doc(k8s): add in/out cluster api querying procedure

misc/k8s/README.md

@@ -41,6 +41,8 @@ By default, with you host web browser, open http://localhost:9000, you should se
 
 ### Using the admin API
 
+#### From inside the cluster
+
 1. Open shell in bouncer-admin pod
 
    ```shell
@@ -59,6 +61,20 @@ By default, with you host web browser, open http://localhost:9000, you should se
    bouncer admin proxy query
    ```
 
+#### From outside the cluster
+
+1. Retrieve the authentication token from the generated secret
+
+   ```shell
+   TOKEN=$(kubectl get secret -n bouncer-dev -o jsonpath="{.data.token}" bouncer-admin-writer-token | base64 -d)
+   ```
+
+2. Use the `bouncer` admin client to query the admin API
+
+   ```shell
+   ./bouncer admin proxy query -t "${TOKEN}" --server http://127.0.0.1:9999
+   ```
+
 ## Benchmarking
 
 You can use [`siege`](https://github.com/JoeDog/siege) to benchmark your instance with the Cadoles proxy.