CLI: Deprecate `sls deploy -f <function-name>`

[medikoo]

Use case description

There's a dedicated CLI command deploy function -f <function-name> for single function deployment. Still same can theoretically be achieved via deploy -f <function-name>.

It's problematic alias as both commands accept different options:

• serverless/lib/cli/commands-schema/aws-service.js

  Lines 10 to 36 in 712a569

  	options: {
  	'conceal': {
  	usage: 'Hide secrets from the output (e.g. API Gateway key values)',
  	type: 'boolean',
  	},
  	'package': {
  	usage: 'Path of the deployment package',
  	shortcut: 'p',
  	},
  	'verbose': {
  	usage: 'Show all stack events during deployment',
  	shortcut: 'v',
  	type: 'boolean',
  	},
  	'force': {
  	usage: 'Forces a deployment to take place',
  	type: 'boolean',
  	},
  	'function': {
  	usage: "Function name. Deploys a single function (see 'deploy function')",
  	shortcut: 'f',
  	},
  	'aws-s3-accelerate': {
  	usage: 'Enables S3 Transfer Acceleration making uploading artifacts much faster.',
  	type: 'boolean',
  	},
  	},

• serverless/lib/cli/commands-schema/aws-service.js

  Lines 52 to 65 in 712a569

  	'function': {
  	usage: 'Name of the function',
  	shortcut: 'f',
  	required: true,
  	},
  	'force': {
  	usage: 'Forces a deployment to take place',
  	type: 'boolean',
  	},
  	'update-config': {
  	usage: 'Updates function configuration, e.g. Timeout or Memory Size without deploying code',
  	shortcut: 'u',
  	type: 'boolean',
  	},

Also they're backed with different lifecycle events, therefore there's a wide room for both variants to not behave perfectly same.

Ideally we should drop support for sls deploy -f functioname

Proposed solution

1. Remove function option from schema of deploy command
2. Show deprecation if user invokes sls deploy --function. I believe it should be configured in deploy internal plugin, in newly introduced initialize hook

PR's welcome

[medikoo]

@pgrzesik let me know what you think about proposed solution

[jkklapp]

I'd like to take on this one if we have a green light on the proposal

[pgrzesik]

Thanks for proposal @medikoo - I fully agree that it's a problematic option. The proposal looks great, I don't have anything to add there.

[medikoo]

@jkklapp please do! We look forward