The composition-dynamic-controller is an operator that is instantiated by the core-provider to manage the Custom Resources whose Custom Resource Definition is generated by the core-provider.
The composition-dynamic-controller is an operator designed to manage the lifecycle of a Helm chart based on specifications defined within its Custom Resource (CR) and the actions performed on this CR.
In practice, when a Custom Resource (CR) is created, the instance of composition-dynamic-controller enabled to manage this specific Group Version Kind (GVK), checks if a Helm release associated with the CR already exists in the cluster. If not, it performs an helm install using the values specified in the CR to create a new release. However, if the release does already exist, it instead executes an helm upgrade, updating the release's values with those specified in the CR. Additionally, when the CR is deleted from the cluster, the instance of the composition-dynamic-controller performs an helm uninstall on the release.
The status of the composition is True if the realease has been correctly installed.
Starting from release 0.16.0, the composition-dynamic-controller automatically generates its own RBAC (Role-Based Access Control) policy. Prior to this, RBAC configurations needed to be manually defined. The controller leverages chart-inspector to obtain a list of the resources involved in the chart installation. Based on this information, the composition-dynamic-controller dynamically creates the necessary RBAC policy, ensuring that the appropriate roles and permissions are granted for managing the Helm chart resources.
This automatic RBAC generation simplifies deployment and ensures that the composition-dynamic-controller has the required permissions to perform operations like helm install, helm upgrade, and helm uninstall, depending on the status of the associated Custom Resource (CR). The dynamic creation of RBAC policies eliminates the need for manual intervention, streamlining the operational workflow and ensuring a more seamless experience when managing resources with composition-dynamic-controller.
apiVersion: composition.krateo.io/v12-8-3
kind: Postgresql
metadata:
name: sample
namespace: krateo-system
spec:
architecture: standaloneThe manifest described above represents a Custom Resource (CR) of kind Postgresql, and its apiVersion is composition.krateo.io/v12-8-3. This CRD was generated by the core-provider based on the specifications outlined in the CompositionDefinition. Applying this manifest within the cluster initiates the installation of a chart associated with the corresponding instance of the composition-dynamic-controller.
These enviroment varibles can be changed in the Deployment of the composition-dynamic-controller we need to tweak.
| Name | Description | Default Value |
|---|---|---|
| COMPOSITION_CONTROLLER_DEBUG | dump verbose output | false |
| COMPOSITION_CONTROLLER_WORKERS | number of workers | 1 |
| COMPOSITION_CONTROLLER_RESYNC_INTERVAL | resync interval | 3m |
| COMPOSITION_CONTROLLER_GROUP | resource api group | |
| COMPOSITION_CONTROLLER_VERSION | resource api version | |
| COMPOSITION_CONTROLLER_RESOURCE | resource plural name | |
| COMPOSITION_CONTROLLER_SA_NAME | cdc deployment ServiceAccount name | |
| COMPOSITION_CONTROLLER_SA_NAMESPACE | cdc deployment ServiceAccount namespace | |
| URL_PLURALS | url to krateo pluraliser service | http://bff.krateo-system.svc.cluster.local:8081/api-info/names |
| URL_CHART_INSPECTOR | url to chart inspector | http://chart-inspector.krateo-system.svc.cluster.local:8081/ |
| KRATEO_NAMESPACE | namespace where krateo is installed | krateo-system |
| HELM_REGISTRY_CONFIG_PATH | default helm config path | /tmp |
| HELM_MAX_HISTORY | Max Helm History | 10 |