Red Hat OpenShift Container Platform

Understanding secrets

You can mount secrets into containers by using a volume plugin or the system can use secrets to perform actions on behalf of a pod.

The Secret object type provides a mechanism to hold sensitive information such as passwords, Red Hat OpenShift Container Platform client configuration files, private source repository credentials, and so on. Secrets decouple sensitive content from the pods.

Key properties include:

Secret data can be referenced independently from its definition.
Secret data volumes are backed by temporary file-storage facilities (tmpfs) and never come to rest on a node.
Secret data can be shared within a namespace.

YAML Secret object definition

apiVersion: v1
kind: Secret
metadata:
  name: test-secret
  namespace: my-namespace
type: Opaque
data:
  username: <username>
  password: <password>
stringData:
  hostname: myapp.mydomain.com

where:

type: Specifies the structure of the secret’s key names and values.
data: Specifies the allowable format for the keys in the data field must meet the guidelines in the DNS_SUBDOMAIN value as described in "Identifiers and Names in Kubernetes" in the Kubernetes documentation.
data.username: Specifies the value associated with keys in the data map. This value must be base64 encoded.
data.password: Specifies the value associated with keys in the data map. This value must be base64 encoded.
stringData.hostname: Specifies the value associated with keys in the data map. The value associated with keys in the stringData map is made up of plain text strings. Entries in the stringData map are converted to base64 and the entry will then be moved to the data map automatically. This field is write-only; the value will only be returned via the data field.

You must create a secret before creating the pods that depend on that secret.

When creating secrets:

Create a secret object with secret data.
Update the pod’s service account to allow the reference to the secret.
Create a pod, which consumes the secret as an environment variable or as a file (using a secret volume).