docs: add instruction to generate openapi client (#138)

README.md

@@ -4,7 +4,6 @@ View and control Kamaji with a simple user interface from the web.
 
 ![Kamaji Console](.github/images/screen.png)
 
-
 ## Deploy on Kubernetes
 
 A sample manifest is available: `deploy/kamaji-console.yaml`. To deploy the console in the admin cluster, edit the manifest according to your environment and apply:
@@ -44,3 +43,25 @@ When reading child cluster resources, such as node, the console uses the TCP kub
 When running in dev mode, using `npm run dev`, the console uses raw kubeconfig to connect to the cluster, in this way you should check that the child kubernetes API are reachable from your local development tool.
 
 When build and deployed using docker, the console supposes to be runned inside parent kubernetes cluster, so it connects to the TCP using the tcp service fqdn in order to talk with child cluster kubernetes api.
+
+## Generating OpenAPI client from kubernetes Spec
+
+OpenAPI client can be generated using the [OpenAPI Generator](https://openapi-generator.tech) tool. See the [OpenAPI Generator](https://openapi-generator.tech/docs/installation) documentation for installation instructions.
+
+The console uses the OpenAPI client generated from the kubernetes spec to interact with the kubernetes API.
+
+First of all, you need access to a kubernetes cluster with kamaiji installed, and the kubernetes API exposed.
+
+To expose the kubernetes API, you can use the following command:
+
+```bash
+$ kubectl proxy --port=8080
+```
+
+Then, you can generate the OpenAPI client using the following command:
+
+```bash
+openapi-generator generate -g typescript-node  -i http://localhost:8080/openapi/v2 -o src/gen
+```
+
+The generated client will be placed in the `src/gen` directory.