adding ComponentConfig type and Options parsing

Signed-off-by: Chris Hein <me@chrishein.com>

.golangci.yml

@@ -28,7 +28,6 @@ linters:
   - unparam
   - ineffassign
   - nakedret
-  - interfacer
   - gocyclo
   - lll
   - dupl

Makefile

@@ -39,6 +39,7 @@ TOOLS_DIR := hack/tools
 TOOLS_BIN_DIR := $(TOOLS_DIR)/bin
 GOLANGCI_LINT := $(abspath $(TOOLS_BIN_DIR)/golangci-lint)
 GO_APIDIFF := $(TOOLS_BIN_DIR)/go-apidiff
+CONTROLLER_GEN := $(TOOLS_BIN_DIR)/controller-gen
 
 # The help will print out all targets with their descriptions organized bellow their categories. The categories are represented by `##@` and the target descriptions by `##`.
 # The awk commands is responsible to read the entire set of makefiles included in this invocation, looking for lines of the file as xyz: ## something, and then pretty-format the target and help. Then, if there's a line with ##@ something, that gets pretty-printed as a category.
@@ -66,6 +67,9 @@ $(GOLANGCI_LINT): $(TOOLS_DIR)/go.mod # Build golangci-lint from tools folder.
 $(GO_APIDIFF): $(TOOLS_DIR)/go.mod # Build go-apidiff from tools folder.
 	cd $(TOOLS_DIR) && go build -tags=tools -o bin/go-apidiff github.com/joelanford/go-apidiff
 
+$(CONTROLLER_GEN): $(TOOLS_DIR)/go.mod # Build controller-gen from tools folder.
+	cd $(TOOLS_DIR) && go build -tags=tools -o bin/controller-gen sigs.k8s.io/controller-tools/cmd/controller-gen
+
 ## --------------------------------------
 ## Linting
 ## --------------------------------------
@@ -83,6 +87,10 @@ modules: ## Runs go mod to ensure modules are up to date.
 	go mod tidy
 	cd $(TOOLS_DIR); go mod tidy
 
+.PHONY: generate
+generate: $(CONTROLLER_GEN) ## Runs controller-gen for internal types for config file
+	$(CONTROLLER_GEN) object paths="./pkg/config/v1alpha1/..."
+
 ## --------------------------------------
 ## Cleanup / Verification
 ## --------------------------------------

examples/configfile/builtin/config.yaml

@@ -0,0 +1,6 @@
+apiServer: controller-runtime.sigs.k8s.io/v1alpha1
+kind: GenericControllerConfiguration
+namespace: default
+metricsBindAddress: :9091
+leaderElection:
+  leaderElect: false

examples/configfile/builtin/controller.go

@@ -0,0 +1,74 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"context"
+	"fmt"
+
+	appsv1 "k8s.io/api/apps/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+)
+
+// reconcileReplicaSet reconciles ReplicaSets
+type reconcileReplicaSet struct {
+	// client can be used to retrieve objects from the APIServer.
+	client client.Client
+}
+
+// Implement reconcile.Reconciler so the controller can reconcile objects
+var _ reconcile.Reconciler = &reconcileReplicaSet{}
+
+func (r *reconcileReplicaSet) Reconcile(ctx context.Context, request reconcile.Request) (reconcile.Result, error) {
+	// set up a convenient log object so we don't have to type request over and over again
+	log := log.FromContext(ctx)
+
+	// Fetch the ReplicaSet from the cache
+	rs := &appsv1.ReplicaSet{}
+	err := r.client.Get(context.TODO(), request.NamespacedName, rs)
+	if errors.IsNotFound(err) {
+		log.Error(nil, "Could not find ReplicaSet")
+		return reconcile.Result{}, nil
+	}
+
+	if err != nil {
+		return reconcile.Result{}, fmt.Errorf("could not fetch ReplicaSet: %+v", err)
+	}
+
+	// Print the ReplicaSet
+	log.Info("Reconciling ReplicaSet", "container name", rs.Spec.Template.Spec.Containers[0].Name)
+
+	// Set the label if it is missing
+	if rs.Labels == nil {
+		rs.Labels = map[string]string{}
+	}
+	if rs.Labels["hello"] == "world" {
+		return reconcile.Result{}, nil
+	}
+
+	// Update the ReplicaSet
+	rs.Labels["hello"] = "world"
+	err = r.client.Update(context.TODO(), rs)
+	if err != nil {
+		return reconcile.Result{}, fmt.Errorf("could not write ReplicaSet: %+v", err)
+	}
+
+	return reconcile.Result{}, nil
+}

