feat(scheduling): add zfs pool capacity tracking (#335)

Signed-off-by: shubham <shubham.bajpai@mayadata.io>

pkg/mgmt/zfsnode/builder.go

@@ -0,0 +1,157 @@
+/*
+ Copyright © 2021 The OpenEBS 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 zfsnode
+
+import (
+	"time"
+
+	clientset "github.com/openebs/zfs-localpv/pkg/generated/clientset/internalclientset"
+	openebsScheme "github.com/openebs/zfs-localpv/pkg/generated/clientset/internalclientset/scheme"
+	informers "github.com/openebs/zfs-localpv/pkg/generated/informer/externalversions"
+	listers "github.com/openebs/zfs-localpv/pkg/generated/lister/zfs/v1"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/kubernetes/scheme"
+	typedcorev1 "k8s.io/client-go/kubernetes/typed/core/v1"
+	"k8s.io/client-go/tools/cache"
+	"k8s.io/client-go/tools/record"
+	"k8s.io/client-go/util/workqueue"
+	"k8s.io/klog"
+)
+
+const controllerAgentName = "zfsnode-controller"
+
+// NodeController is the controller implementation for zfs node resources
+type NodeController struct {
+	// kubeclientset is a standard kubernetes clientset
+	kubeclientset kubernetes.Interface
+
+	// clientset is a openebs custom resource package generated for custom API group.
+	clientset clientset.Interface
+
+	NodeLister listers.ZFSNodeLister
+
+	// NodeSynced is used for caches sync to get populated
+	NodeSynced cache.InformerSynced
+
+	// workqueue is a rate limited work queue. This is used to queue work to be
+	// processed instead of performing it as soon as a change happens. This
+	// means we can ensure we only process a fixed amount of resources at a
+	// time, and makes it easy to ensure we are never processing the same item
+	// simultaneously in two different workers.
+	workqueue workqueue.RateLimitingInterface
+
+	// recorder is an event recorder for recording Event resources to the
+	// Kubernetes API.
+	recorder record.EventRecorder
+
+	// pollInterval controls the polling frequency of syncing up the vg metadata.
+	pollInterval time.Duration
+
+	// ownerRef is used to set the owner reference to zfsnode objects.
+	ownerRef metav1.OwnerReference
+}
+
+// NodeControllerBuilder is the builder object for controller.
+type NodeControllerBuilder struct {
+	NodeController *NodeController
+}
+
+// NewNodeControllerBuilder returns an empty instance of controller builder.
+func NewNodeControllerBuilder() *NodeControllerBuilder {
+	return &NodeControllerBuilder{
+		NodeController: &NodeController{},
+	}
+}
+
+// withKubeClient fills kube client to controller object.
+func (cb *NodeControllerBuilder) withKubeClient(ks kubernetes.Interface) *NodeControllerBuilder {
+	cb.NodeController.kubeclientset = ks
+	return cb
+}
+
+// withOpenEBSClient fills openebs client to controller object.
+func (cb *NodeControllerBuilder) withOpenEBSClient(cs clientset.Interface) *NodeControllerBuilder {
+	cb.NodeController.clientset = cs
+	return cb
+}
+
+// withNodeLister fills Node lister to controller object.
+func (cb *NodeControllerBuilder) withNodeLister(sl informers.SharedInformerFactory) *NodeControllerBuilder {
+	NodeInformer := sl.Zfs().V1().ZFSNodes()
+	cb.NodeController.NodeLister = NodeInformer.Lister()
+	return cb
+}
+
+// withNodeSynced adds object sync information in cache to controller object.
+func (cb *NodeControllerBuilder) withNodeSynced(sl informers.SharedInformerFactory) *NodeControllerBuilder {
+	NodeInformer := sl.Zfs().V1().ZFSNodes()
+	cb.NodeController.NodeSynced = NodeInformer.Informer().HasSynced
+	return cb
+}
+
+// withWorkqueue adds workqueue to controller object.
+func (cb *NodeControllerBuilder) withWorkqueueRateLimiting() *NodeControllerBuilder {
+	cb.NodeController.workqueue = workqueue.NewNamedRateLimitingQueue(workqueue.DefaultControllerRateLimiter(), "Node")
+	return cb
+}
+
+// withRecorder adds recorder to controller object.
+func (cb *NodeControllerBuilder) withRecorder(ks kubernetes.Interface) *NodeControllerBuilder {
+	klog.Infof("Creating event broadcaster")
+	eventBroadcaster := record.NewBroadcaster()
+	eventBroadcaster.StartLogging(klog.Infof)
+	eventBroadcaster.StartRecordingToSink(&typedcorev1.EventSinkImpl{Interface: ks.CoreV1().Events("")})
+	recorder := eventBroadcaster.NewRecorder(scheme.Scheme, corev1.EventSource{Component: controllerAgentName})
+	cb.NodeController.recorder = recorder
+	return cb
+}
+
+// withEventHandler adds event handlers controller object.
+func (cb *NodeControllerBuilder) withEventHandler(cvcInformerFactory informers.SharedInformerFactory) *NodeControllerBuilder {
+	cvcInformer := cvcInformerFactory.Zfs().V1().ZFSNodes()
+	// Set up an event handler for when zfs node vg change.
+	// Note: rather than setting up the resync period at informer level,
+	// we are controlling the syncing based on pollInternal. See
+	// NodeController#Run func for more details.
+	cvcInformer.Informer().AddEventHandlerWithResyncPeriod(cache.ResourceEventHandlerFuncs{
+		AddFunc:    cb.NodeController.addNode,
+		UpdateFunc: cb.NodeController.updateNode,
+		DeleteFunc: cb.NodeController.deleteNode,
+	}, 0)
+	return cb
+}
+
+func (cb *NodeControllerBuilder) withPollInterval(interval time.Duration) *NodeControllerBuilder {
+	cb.NodeController.pollInterval = interval
+	return cb
+}
+
+func (cb *NodeControllerBuilder) withOwnerReference(ownerRef metav1.OwnerReference) *NodeControllerBuilder {
+	cb.NodeController.ownerRef = ownerRef
+	return cb
+}
+
+// Build returns a controller instance.
+func (cb *NodeControllerBuilder) Build() (*NodeController, error) {
+	err := openebsScheme.AddToScheme(scheme.Scheme)
+	if err != nil {
+		return nil, err
+	}
+	return cb.NodeController, nil
+}