feat: optionally set warmer roleName if using default role

[OffensiveBias-08-145]

Optionally set a roleName for the warmers.

Use Case:

Sometimes the default generated Role name exceeds the IAM max name length of 64 characters.

This causes deployments to fail for some users if they do not disable the warmers for deployments.

Example:

Error:
CREATE_FAILED: WarmUpPluginDefaultRole (AWS::IAM::Role)
1 validation error detected: Value 'apple-map-api-sandbox-ap-south-1-stack-sandbox-ap-south-1-default-role' at 'roleName' failed to satisfy constraint: Member must have length less than or equal to 64 (Service: AmazonIdentityManagement; Status Code: 400; Error Code: ValidationError; Request ID: 60b62c0f-18d8-4b63-80fe-672b1b5d8add; Proxy: null)

Cause:

serverless-plugin-warmup/src/warmer.js

Lines 25 to 40 in 847b45c

	service.resources.Resources[warmerConfig.role] = {
	Type: 'AWS::IAM::Role',
	Properties: {
	Path: '/',
	RoleName: {
	'Fn::Join': [
	'-',
	[
	service.service,
	stage,
	{ Ref: 'AWS::Region' },
	warmerName.toLowerCase(),
	'role',
	],
	],
	},

Fix:

Optionally provide warmer RoleName field for two main reasons:

1. Allow users to follow a specific naming structure across their accounts
2. Provide a workaround for the max character limit for IAM Role names.

---

Please let me know if I have missed anything... Thanks!

[OffensiveBias-08-145]

@juanjoDiaz Please let me know if I left out any contribution steps or if there are any test cases you feel need to be added.

[juanjoDiaz]

Thanks for the very complete PR.

It's much appreciate when a PR describes well the reasoning behind it and it follows the style, includes tests and a good commit description 🙂

Just a couple of minor changes in the docs requested

[juanjoDiaz]

It seems that coverage is going down.

Can you check npm run test-with-coverage and investigate what is not being covered?

[OffensiveBias-08-145]

It seems that coverage is going down.

Can you check npm run test-with-coverage and investigate what is not being covered?

Seems as though L:32 of warmer.js is uncovered. I tried adding a test for coverage if the roleName was undefined but it seems to have not resolved the issue.

serverless-plugin-warmup/src/warmer.js

Lines 28 to 40 in c9c3437

	Path: '/',
	RoleName: warmerConfig.roleName ? warmerConfig.roleName : {
	'Fn::Join': [
	'-',
	warmerConfig.roleName ? [warmerConfig.roleName]
	: [
	service.service,
	stage,
	{ Ref: 'AWS::Region' },
	warmerName.toLowerCase(),
	'role',
	],
	],

Any thoughts?

[icholy]

Nice, I just ran into this issue too.

[juanjoDiaz]

Sorry for the delay.
This is almost there.

Just a small issue captured by test coverage.
Once you fix it this is good to go.