Kubernetes Secrets Operations

Internal

• Kubernetes Operations
• Cluster Configuration Concepts

Inspecting Secrets

kubectl get secrets

kubectl get secret mysecret -o yaml

The value of the secret is base64-encoded and it can be retrieved with:

echo '....' | base64 --decode

kubectl describe secret secret-name

Create a Secret

With kubectl CLI

Creating a Secret Using kubectl create secret

From File

Declare the secret content in one (or more) file(s) on the local filesystem. The file name will become a secret's data map key. Multiple files can be added to the same secret. When the secret is exposed to a pod, the content will be available as volume files with the same name.

echo -n "test-user" > ./username.txt
echo -p "test-password" > ./password.txt

kubectl create secret generic username-and-password --from-file=./username.txt --from-file=./password.txt

This will create the following secret:

Name:         username-and-password
Namespace:    test
Labels:       <none>
Annotations:  <none>

Type:  Opaque

Data
====
password.txt:  17 bytes
username.txt:  9 bytes

From Literal

The secret's data map key followed by "=" followed by value can be specified on command line with --from-literal=.

kubectl create secret generic red --from-literal=key1=somevalue --from-literal=key2=someothervalue

From Env File

A key-value (env) file can be used as source for secrets with --from-env-file=. The keys in the key-value file become the keys in the secret's data map.

kubectl create secret generic green --from-env-file=./test.txt

where test.txt:

key1=value1
key2=value2

Special Character Handling

Special characters such as '$', '*' and '!' require escaping (\).

From a Manifest

Creating a Secret Manually

TODO

The secret's data map key/value pairs can be specified in the manifest. The value must be base64-encoded before being written in the manifest.

apiVersion: v1
kind: Secret
metadata:
  name: blue
type: Opaque
data:
  shape: c3F1YXJl
  size: bGFyZ2U=

Alternatively, the values can be specified in clear as part of the "stringData" map; they will be encoded by Kubernetes when the secret is created:

apiVersion: v1
kind: Secret
metadata:
  name: blue
type: Opaque
stringData:
  shape: square
  size: large

Creating Secrets with a Generator

Creating a Secret from Generator

TODO

Consume a Secret

Consume a Secret as a File

kind: Pod
...
spec:
  containers:
  - name: ...
    volumeMounts:    
    - name: secret-volume
      mountPath: /etc/blue
      readOnly: true
  volumes:
  - name: secret-volume
    secret:
      secretName: blue