View and modifies Kubernetes secret

View

For encoded values.yaml key

kubectl -n $namespace get secret $secret -o yaml | awk '/values.yaml/ {print $2}' | base64 --decode > secret.yaml

Modify

Make changes to secret.yaml, then

kubectl -n $namespace patch secret $secret -p '{"data": {"values.yaml": "'''$(base64 -w 0 secret.yaml)'''"}}'

note Avoid newlines The -w 0/--wrap=0 argument tells base64 to not wrap the encoded lines after a certain number of characters. If you leave this off, the string gets a newline inserted every 76 characters and kubectl will puke when trying to parse it.