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ExternalSecret

The ExternalSecret describes what data should be fetched, how the data should be transformed and saved as a Kind=Secret:

  • tells the operator what secrets should be synced by using spec.data to explicitly sync individual keys or use spec.dataFrom to get all values from the external API.
  • you can specify how the secret should look like by specifying a spec.target.template

Template

When the controller reconciles the ExternalSecret it will use the spec.template as a blueprint to construct a new Kind=Secret. You can use golang templates to define the blueprint and use template functions to transform secret values. You can also pull in ConfigMaps that contain golang-template data using templateFrom. See advanced templating for details.

Update Behavior

The Kind=Secret is updated when:

  • the spec.refreshInterval has passed and is not 0
  • the ExternalSecret's labels or annotations are changed
  • the ExternalSecret's spec has been changed

You can trigger a secret refresh by using kubectl or any other kubernetes api client:

kubectl annotate es my-es force-sync=$(date +%s) --overwrite

Example

Take a look at an annotated example to understand the design behind the ExternalSecret.

apiVersion: external-secrets.io/v1beta1
kind: ExternalSecret
metadata:
  name: "hello-world"

  # labels and annotations are copied over to the
  # secret that will be created
  labels:
    acme.org/owned-by: "q-team"
  annotations:
    acme.org/sha: 1234

spec:

  # SecretStoreRef defines which SecretStore to use when fetching the secret data
  secretStoreRef:
    name: secret-store-name
    kind: SecretStore  # or ClusterSecretStore

  # RefreshInterval is the amount of time before the values reading again from the SecretStore provider
  # Valid time units are "ns", "us" (or "µs"), "ms", "s", "m", "h" (from time.ParseDuration)
  # May be set to zero to fetch and create it once
  refreshInterval: "1h"

  # the target describes the secret that shall be created
  # there can only be one target per ExternalSecret
  target:

    # The secret name of the resource
    # Defaults to .metadata.name of the ExternalSecret
    # It is immutable
    name: my-secret

    # Enum with values: 'Owner', 'Merge', or 'None'
    # Default value of 'Owner'
    # Owner creates the secret and sets .metadata.ownerReferences of the resource
    # Merge does not create the secret, but merges in the data fields to the secret
    # None does not create a secret (future use with injector)
    creationPolicy: 'Merge'

    # DeletionPolicy defines how/when to delete the Secret in Kubernetes
    # if the provider secret gets deleted.
    # Valid values are Delete, Merge, Retain
    deletionPolicy: "Retain"

    # Specify a blueprint for the resulting Kind=Secret
    template:
      type: kubernetes.io/dockerconfigjson # or TLS...

      metadata:
        annotations: {}
        labels: {}

      # Use inline templates to construct your desired config file that contains your secret
      data:
        config.yml: |
          endpoints:
          - https://{{ .data.user }}:{{ .data.password }}@api.exmaple.com

      # Uses an existing template from configmap
      # Secret is fetched, merged and templated within the referenced configMap data
      # It does not update the configmap, it creates a secret with: data["alertmanager.yml"] = ...result...
      templateFrom:
      - configMap:
          name: alertmanager
          items:
          - key: alertmanager.yaml

  # Data defines the connection between the Kubernetes Secret keys and the Provider data
  data:
    - secretKey: secret-key-to-be-managed
      remoteRef:
        key: provider-key
        version: provider-key-version
        property: provider-key-property
        decodingStrategy: None # can be None, Base64, Base64URL or Auto

  # Used to fetch all properties from the Provider key
  # If multiple dataFrom are specified, secrets are merged in the specified order
  dataFrom:
  - extract:
      key: provider-key
      version: provider-key-version
      property: provider-key-property
      conversionStrategy: Default
      decodingStrategy: Auto
  - find:
      path: path-to-filter
      name:
        regexp: ".*foobar.*"
      tags:
        foo: bar
      conversionStrategy: Unicode
      decodingStrategy: Base64

status:
  # refreshTime is the time and date the external secret was fetched and
  # the target secret updated
  refreshTime: "2019-08-12T12:33:02Z"
  # Standard condition schema
  conditions:
  # ExternalSecret ready condition indicates the secret is ready for use.
  # This is defined as:
  # - The target secret exists
  # - The target secret has been refreshed within the last refreshInterval
  # - The target secret content is up-to-date based on any target templates
  - type: Ready
    status: "True" # False if last refresh was not successful
    reason: "SecretSynced"
    message: "Secret was synced"
    lastTransitionTime: "2019-08-12T12:33:02Z"