Mirror a kubernetes environment locally
Kubernetes encourages microservices. That's a great development pattern, but sometimes debugging can be difficult because you need to run multiple services to work on or test functionality.
One approach is to setup a local Kubernetes cluster with a tool like minikube which can hold a local version of every service in your production cluster. Unfortunately it can sometimes be cumbersome to setup, and it's easy to let your local cluster drift from what's in your production environment. Also, if you need to switch between deployments in two different clusters you'll have a hard time doing that.
kube-mirror lets you get back to basics. Run the service you're trying to debug locally, using npm start directly. It works by calling kubectl port-forward using your currently configured kubectl context to expose local ports. kube-mirror also puts entries into your hosts file so that your local service can connect to mirrored services as if it were in the cluster.
Note: kube-mirror will allow your local service to interact with remote services. It will not allow remote services to make requests to your local services.
npm install -g kube-mirror
Note: Installation will require sudo on some systems for the ability to modify hosts files.
You'll need to create a configuration file that lets kube-mirror know some information about your cluster
example:
name: prod
services:
mongo:
port: 27017
redis:
name: redis-deployment
port: 51235
localPort: 6543
app:
port: 9999
pods:
- name: mypod-21s25a
port: 5210Once that's setup, you can load the config into kube-mirror
kube-mirror load ./mirror-config.yaml
kube-mirror only stores the path to your config file, so updates will be automatically reflected
Mirror an entire environments
kube-mirror mirror prod
If you're debugging a specific service locally, you may want to omit it from the mirror
kube-mirror mirror prod --omit mongo,app
Once you're done debugging a given environment, you can clean up your hosts file using:
kube-mirror remove prod