias for app.deploy-prod: app deploy --environment production
New global alias for app.deploy-staging: app deploy --environment staging

The alias provides an explicit environment value, so the command correctly recognizes it as an explicit choice rather than falling back to auto-detection:

clk app deploy-prod

Environment explicitly set to: production
Deploying to production

This way, clk app deploy auto-detects while clk app deploy-prod always targets production.