k8s-watcher

Kubernetes Watcher

This is a very simple tool that watches the endpoints of a Kubernetes service.

Pre-requisites

You need to have Docker installed.

Build and run

To build the binaries locally and run k8s-watcher outside of your container, type:

$ make build
$ ./k8s-watcher -kubeconfig=./my-kubeconfig.json -service=greeter-server -namespace=default
{"buildTag":"","buildTime":"","caller":"main.go:60","kubeconfig":"./kubeconfig.example.json","msg":"Watcher starting","namespace":"default","service":"greeter-server","ts":"2016-09-20T10:48:16+02:00","version":"dev"}
{"caller":"main.go:161","msg":"greeter-server: 172.17.0.2:50051, 172.17.0.3:50051\n","ts":"2016-09-20T10:48:21+02:00"}
{"caller":"main.go:161","msg":"greeter-server: 172.17.0.2:50051, 172.17.0.3:50051\n","ts":"2016-09-20T10:48:26+02:00"}
...

You can specify a kubeconfig file to configure connection settings. The kubeconfig.example.json is just an example of a kubeconfig file; use kubectl config view to get a list of all your current cluster configurations.

Start new pods of the service to see how k8s-watcher will find the new endpoints.

Build and run container

To build the Docker container and run it inside the Kubernetes cluster, type:

$ VERSION=0.1.0 make container
$ docker images | grep k8s-watcher
meplato/k8s-watcher       0.1.0               3d9ad5bc0927        2 seconds ago       31.4 MB

You can now run the image locally by using the deloyments/k8s-watcher.yaml file. Edit that file if you want different versions of k8s-watcher.

$ kubectl create -f deployments/k8s-watcher.yaml
$ kubectl get po --watch
... wait until the pod is ready
$ kubectl logs -f <k8s-watcher-pod>

To stop the watcher, run:

$ kubectl delete -f deployments/k8s-watcher.yaml

License

MIT