examples/configfile/builtin/main.go

@@ -0,0 +1,86 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"os"
+
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
+	"sigs.k8s.io/controller-runtime/pkg/client/config"
+	cfg "sigs.k8s.io/controller-runtime/pkg/config"
+	"sigs.k8s.io/controller-runtime/pkg/controller"
+	"sigs.k8s.io/controller-runtime/pkg/handler"
+	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+	"sigs.k8s.io/controller-runtime/pkg/manager"
+	"sigs.k8s.io/controller-runtime/pkg/manager/signals"
+	"sigs.k8s.io/controller-runtime/pkg/source"
+)
+
+var scheme = runtime.NewScheme()
+
+func init() {
+	log.SetLogger(zap.New())
+	clientgoscheme.AddToScheme(scheme)
+}
+
+func main() {
+	entryLog := log.Log.WithName("entrypoint")
+
+	// Setup a Manager
+	entryLog.Info("setting up manager")
+	mgr, err := manager.New(config.GetConfigOrDie(), manager.Options{
+		Scheme: scheme,
+	}.AndFromOrDie(cfg.FromFile()))
+	if err != nil {
+		entryLog.Error(err, "unable to set up overall controller manager")
+		os.Exit(1)
+	}
+
+	// Setup a new controller to reconcile ReplicaSets
+	entryLog.Info("Setting up controller")
+	c, err := controller.New("foo-controller", mgr, controller.Options{
+		Reconciler: &reconcileReplicaSet{client: mgr.GetClient()},
+	})
+	if err != nil {
+		entryLog.Error(err, "unable to set up individual controller")
+		os.Exit(1)
+	}
+
+	// Watch ReplicaSets and enqueue ReplicaSet object key
+	if err := c.Watch(&source.Kind{Type: &appsv1.ReplicaSet{}}, &handler.EnqueueRequestForObject{}); err != nil {
+		entryLog.Error(err, "unable to watch ReplicaSets")
+		os.Exit(1)
+	}
+
+	// Watch Pods and enqueue owning ReplicaSet key
+	if err := c.Watch(&source.Kind{Type: &corev1.Pod{}},
+		&handler.EnqueueRequestForOwner{OwnerType: &appsv1.ReplicaSet{}, IsController: true}); err != nil {
+		entryLog.Error(err, "unable to watch Pods")
+		os.Exit(1)
+	}
+
+	entryLog.Info("starting manager")
+	if err := mgr.Start(signals.SetupSignalHandler()); err != nil {
+		entryLog.Error(err, "unable to run manager")
+		os.Exit(1)
+	}
+}

examples/configfile/custom/config.yaml

@@ -0,0 +1,7 @@
+apiServer: examples.x-k8s.io/v1alpha1
+kind: CustomControllerConfiguration
+clusterName: example-test
+namespace: default
+metricsBindAddress: :8081
+leaderElection:
+  leaderElect: false

