• Kubernetes local cluster (use: k3d, minikube etc.)
• Skaffold to easily deploy the sample app in local kubernetes, Installing Skaffold
• mirrord as a tool to develop service locally as if it is inside kubernetes cluster, Introduction

This section we're going to setup our sample cluster the scenario is that we already have a running service that we're developing.

To make it easy use skaffold so that we don't have to publish any container image in order to run it on cluster.

Deploy this project to local kubernetes using skaffold

skaffold run

You can observe that if successful a running pod will appear in cluster

In this case pretend that you have uncommitted code changes and want to test it on the cluster.

Next, we're going to run this service locally using mirrord, the target pod name can be copied from the cluster

mirrord exec --target pod/my-server-74cd947f55-lpqdq go run .

If there's no error, http port 8080 will be accessible and you can hit the endpoint localhost:8080/api/get_pods to test

curl localhost:8080/api/get_pods | json_pp

The endpoint serve by this sample app will return a list of pods inside the cluster, this shows that the local service is actually running as if it is inside the cluster

API response something like:

{
   "message" : "get pods successful, there are 9 pods",
   "pods" : [
      ...
      {
         "name" : "my-server-74cd947f55-lpqdq",
         "namespace" : "default"
      },
      {
         "name" : "mirrord-agent-zkjdyl9ffi-f8p47",
         "namespace" : "default"
      },
      ...
   ]
}

If you look closer to how mirrord works, it actually spawn a kubernetes job and run a mirrord agents pod to communicate with the target pod.