Merge LogGroup Resources, even when no Role resources were merged

[eahefnawy]

What did you implement:

Closes #3174

Fixed a bug where LogGroup resources are not created if all your functions use custom roles.

How did you implement it:

Moved the logic that adds LogGroups resources at the top of the merge method, so that they're always merged, even when no roles are merged, like in the case of custom roles.

How can we verify it:

Using this config:

service: log-group-bug

provider:
  name: aws

functions:
  hello:
    role: something
    handler: handler.hello

  world:
    role: somethingelse
    handler: handler.world

All functions use custom roles, so no role resources are added. Run sls deploy --noDeploy and you'll see that the roles resources are not added, while the LogGroup resources are added.

Todos:

• Write tests
• Write documentation
• Fix linting errors
• Make sure code coverage hasn't dropped
• Provide verification config / commands / resources
• Enable "Allow edits from maintainers" for this PR
• Update the messages below

Is this ready for review?: YES
Is it a breaking change?: NO

[pmuens]

Tested it with the following config:

service: service

provider:
  name: aws
  runtime: nodejs4.3

functions:
  hello:
    handler: handler.hello
    role: foo

The LogGroup resource is created, but also the Role for the function (which I think should be fine):

"HelloLambdaFunction": {
      "Type": "AWS::Lambda::Function",
      "Properties": {
        "Code": {
          "S3Bucket": {
            "Ref": "ServerlessDeploymentBucket"
          },
          "S3Key": "serverless/service/dev/1486634119276-2017-02-09T09:55:19.276Z/service.zip"
        },
        "FunctionName": "service-dev-hello",
        "Handler": "handler.hello",
        "MemorySize": 1024,
        "Role": {
          "Fn::GetAtt": [
            "foo",
            "Arn"
          ]
        },
        "Runtime": "nodejs4.3",
        "Timeout": 6
      },
      "DependsOn": [
        "foo"
      ]
    },

Maybe I'm missing smth. but this shouldn't be the case according to this comment in the PR description:

All functions use custom roles, so no role resources are added. Run sls deploy --noDeploy and you'll see that the roles resources are not added, while the LogGroup resources are added.

According to the tests you mean that this role is not added (which I can confirm is not added):

getRoleLogicalId() {
    return 'IamRoleLambdaExecution';
  },

[eahefnawy]

@pmuens yep sorry for the confusion there. I mean the default role resource is not added. But of course the custom role is added, otherwise the function wouldn't have any permissions at all. So the output you're seeing is what's expected.

[pmuens]

@eahefnawy Ok, got it. That's what I would expect as well... Merging this now since it resolves the issue!