Random order in mocks

[KoldoCanellas]

Hello, I am deploying Microcks!

When I deploy the same API specification (only changing the name), it seems that the order of the mocks is random. There seems to be another discussion with the same problem: https://github.com/orgs/microcks/discussions/1644

I would prefer not to have to create a script or fallback dispatcher. Is there a parameter that can be defined with OpenApi so that Microcks understands the priority?

[lbroudoux]

Hello @KoldoCanellas

Microcks will use your OpenAPI definition (especially the parameters) to infer a dispatcher and make the request/response matching predictable. See our explanations on dispatchers here: https://microcks.io/documentation/explanations/dispatching/

You can see it in action while walking through the "1st REST mock" tutorial here: https://microcks.io/documentation/tutorials/first-rest-mock/#3-using-query-parameters-in-openapi

Let me know if it helps.

[KoldoCanellas]

Thank you very much for your quick response @lbroudoux .

The case I am dealing with is a health endpoint like this:

openapi: 3.0.3
info:
  title: Test
  version: 3.0.0
  description: Test App
paths:
  /health:
    get:
      responses:
        "200":
          description: OK
          headers: {}
          content:
            application/json;charset=UTF-8:
              schema:
                type: object
                properties:
                  status:
                    type: string
              examples:
                health_ok:
                  value:
                    status: UP
        "500":
          description: Internal Server Error
          headers: {}
          content:
            application/json;charset=UTF-8:
              schema:
                type: object
                properties:
                  errorCode:
                    type: number
                  errorDescription:
                    type: string
              examples:
                internal_error:
                  value:
                    errorCode: 500
                    errorDescription: internal error
      summary: Health check endpoint
      operationId: Health
      tags: []
      parameters: []

I don't have any parameters like in the examples. How can I set the default to code 200?

[lbroudoux]

Ok, in that case, defining a dispatcher is required. But you can easily define it in your OpenAPI file using our extension, just adding a x-microcks-operation attribute like below:

openapi: 3.0.3
info:
  title: Test
  version: 3.0.0
  description: Test App
paths:
  /health:
    get:
      x-microcks-operation:
        dispatcher: JS
        dispatcherRules: 'return "health_ok"'
     [...]

If you're not using the latest 1.13.0 version, consider replacing the JS dispatcher above with SCRIPT. However, this won't work if you're using a native-compiled version of Microcks. JS with 1.13.0 will work everywhere though.

If you don't want to have this extension appear in your OpenAPI file, you can put this directive into an APIMetadataartifact. See https://microcks.io/documentation/references/metadada/

[KoldoCanellas]

Thank you very much for your quick response again.

It worked! Even if internal_error is set as a priority, it always returns 200.

Sending: ..../health
Receiving: {‘status’:‘UP’}

Thank you very much @lbroudoux .

[KoldoCanellas]

Hello again @lbroudoux !

I'm trying to implement something a little more complex.

I'm trying to get all possible responses. To do this, I want to add a header, for example, x-status-code.

The behaviour I want is that if I set the header, it responds with the status code that is set. For example, if I set -H 'x-status-code: 500', it returns the internal_error. But I want the default to be 200.

I have done this case here:

try {
  const testCase = mockRequest.getRequestHeader("x-status-code")[0];
  return "response_" + testCase;
} catch (error) {
  log.error("Error processing dispatcher rules: " + error);
  return "response_200";
}

when I set the header, it works fine, but when I don't set the header, it returns the priority from Microcks, it doesn't return 200, and it gives me that error 08:30:25.198 [ERROR] io.github.microcks.util.script.JsScriptEngineBinder - Error during JS evaluation java.lang.NullPointerException: Cannot invoke "java.util.List.iterator()" because the return value of "io.github.microcks.util.script.StringToStringsMap.get(Object)" is null

To see the behaviour, I have done a log.info and it gives an error and always returns 200.

try {
  log.info("Headers received: " + JSON.stringify(mockRequest.getRequestHeaders()));
  const testCase = mockRequest.getRequestHeader("x-status-code")[0];
  return "response_" + testCase;
} catch (error) {
  log.error("Error processing dispatcher rules: " + error);
  return "response_200";
}

And this gives me that error: 08:31:53.769 [ERROR] io.github.microcks.util.script.JsScriptEngineBinder - Error processing dispatcher rules: TypeError: not a function

Is this the desired behaviour? Because log.info does jump to the catch, but an error due to getRequestHeader does not jump to the catch.

[lbroudoux]

Yeah, the JS dispatcher is quite new and it looks like you hit methods that are not yet implemented on it. We have an open issue on this since yesterday, I think. Turning to GROOVY dispatcher should provide you the missing method while we're fixing the JS engine, though.

[lbroudoux]

Here's the issue: #1810