Reimplementation of the helm operator to enrich the Helm operator's reconciliation with custom Go code to create a hybrid operator.
The Helm operator type automates Helm chart operations
by mapping the values of a Helm chart exactly to a
CustomResourceDefinition and defining its watched resources in a watches.yaml
configuration file.
For creating a Level II+ operator that reuses an already existing Helm chart, a hybrid between the Go and Helm operator types is necessary.
The hybrid approach allows adding customizations to the Helm operator, such as:
- value mapping based on cluster state, or
- executing code in specific events.
// Operator's main.go
chart, err := loader.Load("path/to/chart")
if err != nil {
panic(err)
}
reconciler := reconciler.New(
reconciler.WithChart(*chart),
reconciler.WithGroupVersionKind(gvk),
)
if err := reconciler.SetupWithManager(mgr); err != nil {
panic(fmt.Sprintf("unable to create reconciler: %s", err))
}Add the WATCH_NAMESPACE to the manager files to restrict the namespace to observe where the operator is installed
name: manager
env:
- name: WATCH_NAMESPACE
valueFrom:
fieldRef:
fieldPath: metadata.namespaceFilter the events to the namespace where the operator is installed
// Operator's main.go
watchNamespace = os.Getenv("WATCH_NAMESPACE")
var cacheOpts cache.Options
if watchNamespace != "" {
setupLog.Info("Watching specific namespace", "namespace", watchNamespace)
cacheOpts = cache.Options{
DefaultNamespaces: map[string]cache.Config{
watchNamespace: {},
},
}
} else {
setupLog.Info("Watching all namespaces")
}
mgr, err := ctrl.NewManager(ctrl.GetConfigOrDie(), ctrl.Options{
...
Cache: cacheOpts,
})
...
chart, err := loader.Load("path/to/chart")
if err != nil {
panic(err)
}
reconciler := reconciler.New(
reconciler.WithChart(*chart),
reconciler.WithGroupVersionKind(gvk),
)
if err := reconciler.SetupWithManager(mgr); err != nil {
panic(fmt.Sprintf("unable to create reconciler: %s", err))
}