examples/configfile/custom/controller.go

@@ -0,0 +1,74 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"context"
+	"fmt"
+
+	appsv1 "k8s.io/api/apps/v1"
+	"k8s.io/apimachinery/pkg/api/errors"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/reconcile"
+)
+
+// reconcileReplicaSet reconciles ReplicaSets
+type reconcileReplicaSet struct {
+	// client can be used to retrieve objects from the APIServer.
+	client client.Client
+}
+
+// Implement reconcile.Reconciler so the controller can reconcile objects
+var _ reconcile.Reconciler = &reconcileReplicaSet{}
+
+func (r *reconcileReplicaSet) Reconcile(ctx context.Context, request reconcile.Request) (reconcile.Result, error) {
+	// set up a convenient log object so we don't have to type request over and over again
+	log := log.FromContext(ctx)
+
+	// Fetch the ReplicaSet from the cache
+	rs := &appsv1.ReplicaSet{}
+	err := r.client.Get(context.TODO(), request.NamespacedName, rs)
+	if errors.IsNotFound(err) {
+		log.Error(nil, "Could not find ReplicaSet")
+		return reconcile.Result{}, nil
+	}
+
+	if err != nil {
+		return reconcile.Result{}, fmt.Errorf("could not fetch ReplicaSet: %+v", err)
+	}
+
+	// Print the ReplicaSet
+	log.Info("Reconciling ReplicaSet", "container name", rs.Spec.Template.Spec.Containers[0].Name)
+
+	// Set the label if it is missing
+	if rs.Labels == nil {
+		rs.Labels = map[string]string{}
+	}
+	if rs.Labels["hello"] == "world" {
+		return reconcile.Result{}, nil
+	}
+
+	// Update the ReplicaSet
+	rs.Labels["hello"] = "world"
+	err = r.client.Update(context.TODO(), rs)
+	if err != nil {
+		return reconcile.Result{}, fmt.Errorf("could not write ReplicaSet: %+v", err)
+	}
+
+	return reconcile.Result{}, nil
+}

examples/configfile/custom/main.go

@@ -0,0 +1,90 @@
+/*
+Copyright 2020 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"os"
+
+	appsv1 "k8s.io/api/apps/v1"
+	corev1 "k8s.io/api/core/v1"
+	"k8s.io/apimachinery/pkg/runtime"
+	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
+	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
+	"sigs.k8s.io/controller-runtime/examples/configfile/custom/v1alpha1"
+	"sigs.k8s.io/controller-runtime/pkg/client/config"
+	cfg "sigs.k8s.io/controller-runtime/pkg/config"
+	"sigs.k8s.io/controller-runtime/pkg/controller"
+	"sigs.k8s.io/controller-runtime/pkg/handler"
+	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+	"sigs.k8s.io/controller-runtime/pkg/manager"
+	"sigs.k8s.io/controller-runtime/pkg/manager/signals"
+	"sigs.k8s.io/controller-runtime/pkg/source"
+)
+
+var scheme = runtime.NewScheme()
+
+func init() {
+	log.SetLogger(zap.New())
+	clientgoscheme.AddToScheme(scheme)
+	v1alpha1.AddToScheme(scheme)
+}
+
+func main() {
+	entryLog := log.Log.WithName("entrypoint")
+
+	// Setup a Manager
+	entryLog.Info("setting up manager")
+	ctrlConfig := v1alpha1.CustomControllerConfiguration{}
+
+	mgr, err := manager.New(config.GetConfigOrDie(), manager.Options{
+		Scheme: scheme,
+	}.AndFromOrDie(cfg.FromFile().OfKind(&ctrlConfig)))
+	if err != nil {
+		entryLog.Error(err, "unable to set up overall controller manager")
+		os.Exit(1)
+	}
+
+	// Setup a new controller to reconcile ReplicaSets
+	entryLog.Info("Setting up controller in cluster", "name", ctrlConfig.ClusterName)
+	c, err := controller.New("foo-controller", mgr, controller.Options{
+		Reconciler: &reconcileReplicaSet{client: mgr.GetClient()},
+	})
+	if err != nil {
+		entryLog.Error(err, "unable to set up individual controller")
+		os.Exit(1)
+	}
+
+	// Watch ReplicaSets and enqueue ReplicaSet object key
+	if err := c.Watch(&source.Kind{Type: &appsv1.ReplicaSet{}}, &handler.EnqueueRequestForObject{}); err != nil {
+		entryLog.Error(err, "unable to watch ReplicaSets")
+		os.Exit(1)
+	}
+
+	// Watch Pods and enqueue owning ReplicaSet key
+	if err := c.Watch(&source.Kind{Type: &corev1.Pod{}},
+		&handler.EnqueueRequestForOwner{OwnerType: &appsv1.ReplicaSet{}, IsController: true}); err != nil {
+		entryLog.Error(err, "unable to watch Pods")
+		os.Exit(1)
+	}
+
+	entryLog.Info("starting manager")
+	if err := mgr.Start(signals.SetupSignalHandler()); err != nil {
+		entryLog.Error(err, "unable to run manager")
+		os.Exit(1)
+	}
+}