Allow SNSSQS MessageGroupId to be set programatically via pubsub metadata

[Jossec101]

Describe the feature

We have a business logic which requires to be able to take advantage of the MessageGroupId to be set programatically as we want to do FIFO parallel consumption but sequentially based on the same MessageGroupId groups.

I guess that adding a flag in the metadata and modifying something like FifoMessageGroupId key and checking if set, use it as a the result var for the function could make it.

We can do the PR work ;)

components-contrib/pubsub/aws/snssqs/snssqs.go

Lines 371 to 380 in f99604f

	func (s *snsSqs) getMessageGroupID(req *pubsub.PublishRequest) *string {
	if len(s.metadata.FifoMessageGroupID) > 0 {
	return &s.metadata.FifoMessageGroupID
	}
	// each daprd, of a given PubSub, of a given publisher application publishes to a message group ID of its own.
	// for example: for a daprd serving the SNS/SQS Pubsub component we generate a unique id -> A; that component serves on behalf
	// of a given PubSub deployment name B, and component A publishes to SNS on behalf of a dapr application named C (effectively to topic C).
	// therefore the created message group ID for publishing messages in the aforementioned setup is "A:B:C".
	fifoMessageGroupID := fmt.Sprintf("%s:%s:%s", s.id, req.PubsubName, req.Topic)
	return &fifoMessageGroupID

The code could look like this:

func (s *snsSqs) getMessageGroupID(req *pubsub.PublishRequest) *string {
	// if the request has provided a messageGroupID in the metadata, use it.
	if req.Metadata["messageGroupID"] != "" {
		fifoMessageGroupID := req.Metadata["messageGroupID"]
		return &fifoMessageGroupID
	}

	if len(s.metadata.FifoMessageGroupID) > 0 {
		return &s.metadata.FifoMessageGroupID
	}

	// each daprd, of a given PubSub, of a given publisher application publishes to a message group ID of its own.
	// for example: for a daprd serving the SNS/SQS Pubsub component we generate a unique id -> A; that component serves on behalf
	// of a given PubSub deployment name B, and component A publishes to SNS on behalf of a dapr application named C (effectively to topic C).
	// therefore the created message group ID for publishing messages in the aforementioned setup is "A:B:C".
	fifoMessageGroupID := fmt.Sprintf("%s:%s:%s", s.id, req.PubsubName, req.Topic)
	return &fifoMessageGroupID
}

Release Note

RELEASE NOTE: ADD SNSSQS FifoMessagroupId can be set programatically via pubsub req metadata.

[berndverst]

@Jossec101 sounds good - can you comment here with /assign please? This of course cannot be released until Dapr 1.14

[berndverst]

One complication factor: You also should cover the new functionality in our integration test (certification test) here: https://github.com/dapr/components-contrib/tree/main/tests/certification/pubsub/aws/snssqs

Writing the test and verifying that everything works (e.g. calling the AWS SDK manually to check it worked on the server) is the hardest part here.