How to insert or add a field in a yaml after a specific key in yq

Question

I have a k8s yaml file with below block

spec:
  replicas: 1
  strategy:
    type: Recreate

and I want to add below block after "spec:"

selector:
  matchLabels:
    app: test-app

The file is huge and has many "spec:" fields, so it should be added at the first match.

Final file content should look like this :

spec:
  selector:
    matchLabels:
      app: test-app
  replicas: 1
  strategy:
    type: Recreate

I came up with this working solution using yq with correct indentation but it appends at the end of the file, Its painful to maintain and reading similar 100's of files.

yq  -i -y '.spec += {selector:{matchLabels:{app:"test-app"}}}' filename.yaml

Any answers with tools like sed or awk are welcome.

Answer 1

Here you go

$ yq --yaml-output '.spec |= ({selector: {matchLabels: {app: "test-app"}}} + .)' </tmp/your-yaml-file.yaml 

spec:
  selector:
    matchLabels:
      app: test-app
  replicas: 1
  strategy:
    type: Recreate

Since you mentioned you have hundreds of files and each has many spec elements, it's unclear if this will solve your actual problem but hopefully it can be of help. Good luck!