pkg/action: add module

examples:

	err = action.New(c).
		WithMatcher(matcher).
		WithAction(actionUpdate).
		Exec(ctx, d...)
	if err != nil {
		return err
	}

	return action.New(c).
		WithAction(action.Delete).
		ExecWithRetry(ctx, action.IfAnyLeft(action.DefaultMatcher), d...)

Signed-off-by: Yauheni Kaliuta <[email protected]>

pkg/action/action.go

@@ -0,0 +1,212 @@
+package action
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"time"
+
+	"github.com/hashicorp/go-multierror"
+
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	"k8s.io/apimachinery/pkg/api/meta"
+	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
+	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/apimachinery/pkg/util/wait"
+)
+
+type ResourceSpec struct {
+	Gvk       schema.GroupVersionKind
+	Namespace string
+	// path to the field, like "metadata", "name"
+	Path []string
+	// set of values for the field to match object, any one matches
+	Values []string
+}
+
+type MatcherFunc func(r ResourceSpec, obj *unstructured.Unstructured) (bool, error)
+type ActionFunc func(ctx context.Context, c client.Client, r ResourceSpec, obj *unstructured.Unstructured) error
+type RetryCheckFunc func(ctx context.Context, c client.Client, resources ...ResourceSpec) (bool, error)
+
+type Action struct {
+	client client.Client
+
+	matcher MatcherFunc
+	actions []ActionFunc
+}
+
+// shouldn't just return false on error?
+func DefaultMatcher(r ResourceSpec, obj *unstructured.Unstructured) (bool, error) {
+	if len(r.Path) == 0 || len(r.Values) == 0 {
+		return true, nil
+	}
+
+	v, ok, err := unstructured.NestedString(obj.Object, r.Path...)
+	if err != nil {
+		return false, fmt.Errorf("failed to get field %v for %s %s/%s: %w", r.Path, r.Gvk.Kind, r.Namespace, obj.GetName(), err)
+	}
+
+	if !ok {
+		return false, fmt.Errorf("unexisting path to handle: %v", r.Path)
+	}
+
+	for _, toDelete := range r.Values {
+		if v == toDelete {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func New(c client.Client) *Action {
+	return &Action{
+		client: c,
+		matcher: DefaultMatcher,
+	}
+}
+
+func (o *Action) Or(m1, m2 MatcherFunc) MatcherFunc {
+	return func(r ResourceSpec, obj *unstructured.Unstructured) (bool, error) {
+		res, err := m1(r, obj)
+		if err != nil {
+			return false, err
+		}
+		if res {
+			return true, err
+		}
+		return m2(r, obj)
+	}
+}
+
+func (o *Action) And(m1, m2 MatcherFunc) MatcherFunc {
+	return func(r ResourceSpec, obj *unstructured.Unstructured) (bool, error) {
+		res, err := m1(r, obj)
+		if err != nil {
+			return false, err
+		}
+		if !res {
+			return false, err
+		}
+		return m2(r, obj)
+	}
+}
+
+func (o *Action) WithMatcher(m MatcherFunc) *Action {
+	o.matcher = m
+	return o
+}
+
+func (o *Action) WithAction(a ActionFunc) *Action {
+	o.actions = append(o.actions, a)
+	return o
+}
+
+func (o *Action) execOneResource(ctx context.Context, r ResourceSpec, objs []*unstructured.Unstructured) error {
+	for _, item := range objs {
+		for _, a := range o.actions {
+			err := a(ctx, o.client, r, item)
+			if err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func ListMatched(ctx context.Context, c client.Client, matcher MatcherFunc, resources ...ResourceSpec) (map[*ResourceSpec][]*unstructured.Unstructured, error) {
+	ret := make(map[*ResourceSpec][]*unstructured.Unstructured)
+
+	for _, r := range resources {
+		r := r
+		var items []*unstructured.Unstructured
+
+		list := &unstructured.UnstructuredList{}
+		list.SetGroupVersionKind(r.Gvk)
+
+		err := c.List(ctx, list, client.InNamespace(r.Namespace))
+		if err != nil {
+			if errors.Is(err, &meta.NoKindMatchError{}) {
+				fmt.Printf("Could not list %v: CRD not found\n", r.Gvk)
+				continue
+			} else {
+				return ret, fmt.Errorf("failed to list %s: %w", r.Gvk.Kind, err)
+			}
+		}
+
+		for _, item := range list.Items {
+			item := item
+
+			matched, err := matcher(r, &item)
+			if err != nil {
+				return ret, err
+			}
+
+			if !matched {
+				continue
+			}
+
+			items = append(items, &item)
+		}
+
+		if len(items) > 0 {
+			ret[&r] = items
+		}
+	}
+
+	return ret, nil
+}
+
+func (o *Action) Exec(ctx context.Context, resources ...ResourceSpec) error {
+	var errors *multierror.Error
+
+	matched, err := ListMatched(ctx, o.client, o.matcher, resources...)
+	if err != nil {
+		return err
+	}
+
+	for r, objs := range matched {
+		err := o.execOneResource(ctx, *r, objs)
+		errors = multierror.Append(errors, err)
+	}
+
+	return errors.ErrorOrNil()
+}
+
+func (o *Action) ExecWithRetry(ctx context.Context, shouldRetry RetryCheckFunc, resources ...ResourceSpec) error {
+	return wait.ExponentialBackoffWithContext(ctx, wait.Backoff{
+		// 5, 10, ,20, 40 then timeout
+		Duration: 5 * time.Second,
+		Factor:   2.0,
+		Jitter:   0.1,
+		Steps:    4,
+		Cap:      1 * time.Minute,
+	}, func(ctx context.Context) (bool, error) {
+		err := o.Exec(ctx, resources...)
+		if err != nil {
+			return false, err
+		}
+		return shouldRetry(ctx, o.client, resources...)
+	})
+}
+
+func (o *Action) DryRun(_ context.Context, _ ...ResourceSpec) error {
+	return nil
+}
+
+func Delete(ctx context.Context, c client.Client, r ResourceSpec, obj *unstructured.Unstructured) error {
+	return c.Delete(ctx, obj)
+}
+
+func IfAnyLeft(matcher MatcherFunc) RetryCheckFunc {
+	return func(ctx context.Context, c client.Client, resources ...ResourceSpec) (bool, error) {
+		matched, err := ListMatched(ctx, c, matcher, resources...)
+		if err != nil {
+			return false, nil
+		}
+
+		return len(matched) == 0, nil
+	}
+}