See also: Controller, Juju | Manage controllers, Terraform Provider for Juju | Manage controllers

As for all Kubernetes clouds, bootstrapping a controller creates the following resources in the cluster.

When bootstrapping a controller on a Kubernetes cloud, Juju creates a namespace for the controller and deploys the controller as a StatefulSet with associated resources. The controller manages the Juju state database (MongoDB) and API server within Kubernetes pods.

Resources created at bootstrap:

  • Namespace: A dedicated namespace for the controller (named controller-<controller-name>).

  • Service: A Kubernetes Service to expose the controller API (type depends on the cloud: LoadBalancer for public clouds, ClusterIP for localhost clouds).

  • ServiceAccount: A service account for the controller with cluster-admin privileges.

  • ClusterRoleBinding: Binds the controller service account to the cluster-admin ClusterRole.

  • StatefulSet: A StatefulSet with the controller pod containing two containers: mongodb (Juju’s state database) and api-server (Juju API server).

  • Secrets: Multiple secrets for TLS certificates (server.pem), shared secrets, and optionally docker registry credentials for private image registries.

  • ConfigMaps: Configuration maps for bootstrap parameters and agent configuration.

  • PersistentVolume and PersistentVolumeClaim: Storage for the controller’s operator-storage (MongoDB data and API server state).

  • Proxy resources (if using ClusterIP Service): Additional ConfigMap, Role, RoleBinding, and ServiceAccount for cluster IP proxy access.