Updating kubernetes configmap secret without removing the existing one

Question

I'm using Kubernetes secret and configmap to manage our properties. I am using a design that keeps the property piles in a git repository and am using build server Toughtworks GO to automatically deploy it to my configmaps and secrets to my kubernetes cluster.

Right now, I've to delete the current configmap and secret to add the new ones to update:

step1: kubectl delete configmap foo

step2: kubectl create configmap foo --from-file foo.properties

Is there any other way to do this rather than deleting the old one to add new. Because it may damage the containers currently using the old configmaps if the new one hasn't been created yet.

Answer 1

You can fetch the YAML from kubectl, create configmaps command and the pipe the result to substitute kubectl:

kubectl create configmap foo --from-file foo.properties -o yaml --dry-run | kubectl replace -f -

Answer 2

The following command lets you update a complete configMap or even other objects.

kubectl replace -f file.yaml

Answer 3

You can use something like this:

# Replace a pod using the data in pod.json.
kubectl replace -f ./pod.json

# Replace a pod based on the JSON passed into stdin.
cat pod.json | kubectl replace -f -

# Update a single-container pod's image version (tag) to v4
kubectl get pod mypod -o yaml | sed 's/\(image: myimage\):.*$/\1:v4/' | kubectl replace -f -

# Force replace, delete and then re-create the resource
kubectl replace --force -f ./pod.json

Answer 4

You can use edit for small changes in configMap in the following way:

kubectl edit configmap <cfg-name>