initializing-deployments-based-on-metadata.md

Initializing Deployments Based On Metadata

It's possible to select which objects are initialized using metadata. In this section the Envoy Initializer will be redeployed and configured to only initialize Deployments with an initializer.kubernetes.io/envoy annotation set to a non-empty value.

Prerequisites

Delete the existing helloworld and envoy-initializer Deployments:

kubectl delete deployments helloworld envoy-initializer

Deploy the Envoy Initializer

Deploy the Envoy Initializer with the -require-annotation flag set. This will ensure the Envoy proxy container is only injected into Deployments with an initializer.kubernetes.io/envoy annotation set to a non-empty value.

kubectl apply -f deployments/envoy-initializer-with-annotation.yaml

Create the helloworld Deployment:

kubectl apply -f deployments/helloworld.yaml 

Notice the helloworld Deployment has been initialized without injecting the Envoy proxy container:

kubectl get pods

NAME                                READY     STATUS    RESTARTS   AGE
envoy-initializer-460025406-f56d4   1/1       Running   0          56s
helloworld-3116035291-6nl6x         1/1       Running   0          10s

Create the helloworld-with-annotation Deployment

kubectl apply -f deployments/helloworld-with-annotation.yaml

Notice the helloworld-with-annotation Deployment has been initialized with the Envoy proxy container:

kubectl get pods

NAME                                          READY     STATUS    RESTARTS   AGE
envoy-initializer-460025406-f56d4             1/1       Running   0          7m
helloworld-3116035291-6nl6x                   1/1       Running   0          6m
helloworld-with-annotation-3482720967-8b2qr   2/2       Running   0          6s