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

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

pkg/builder/nodebuilder/node.go

@@ -0,0 +1,122 @@
+/*
+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 nodebuilder
+
+import (
+	apis "github.com/openebs/zfs-localpv/pkg/apis/openebs.io/zfs/v1"
+	"github.com/pkg/errors"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+// Builder is the builder object for ZFSNode
+type Builder struct {
+	node *ZFSNode
+	errs []error
+}
+
+// ZFSNode is a wrapper over
+// ZFSNode API instance
+type ZFSNode struct {
+	// ZFSVolume object
+	Object *apis.ZFSNode
+}
+
+// From returns a new instance of
+// zfs volume
+func From(node *apis.ZFSNode) *ZFSNode {
+	return &ZFSNode{
+		Object: node,
+	}
+}
+
+// NewBuilder returns new instance of Builder
+func NewBuilder() *Builder {
+	return &Builder{
+		node: &ZFSNode{
+			Object: &apis.ZFSNode{},
+		},
+	}
+}
+
+// BuildFrom returns new instance of Builder
+// from the provided api instance
+func BuildFrom(node *apis.ZFSNode) *Builder {
+	if node == nil {
+		b := NewBuilder()
+		b.errs = append(
+			b.errs,
+			errors.New("failed to build zfs node object: nil node"),
+		)
+		return b
+	}
+	return &Builder{
+		node: &ZFSNode{
+			Object: node,
+		},
+	}
+}
+
+// WithNamespace sets the namespace of ZFSNode
+func (b *Builder) WithNamespace(namespace string) *Builder {
+	if namespace == "" {
+		b.errs = append(
+			b.errs,
+			errors.New(
+				"failed to build zfs node object: missing namespace",
+			),
+		)
+		return b
+	}
+	b.node.Object.Namespace = namespace
+	return b
+}
+
+// WithName sets the name of ZFSNode
+func (b *Builder) WithName(name string) *Builder {
+	if name == "" {
+		b.errs = append(
+			b.errs,
+			errors.New(
+				"failed to build zfs node object: missing name",
+			),
+		)
+		return b
+	}
+	b.node.Object.Name = name
+	return b
+}
+
+// WithPools sets the pools of ZFSNode
+func (b *Builder) WithPools(pools []apis.Pool) *Builder {
+	b.node.Object.Pools = pools
+	return b
+}
+
+// WithOwnerReferences sets the owner references of ZFSNode
+func (b *Builder) WithOwnerReferences(ownerRefs ...metav1.OwnerReference) *Builder {
+	b.node.Object.OwnerReferences = ownerRefs
+	return b
+}
+
+// Build returns ZFSNode API object
+func (b *Builder) Build() (*apis.ZFSNode, error) {
+	if len(b.errs) > 0 {
+		return nil, errors.Errorf("%+v", b.errs)
+	}
+
+	return b.node.Object, nil
+}