[FEATURE] Google Pub/Sub describe bse64 encoded payload

[freaz]

Why do we need this improvement?

As payload we are sending base64 encoded JSON. So I need to be able to document what schema it has, and also tell it must be encoded as base64 string for transport.

Message bindings show only examples for Protobuf and Avro.
What is the best way to document any base64 encoded string?

Best I could come up with is to use contentType: application/json; encoding=base64. Full example: google-pubsub-asyncapi.yaml.

I wanted to usebindings.googlepubsub.schema.encoding: json, but I don't have schema validations when publishing messages to topic.

Original Slack question

How will this change help?

Allows to define any payload when base64 encoded, as is required by Google Pub/Sub.

Screenshots

No response

How could it be implemented/designed?

I don't know.

🚧 Breaking changes

No

👀 Have you checked for similar open issues?

• I checked and didn't find a similar issue

🏢 Have you read the Contributing Guidelines?

• I have read the Contributing Guidelines

Are you willing to work on this issue?

None

[github-actions]

Welcome to AsyncAPI. Thanks a lot for reporting your first issue. Please check out our contributors guide and the instructions about a basic recommended setup useful for opening a pull request.
Keep in mind there are also other channels you can use to interact with AsyncAPI community. For more details check out this issue.

[derberg]

CC @whitlockjc