Adding a Web Handler Endpoint

Workflow

Copy this checklist and track your progress:

Creating or modifying a web endpoint:
- [ ] Step 1: Read local AGENTS.md file
- [ ] Step 2: Define in service.yaml
- [ ] Step 3: Generate Boilerplate Code
- [ ] Step 4: Move Implementation and Test if Renamed
- [ ] Step 5: Implement the Business Logic
- [ ] Step 6: Test the Web Handler
- [ ] Step 7: Document the Microservice
- [ ] Step 8: Versioning

Step 1: Read local AGENTS.md file

Check for and read a local AGENTS.md file in that microservice's directory. The local AGENTS.md file contains microservice-specific instructions that should take precedence over global instructions.

Step 2: Define in service.yaml

Define the web endpoint in the web array in the service.yaml of the microservice.

• The signature of the web endpoint must follow Go function syntax exactly. Do not include any input arguments nor any output arguments.
• The description should explain what the web endpoint is doing. It should start with the name of the web handler.
• A method restricts requests to a specific HTTP method such as GET, POST, DELETE, PUT, PATCH, OPTIONS or HEAD. The default ANY accepts all requests regardless of the method.

webs:
  - signature: MyNewWebHandler()
    description: MyNewWebHandler does X, Y and Z.
    method: ANY

Step 3: Generate Boilerplate Code

If you've made changes to service.yaml, run go generate to generate the boilerplate code.

Step 4: Move Implementation and Test if Renamed

If you made a change to the name of the web handler in the signature field, you need to move over its implementation in service.go from under the old name to the new name. Similarly, you'll need to move over the implementation of the tests in service_test.go.

Step 5: Implement the Business Logic

Look for the web handler declaration in service.go and implement or adjust its logic appropriately. Note that Microbus web handlers extend on the standard Go web handler signature by also returning an error. You do not need to worry about printing the error and status code to the http.ResponseWriter.

func (svc *Service) MyNewWebHandler(w http.ResponseWriter, r *http.Request) (err error) {
	// Implement logic here
	return err
}

Step 6: Test the Web Handler

Look for the integration test created in service_test.go for the web handler and implement or adjust it appropriately.

• Follow the pattern recommendation in the code
• Add downstream microservices or their mocks to the testing app

func TestMyservice_MyNewWebHandler(t *testing.T) {
	// Implement testing here
}

Step 7: Document the Microservice

Generate documentation for this microservice that captures its purpose, context, and design rationale. Focus on the reasons behind decisions rather than describing what the code does. Explain design choices, tradeoffs, and the context needed for someone to safely evolve this microservice in the future. Store the result in the microservice's local AGENTS.md file.

Step 8: Versioning

Run go generate to version the code.