README
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resource-refresher
resource-refresher makes it easy to handle resources with parent-child relationships.
How to use
Let's consider the process of creating a child resource from a parent resource.
// some process to create child resource
if _, err := controllerutil.CreateOrUpdate(context.TODO(), r.Client, copiedDeploy, func() error {
copiedDeploy.Labels = child.labels
copiedDeploy.Annotations = child.annotations
copiedDeploy.Spec = child.spec
// In order to support Update, set controller reference here
return controllerutil.SetControllerReference(instance, copiedDeploy, r.Scheme)
}); err != nil {
return ctrl.Result{}, errors.WithStack(err)
}
In this case, it is tedious to calculate the difference between the existing resources in Reconciler.
The resource-refresher will fill in the cluster and differences if you pass it the ideal resource state.
ref := refresh.New(r.client, r.scheme)
if err := ref.Refresh(ctx, &parent, &child); err != nil {
return errors.WithStack(err)
}
}
Read more about the architecture using resource-refresher: Go design theory learned from Kubernetes (in Japanese)
Installation
Run go get github.com/wantedly.com/resource-refresher and import like
import (
refresh "github.com/wantedly/resource-refresher"
)
Documentation
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Index ¶
Constants ¶
This section is empty.
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type Builder ¶
Builder is responsible for creating on Application
Builder - collect information - should not contain any logic regarding generating objects
type Lister ¶
type Lister interface {
GenerateLists() []ObjectList
}
Lister is responsible for generating ObjectList for each resource
Lister - generate objects - should not contain any logic accessing API servers
type ObjectList ¶
type Refresher ¶
type Refresher interface {
// Refresh syncs objects
//
// each object will be processed as described below
// - when it doesn't exist, it will be created
// - when the object exists, it will be updated
//
// Also an object that matches all the conditions below will be deleted
// - owned by parent
// - is not present in list
//
// when return value from Identify of two objects are the same they are considered to be a same object
Refresh(ctx context.Context, parent client.Object, list ObjectList) error
}
Refresher reconciles objects by creating, updating, and deleting
Source Files
Directories