Add an example of how to use patch.

[brendandburns]

See #443 (comment)

[danquah]

Just to make sure I understand this before looking into doing an example.

Lets take the example from #443 (comment)

 const k8sNetworkingApi = kc.makeApiClient(k8s.NetworkingV1beta1Api);
  const patchedIngress = {
    metadata: {
      annotations: {
        'nginx.ingress.kubernetes.io/cors-allow-origin': '*'
      }
    }
  }

  // The following gets rejected with a 
  // "Unsupported Media Type":
  //    the body of the request was in an unknown format - 
  //    accepted media types include: application/json-patch+json, 
  //    application/merge-patch+json, application/apply-patch+yaml
  k8sNetworkingApi.patchNamespacedIngress(ingressName, namespace, patchedIngress);

  // The fix is to do this:
  k8sNetworkingApi.patchNamespacedIngress(ingressName, namespace, patchedIngress, undefined, undefined, undefined, undefined,
    { headers: { 'content-type': 'application/merge-patch+json' } });

The problems boils down to this (again, as I understand it).

• The generated openapi client code does not explicitly set a Content-Type for the PATCH request
• The client code does set json: true causing request (the library) to set Content-Type: application/json
• the api-server subsequently rejects the PATCH as it requires another Content-Type, eg. application/merge-patch+json

So, in other words: the generated client code that does the PATCH is incompatible with the api-server out of the box, and the (for this repo) official way of fixing this is to always provide the optional options argument and manually set the Content-Type header?

[saxicek]

@danquah Exactly. That is why I asked for the example - client code does not work out of the box, optional parameter which specifies content-type must be included. In my opinion it is fine to force developers to specify this explicitly - in my case it lead me to study various merge types in Kubernetes (https://www.disasterproject.com/kubernetes-kubectl-patching/). But it should be documented.

[mauriziovitale]

@brendanburns Same here, I am not able to patch a container image.

It works just fine when I run it from postman:
curl -X PATCH \ https://domain/api/v1/namespaces/namespace/pods/process-697548b7b4-d2hgn \ -H 'Content-Type: application/json-patch+json' \ -d '[{"op": "replace", "path": "/spec/containers/0/image", "value":"new image"}]'

It looks like we are suffering the same issue of kubernetes-client/python#866