Apply part of kubernetes manifest yaml using kubectl

Question

consider the following kubernetes manifest (mymanifest.yml) :

apiVersion: v1
kind: Pod
metadata:
  name: firstpod
spec:
  containers:
  - image: nginx
    name: nginx
---
apiVersion: v1
kind: Pod
metadata:
  name: secondpod
spec:
  containers:
  - image: nginx
    name: nginx

If I do kubectl apply -f mymanifest.yml both pods are deployed. I remember someone told me that it is possible to deploy only one pod. Something like :

kubectl apply -f mymanifest.yml secondpod

But it doesn't work. Is there a way to do it?

Thx in advance

Answer 1

You can add labels to the pods

apiVersion: v1
kind: Pod
metadata:
  name: firstpod
  labels:
    app: firstpod
spec:
  containers:
  - image: nginx
    name: nginx
---
apiVersion: v1
kind: Pod
metadata:
  name: secondpod
  labels:
    app: secondpod
spec:
  containers:
  - image: nginx
    name: nginx

Use specific label to filter while applying the yaml. The filter supports =, ==, and !=

kubectl apply -f mymanifest.yml -l app=secondpod

You can also use --prune which is an alpha feature.

# Apply the configuration in manifest.yaml that matches label app=secondpod and delete all the other resources that are
not in the file and match label app=secondpod.
kubectl apply --prune -f mymanifest.yml -l app=secondpod