You may want to use kubernetes-secret-generator. I've tested it and it's doing exactly what you need.
To accomplish it you have to have helm in your cluster and follow these instructions:
Clone repository
$ git clone https://github.com/mittwald/kubernetes-secret-generator
Create helm deployment
$ helm upgrade --install secret-generator ./deploy/chart
Now you to use it, you just have to
Add annotation secret-generator.v1.mittwald.de/autogenerate
to any
Kubernetes secret object .The value of the annotation can be a field
name (or comma separated list of field names) within the secret; the
SecretGeneratorController will pick up this annotation and add a field
[or fields] (password
in the example below) to the secret with a
randomly generated string value. From here.
$ kubectl apply -f mysecret.yaml
apiVersion: v1
kind: Secret
metadata:
name: mysecret
annotations:
secret-generator.v1.mittwald.de/autogenerate: password
data:
username: UGxlYXNlQWNjZXB0Cg==
After applying this secret you can take a look at it to check if the passward was generated as expected:
$ kubectl get secrets mysecret -o yaml
apiVersion: v1
data:
password: dnVKTDBJZ0tFS1BacmtTMnBuc3d2YWs2YlZsZ0xPTUFKdStDa3dwUQ==
username: UGxlYXNlQWNjZXB0Cg==
kind: Secret
metadata:
annotations:
kubectl.kubernetes.io/last-applied-configuration: |
{"apiVersion":"v1","data":{"username":"UGxlYXNlQWNjZXB0Cg=="},"kind":"Secret","metadata":{"annotations":{"secret-generator.v1.mittwald.de/autogenerate":"password"},"name":"mysecret","namespace":"default"}}
secret-generator.v1.mittwald.de/autogenerate: password
secret-generator.v1.mittwald.de/autogenerate-generated-at: 2020-01-09 14:29:44.397648062
+0000 UTC m=+664.011602557
secret-generator.v1.mittwald.de/secure: "yes"
creationTimestamp: "2020-01-09T14:29:44Z"
name: mysecret
namespace: default
resourceVersion: "297425"
selfLink: /api/v1/namespaces/default/secrets/mysecret
uid: 7ae42d71-32ec-11ea-92b3-42010a800009
type: Opaque
As we can see, the password was generated and it's encrypted as you need.