Istio 101 : How is the envoy proxy side car added to our pods/deployments
Istio uses kubernetes admission webhooks to add a sidecar into an existing deployment of pods.
We start by going into the istio namespace where we want to add the envoy side car - to the pods living in that namespace - using the below command:
All the subsequent "kubectl" commands will take place in the namespace listed in the context "istio-context".
The "config" file has the following format:
We create a deployment of pods in our namespace "istio-ns", and we check if the envoy proxy sidecar was added to our pods.
Below is our simple deployment example:
Then we check the Yaml file of one of the deployed pods using the below command which outputs the definition of the pod in a Yaml format:
We get our pod's name using the "kubectl get pods" command.
Below is our updated Yaml file of our pod:
The "istio-sidecar-injector" mutating admission webhook is responsible for adding the proxy side car to our pods.
To check it, we could use the below command: