secrets

Recently I needed to mount an SSH private key used for one app to connect to another app into a running Pod, but to make sure it was done securely, we put the SSH key into a Kubernetes Secret, and then mounted the Secret into a file inside the Pod spec for a Deployment.

I wanted to document the process here because (a) I know I'm going to have to do it again and this will save me a few minutes' research, and (b) it's very slightly unintuitive (at least to me).

First I defined a secret in a namespace:

Update: In the comments, the following one-liner is suggested by Matt T if you have jq installed (a handy utility if there ever was one!):

kubectl get secret my-secret -o json | jq '.data | map_values(@base64d)'

I figured it would be handy to have a quick reference for this, since I'll probably forget certain secrets many, many times in the future (I'm like that, I guess):

I have a Kubernetes Secret used for Traefik ingress basic HTTP authentication (using annotation ingress.kubernetes.io/auth-secret), and as an admin with kubectl access, I want to see (or potentially modify) its structure.

Let's say the Secret is in namespace testing, and is named test-credentials. To get the value of the basic auth credentials I do:

kubectl get secret test-credentials -n testing -o yaml

This spits out the Kubernetes object definition, including a field like:

data:
  auth: [redacted base64-encoded string]

So then I copy out that string and decode it: