kubernetes update secrets using imperative commands

Question

I am creating kubernetes secrets using the below command

kubectl create secret generic test-secret --save-config --dry-run=client --from-literal=a=data1 --from-literal=a=data2 -o yaml | kubectl apply -f -

Now, I need to add new literals using kubectl imperative command how to do that?? say eg:

kubectl apply secret generic test-secret  --from-literal=c=data3 -o yaml | kubectl apply -f -

but gave the below error

Error: unknown flag: --from-literal See 'kubectl apply --help' for usage. error: no objects passed to apply

Any quick help is appreciated

score 1 · Answer 1 · answered Mar 28 '21 at 06:45

add new literals using kubectl imperative command

When working with imperative commands it typically means that you don't save the change in a place outside the cluster. You can edit a Secret in the cluster directly:

kubectl edit secret test-secret

But if you want to automate your "addition", then you most likely save your Secret another place before applying to the cluster. How to do this depends on how you manage Secrets. One way of doing it is by adding it to e.g. Vault and then have it automatically injected. When working in an automated way, it is easier to practice immutable Secrets, and create new ones instead of mutating - because you typically need to redeploy your app as well, to make sure it uses the new. Using Kustomize with secretGenerator might be a good option if you work with immutable Secrets.

Thanks Jonas, I am planning to use sealed secrets... https://github.com/bitnami-labs/sealed-secrets. Thinking of a way to automate the literals to the existing secrets. — magic, Mar 28 '21 at 09:34
They have documentation on https://github.com/bitnami-labs/sealed-secrets#update-existing-secrets — Jonas, Mar 28 '21 at 09:54

Girdhar Singh Rathore · Answer 2 · 2021-03-28T14:19:27.690

You can use `kubectl patch` imeperative command

example

    root@controlplane:~# kubectl patch secrets test-secret --type='json' -p='[{"op" : "replace" ,"path" : "/data/newkey" ,"value" : "bmV3VmFsCg=="}]'
    secret/test-secret patched
    root@controlplane:~# kubectl describe secrets test-secret 
    Name:         test-secret
    Namespace:    default
    Labels:       <none>
    Annotations:  <none>

    Type:  Opaque

    Data
    ====
    a:       5 bytes
    b:       5 bytes
    newkey:  7 bytes

you need to pass encoded value, to encode/decode the new value of key you can use below command

root@controlplane:~# echo "newValue" | base64
bmV3VmFsdWUK
root@controlplane:~# echo bmV3VmFsdWUK | base64 -d
newValue

another option is to use kubectl edit but if you automate your code you can't use edit option

kubectl edit secret test-secret

kubernetes update secrets using imperative commands

2 Answers2

You can use kubectl patch imeperative command

You can use `kubectl patch` imeperative command