Longhorn Manager

Manager for Longhorn.

Requirements

• Kubernetes cluster:
  • Kubernetes v1.21 or later is installed.
  • Mount propagation is enabled.
• Host:
  • iscsiadm/open-iscsi and nfs-common/nfs-utils/nfs-client are installed.
  • The filesystem (ext4 or XFS) supports the file extents feature for data storage.

Run the environment_check.sh script to check if your system meets the listed requirements. For more information, see the Longhorn documentation.

Build

make

Deployment

• kubectl create -f https://raw.githubusercontent.com/longhorn/longhorn/master/deploy/longhorn.yaml

It will deploy the following components in the longhorn-system namespace:

• Longhorn Manager
• Longhorn Instance Manager
• Longhorn CSI plugin components
• Longhorn UI

For more information, see the Longhorn documentation.

Cleanup

Longhorn CRD has finalizers in them, so user should delete the volumes and related resource first, give manager a chance to clean up after them.

To prevent damage to the Kubernetes cluster, we recommend deleting all Kubernetes workloads using Longhorn volumes (PersistentVolume, PersistentVolumeClaim, StorageClass, Deployment, StatefulSet, DaemonSet, etc).

1. Ensure that the value of the Longhorn setting deleting-confirmation-flag is true.

kubectl -n longhorn-system edit setting deleting-confirmation-flag

2. Create the uninstallation job to cleanly purge CRDs from the system. Verify that uninstallation was successful.

kubectl create -f https://raw.githubusercontent.com/longhorn/longhorn/master/uninstall/uninstall.yaml
kubectl get job/longhorn-uninstall -w

Example output:

$ kubectl create -f https://raw.githubusercontent.com/longhorn/longhorn/master/uninstall/uninstall.yaml
serviceaccount/longhorn-uninstall-service-account created
clusterrole.rbac.authorization.k8s.io/longhorn-uninstall-role created
clusterrolebinding.rbac.authorization.k8s.io/longhorn-uninstall-bind created
job.batch/longhorn-uninstall created

$ kubectl -n longhorn-system get job/longhorn-uninstall -w
NAME                 COMPLETIONS   DURATION   AGE
longhorn-uninstall   0/1           3s         3s
longhorn-uninstall   1/1           20s        20s
^C

3. Remove remaining components.

kubectl delete -f https://raw.githubusercontent.com/longhorn/longhorn/master/uninstall/uninstall.yaml
kubectl delete -f https://raw.githubusercontent.com/longhorn/longhorn/master/deploy/longhorn.yaml

Tip: If you try kubectl delete -Rf deploy/install first and get stuck there, pressing Ctrl C then running kubectl create -f deploy/uninstall/uninstall.yaml can also help you remove Longhorn. Finally, don't forget to cleanup remaining components by running kubectl delete -f deploy/uninstall/uninstall.yaml.

Unit Test

To execute all unit tests, make sure there are no uncommitted changes and run:

make test

If there are uncommitted changes, only the affected modules will be tested. To execute specific unit tests or all tests matching a regex, run:

TESTS=="NodeControllerSuite.*" make test

Integration test

See longhorn-tests repo

Contribution

Please check the Longhorn repo for the contributing guide.

License

Copyright (c) 2014-2024 The Longhorn 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.