This library exists to help manage conditions for people that builds Custom Resources Definitions(CRDs) for Kubernetes. Konditionner is built on the same idea as the utility package from API Machinery but with extensibility in mind.
The library is a great addition to your custom resources if your operator uses controller-runtime.
- Reasonable default values for you to use;
- Extensible Status and Types as you see fit;
- Set of utility functions to create, update and delete conditions;
Conditions are ideally used with Status subresources:
# A Custom Resource Spec & Status
type MyRecord struct {
metav1.TypeMeta `json:",inline"`
metav1.ObjectMeta `json:"metadata,omitempty"`
Spec MySpec `json:"spec,omitempty"`
Status MyStatus `json:"status,omitempty"`
}
type MySpec struct {
// ... Fields ...
}
type VolumeFinder konditions.ConditionType = "Volumes"
type SecretMapping konditions.ConditionType = "Secrets"
type MyStatus struct {
Conditions konditions.Conditions `json:"conditions,omitempty"`
}Once the record includes conditions, you can use it to control the handling of your resource within the reconciliation loop.
func (r *MyRecordReconciler) Reconcile(ctx context.Context, req ctrl.Request) (ctrl.Result, error) {
var record MyRecord
if err := r.Get(ctx, req, &record); err != nil {
return ctrl.Result{}, err
}
if record.Conditions().AnyWithStatus(konditions.ConditionError) {
// The record has failed, do not touch the record
return ctrl.Result{}, nil
}
lock := konditions.NewLock(record, r.Client, VolumeFinder)
err := lock.Execute(ctx, func(condition konditions.Condition) error {
// Volume Finder need to be reconciled.
err := r.ReconcileVolume(ctx, record, &condition)
if err != nil {
return err
}
record.Conditions().SetCondition(condition)
return ctrl.Result{}, r.Status().Update(ctx, record)
})
// ...
return ctrl.Result{}, err
}
func (r *MyRecordReconciler) ReconcileVolume(ctx context.Context, record *MyRecord, condition *konditions.Condition) error {
switch condition.Status {
case konditions.ConditionInitialized:
// ... Start working on the Volume Finder condition
if err != nil {
return err
}
condition.Status = konditions.ConditionCreated
condition.Reason = "Volume Found"
return nil
case konditions.ConditionCreated:
// ... Volume was created, let's configure it for our record
}
return nil
}If you'd like to help or you need to make modification to the project to make it better for you, feel free to create issues/pull requests as you see fit. I don't really know the scope of this project yet, so I'll be pretty flexible as to what can be part of Konditionner.