feat(zfspv): adding backup and restore support (#162)

This commit adds support for Backup and Restore controller, which will be watching for
the events. The velero plugin will create a Backup CR to create a backup
with the remote location information, the controller will send the data
to that remote location.

In the same way, the velero plugin will create a Restore CR to restore the
volume from the the remote location and the restore controller will restore
the data.

Steps to use velero plugin for ZFS-LocalPV are :

1. install velero

2. add openebs plugin

velero plugin add openebs/velero-plugin:latest

3. Create the volumesnapshot location :

for full backup :-

```yaml
apiVersion: velero.io/v1
kind: VolumeSnapshotLocation
metadata:
  name: default
  namespace: velero
spec:
  provider: openebs.io/zfspv-blockstore
  config:
    bucket: velero
    prefix: zfs
    namespace: openebs
    provider: aws
    region: minio
    s3ForcePathStyle: "true"
    s3Url: http://minio.velero.svc:9000
```

for incremental backup :-

```yaml
apiVersion: velero.io/v1
kind: VolumeSnapshotLocation
metadata:
  name: default
  namespace: velero
spec:
  provider: openebs.io/zfspv-blockstore
  config:
    bucket: velero
    prefix: zfs
    backup: incremental
    namespace: openebs
    provider: aws
    region: minio
    s3ForcePathStyle: "true"
    s3Url: http://minio.velero.svc:9000
```

4. Create backup

velero backup create my-backup --snapshot-volumes --include-namespaces=velero-ns --volume-snapshot-locations=aws-cloud-default --storage-location=default

5. Create Schedule

velero create schedule newschedule  --schedule="*/1 * * * *" --snapshot-volumes --include-namespaces=velero-ns --volume-snapshot-locations=aws-local-default --storage-location=default

6. Restore from backup

velero restore create --from-backup my-backup --restore-volumes=true --namespace-mappings velero-ns:ns1



Signed-off-by: Pawan <pawan@mayadata.io>

pkg/builder/restorebuilder/build.go

@@ -0,0 +1,169 @@
+/*
+Copyright 2020 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 restorebuilder
+
+import (
+	apis "github.com/openebs/zfs-localpv/pkg/apis/openebs.io/zfs/v1"
+	"github.com/openebs/zfs-localpv/pkg/common/errors"
+)
+
+// Builder is the builder object for ZFSRestore
+type Builder struct {
+	rstr *ZFSRestore
+	errs []error
+}
+
+// NewBuilder returns new instance of Builder
+func NewBuilder() *Builder {
+	return &Builder{
+		rstr: &ZFSRestore{
+			Object: &apis.ZFSRestore{},
+		},
+	}
+}
+
+// BuildFrom returns new instance of Builder
+// from the provided api instance
+func BuildFrom(rstr *apis.ZFSRestore) *Builder {
+	if rstr == nil {
+		b := NewBuilder()
+		b.errs = append(
+			b.errs,
+			errors.New("failed to build rstr object: nil rstr"),
+		)
+		return b
+	}
+	return &Builder{
+		rstr: &ZFSRestore{
+			Object: rstr,
+		},
+	}
+}
+
+// WithNamespace sets the namespace of  ZFSRestore
+func (b *Builder) WithNamespace(namespace string) *Builder {
+	if namespace == "" {
+		b.errs = append(
+			b.errs,
+			errors.New(
+				"failed to build csi rstr object: missing namespace",
+			),
+		)
+		return b
+	}
+	b.rstr.Object.Namespace = namespace
+	return b
+}
+
+// WithName sets the name of ZFSRestore
+func (b *Builder) WithName(name string) *Builder {
+	if name == "" {
+		b.errs = append(
+			b.errs,
+			errors.New(
+				"failed to build csi rstr object: missing name",
+			),
+		)
+		return b
+	}
+	b.rstr.Object.Name = name
+	return b
+}
+
+// WithVolume sets the name of ZFSRestore
+func (b *Builder) WithVolume(name string) *Builder {
+	if name == "" {
+		b.errs = append(
+			b.errs,
+			errors.New(
+				"failed to build csi rstr object: missing volume name",
+			),
+		)
+		return b
+	}
+	b.rstr.Object.Spec.VolumeName = name
+	return b
+}
+
+// WithNode sets the node id for ZFSRestore
+func (b *Builder) WithNode(node string) *Builder {
+	if node == "" {
+		b.errs = append(
+			b.errs,
+			errors.New(
+				"failed to build csi rstr object: missing node name",
+			),
+		)
+		return b
+	}
+	b.rstr.Object.Spec.OwnerNodeID = node
+	return b
+}
+
+// WithStatus sets the status for ZFSRestore
+func (b *Builder) WithStatus(status apis.ZFSRestoreStatus) *Builder {
+	b.rstr.Object.Status = status
+	return b
+}
+
+// WithRemote sets the node id for ZFSRestore
+func (b *Builder) WithRemote(server string) *Builder {
+	if server == "" {
+		b.errs = append(
+			b.errs,
+			errors.New(
+				"failed to build csi rstr object: missing node name",
+			),
+		)
+		return b
+	}
+	b.rstr.Object.Spec.RestoreSrc = server
+	return b
+}
+
+// WithLabels merges existing labels if any
+// with the ones that are provided here
+func (b *Builder) WithLabels(labels map[string]string) *Builder {
+	if len(labels) == 0 {
+		return b
+	}
+
+	if b.rstr.Object.Labels == nil {
+		b.rstr.Object.Labels = map[string]string{}
+	}
+
+	for key, value := range labels {
+		b.rstr.Object.Labels[key] = value
+	}
+	return b
+}
+
+// WithFinalizer merge existing finalizers if any
+// with the ones that are provided here
+func (b *Builder) WithFinalizer(finalizer []string) *Builder {
+	b.rstr.Object.Finalizers = append(b.rstr.Object.Finalizers, finalizer...)
+	return b
+}
+
+// Build returns ZFSRestore API object
+func (b *Builder) Build() (*apis.ZFSRestore, error) {
+	if len(b.errs) > 0 {
+		return nil, errors.Errorf("%+v", b.errs)
+	}
+
+	return b.rstr.Object, nil
+}