khuedoan-homelab/docs/concepts/secrets-management.md

Secrets management

Overview

• Global secrets are stored in the global-secrets namespace.
• Integrate with GitOps using External Secrets Operator.
• Secrets that can be generated are automatically generated and stored in the global-secrets namespace.

!!! info

Despite the name _External_ Secrets Operator, global secrets are created in the same cluster and synced
to other namespaces using the [Kubernetes provider](https://external-secrets.io/latest/provider/kubernetes).

While not supported by default in this project, you can also use other external providers such as HashiCorp Vault,
AWS Secret Manager, Google Cloud Secret Manager, Azure Key Vault, 1Password, etc.

flowchart TD
  subgraph global-secrets-namespace[global-secrets namespace]
    secret-generator[Secret Generator] -- generate if not exist --> source-secrets[Source Secrets]
  end

  subgraph app-namespace[application namespace]
    ExternalSecret -- create --> Secret
    App -- read --> Secret
  end

  ClusterSecretStore -- read --> source-secrets
  ExternalSecret --- ClusterSecretStore

Randomly generated secrets

This is useful when you want to generate random secrets like admin password and store in global secrets.

--8<--
./platform/global-secrets/files/secret-generator/config.yaml
--8<--

Extra third-party secrets

For third-party secrets that you don't control, add them to external/terraform.tfvars under the extra_secrets key, then run make external.

They will be available as a Secret named external in the global-secrets namespace. You can use it with ExternalSecret just like any other global secret.

How secrets are pulled from global secrets to other namespaces

When you apply an ExternalSecret object, for example:

apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: gitea-admin-secret
  namespace: gitea
spec:
  data:
  - remoteRef:
      conversionStrategy: Default
      key: gitea.admin
      property: password
    secretKey: password
  refreshInterval: 1h
  secretStoreRef:
    kind: ClusterSecretStore
    name: global-secrets
  target:
    creationPolicy: Owner
    deletionPolicy: Retain
    template:
      data:
        password: '{{ .password }}'
        username: gitea_admin
      engineVersion: v2

This will create a corresponding Kubernetes secret:

kubectl describe secrets -n gitea gitea-admin-secret

Name:         gitea-admin-secret
Namespace:    gitea
Labels:       <none>
Annotations:  reconcile.external-secrets.io/data-hash: <REDACTED>

Type:  Opaque

Data
====
password:  32 bytes
username:  11 bytes

Please see the official documentation for more information:

• External Secrets Operator
• API specification