Kubernetes: Apply parts of a manifest by labels

2 min read | by Jordi Prats

Sometimes we might have a manifest file with a lot of objects in it but we don't really need them all. We can use it's labels to install just the objects that have a specific label.

Let's assume we have the following manifest:

kind: Service apiVersion: v1 metadata:  name: demo1  labels:  app: first spec:  type: ExternalName  externalName: demo1.pet2cattle.com --- kind: Service apiVersion: v1 metadata:  name: demo2  labels:  app: second spec:  type: ExternalName  externalName: demo2.pet2cattle.com 

If we apply it as usual it's going to create both objects:

$ kubectl apply -f test_en.yaml service/demo1 created service/demo2 created 

But with the -l option we can specify the label that's going to be used to filter the objects. So for example if we set it to app=first it's going to apply just the object that has that label, in the example that would be demo1:

$ kubectl apply -f test_en.yaml -l app=first service/demo1 created 

We can do the same using app=second to install just the other object as well:

$ kubectl apply -f test_en.yaml -l app=second service/demo2 created 

Posted on 15/09/2022