controller.go

Documentation: github.com/GoogleCloudPlatform/k8s-config-connector/pkg/controller/unmanageddetector

     1  // Copyright 2022 Google LLC
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //      http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package unmanageddetector
    16  
    17  import (
    18  	"context"
    19  	"fmt"
    20  	"strings"
    21  
    22  	"github.com/GoogleCloudPlatform/k8s-config-connector/pkg/controller/lifecyclehandler"
    23  	"github.com/GoogleCloudPlatform/k8s-config-connector/pkg/k8s"
    24  
    25  	"github.com/go-logr/logr"
    26  	v1 "k8s.io/api/apps/v1"
    27  	apiextensions "k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1"
    28  	"k8s.io/apimachinery/pkg/api/errors"
    29  	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
    30  	"k8s.io/apimachinery/pkg/labels"
    31  	"k8s.io/apimachinery/pkg/runtime/schema"
    32  	"sigs.k8s.io/controller-runtime/pkg/builder"
    33  	"sigs.k8s.io/controller-runtime/pkg/client"
    34  	"sigs.k8s.io/controller-runtime/pkg/controller"
    35  	klog "sigs.k8s.io/controller-runtime/pkg/log"
    36  	"sigs.k8s.io/controller-runtime/pkg/manager"
    37  	"sigs.k8s.io/controller-runtime/pkg/reconcile"
    38  )
    39  
    40  var logger = klog.Log
    41  
    42  type Reconciler struct {
    43  	lifecyclehandler.LifecycleHandler
    44  	mgr    manager.Manager
    45  	crd    *apiextensions.CustomResourceDefinition
    46  	gvk    schema.GroupVersionKind
    47  	logger logr.Logger
    48  }
    49  
    50  func Add(mgr manager.Manager, crd *apiextensions.CustomResourceDefinition) error {
    51  	kind := crd.Spec.Names.Kind
    52  	apiVersion := k8s.GetAPIVersionFromCRD(crd)
    53  	controllerName := fmt.Sprintf("%v-unmanaged-detector", strings.ToLower(kind))
    54  	r, err := NewReconciler(mgr, crd)
    55  	if err != nil {
    56  		return err
    57  	}
    58  	obj := &unstructured.Unstructured{
    59  		Object: map[string]interface{}{
    60  			"kind":       kind,
    61  			"apiVersion": apiVersion,
    62  		},
    63  	}
    64  	_, err = builder.
    65  		ControllerManagedBy(mgr).
    66  		Named(controllerName).
    67  		WithOptions(controller.Options{MaxConcurrentReconciles: k8s.ControllerMaxConcurrentReconciles}).
    68  		For(obj, builder.OnlyMetadata, builder.WithPredicates(UnmanagedDetectorPredicate{})).
    69  		Build(r)
    70  	if err != nil {
    71  		return fmt.Errorf("error creating new controller: %v", err)
    72  	}
    73  	logger.Info("Registered unmanaged detector controller", "kind", kind, "apiVersion", apiVersion)
    74  	return nil
    75  }
    76  
    77  func NewReconciler(mgr manager.Manager, crd *apiextensions.CustomResourceDefinition) (*Reconciler, error) {
    78  	controllerName := fmt.Sprintf("%v-unmanaged-detector", strings.ToLower(crd.Spec.Names.Kind))
    79  	return &Reconciler{
    80  		LifecycleHandler: lifecyclehandler.NewLifecycleHandlerWithFieldOwner(
    81  			mgr.GetClient(),
    82  			mgr.GetEventRecorderFor(controllerName),
    83  			k8s.UnmanagedDetectorFieldManager,
    84  		),
    85  		mgr: mgr,
    86  		crd: crd,
    87  		gvk: schema.GroupVersionKind{
    88  			Group:   crd.Spec.Group,
    89  			Version: k8s.GetVersionFromCRD(crd),
    90  			Kind:    crd.Spec.Names.Kind,
    91  		},
    92  		logger: logger.WithName(controllerName),
    93  	}, nil
    94  }
    95  
    96  func (r *Reconciler) Reconcile(ctx context.Context, req reconcile.Request) (res reconcile.Result, err error) {
    97  	r.logger.Info("starting reconcile", "resource", req.NamespacedName)
    98  
    99  	u := &unstructured.Unstructured{}
   100  	u.SetGroupVersionKind(r.gvk)
   101  
   102  	if err := r.Get(ctx, req.NamespacedName, u); err != nil {
   103  		if errors.IsNotFound(err) {
   104  			r.logger.Info("resource not found in API server; finishing reconcile", "resource", req.NamespacedName)
   105  			return reconcile.Result{}, nil
   106  		}
   107  		return reconcile.Result{}, err
   108  	}
   109  
   110  	yes, err := controllerExistsForNamespace(ctx, u.GetNamespace(), r)
   111  	if err != nil {
   112  		return reconcile.Result{}, fmt.Errorf("error determining if controller exists for namespace %v: %v", u.GetNamespace(), err)
   113  	}
   114  	if yes {
   115  		// Don't requeue resource for reconciliation; this controller has
   116  		// achieved its purpose.
   117  		r.logger.Info("controller found for resource's namespace; finishing reconcile", "resource", k8s.GetNamespacedName(u))
   118  		return reconcile.Result{}, nil
   119  	}
   120  
   121  	resource, err := k8s.NewResource(u)
   122  	if err != nil {
   123  		return reconcile.Result{}, fmt.Errorf("could not parse resource %v: %v", k8s.GetNamespacedName(u), err)
   124  	}
   125  
   126  	// Don't requeue resource for reconciliation (unless there's an error
   127  	// during the status update); this controller has achieved its purpose.
   128  	r.logger.Info("controller not found for resource's namespace; finishing reconcile", "resource", k8s.GetNamespacedName(u))
   129  	return reconcile.Result{}, r.HandleUnmanaged(ctx, resource)
   130  }
   131  
   132  func controllerExistsForNamespace(ctx context.Context, namespace string, c client.Client) (yes bool, err error) {
   133  	stsLabelSelectorRaw := fmt.Sprintf("%v=%v,%v=%v",
   134  		k8s.KCCComponentLabel, k8s.ControllerManagerNamePrefix,
   135  		k8s.ScopedNamespaceLabel, namespace,
   136  	)
   137  	stsLabelSelector, err := labels.Parse(stsLabelSelectorRaw)
   138  	if err != nil {
   139  		return false, fmt.Errorf("error parsing '%v' as a label selector: %v", stsLabelSelectorRaw, err)
   140  	}
   141  	stsList := &v1.StatefulSetList{}
   142  	stsOpts := &client.ListOptions{
   143  		Namespace:     k8s.SystemNamespace,
   144  		LabelSelector: stsLabelSelector,
   145  		Limit:         1,
   146  	}
   147  	if err := c.List(ctx, stsList, stsOpts); err != nil {
   148  		return false, fmt.Errorf("error listing controller manager StatefulSets: %w", err)
   149  	}
   150  	return len(stsList.Items) > 0, nil
   151  }
   152
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