Longhorn Manager

Manager for Longhorn.

Requirement

1. Existing Kubernetes Cluster 1.8+
2. Make sure iscsiadm/open-iscsi has been installed on the host.
3. Make sure jq, findmnt, curl has been installed on the host, for the Longhorn Flexvolume Driver.

Build

make

Deployment

kubectl create -Rf deploy/install

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

1. Longhorn Manager
2. Longhorn Flexvolume Driver for Kubernetes
3. Longhorn UI

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. Create the uninstallation job to cleanly purge CRDs from the system and wait for success:

kubectl create -f deploy/uninstall/uninstall.yaml
kubectl get job/longhorn-uninstall -w

Example output:

$ kubectl create -f https://raw.githubusercontent.com/rancher/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 get job/longhorn-uninstall -w
NAME                 COMPLETIONS   DURATION   AGE
longhorn-uninstall   0/1           3s         3s
longhorn-uninstall   1/1           20s        20s
^C

2. Remove remaining components:

kubectl delete -Rf deploy/install
kubectl delete -f deploy/uninstall/uninstall.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.

Integration test

See longhorn-tests repo

Notes:

Google Kubernetes Engine

You will need to create cluster-admin role binding for yourselves before creating the deployment, see here for details.

kubectl create clusterrolebinding cluster-admin-binding --clusterrole=cluster-admin --user=<name@example.com>

Flexvolume Plugin Directory

By default we're using the default Flexvolume Plugin directory, which is /usr/libexec/kubernetes/kubelet-plugins/volume/exec/.

For GKE 1.8+, it should be at: /home/kubernetes/flexvolume.

You may need to change deploy/deploy.yaml volume flexvolume-longhorn-mount location according to your own environment.

Contribution

Please check the Longhorn repo for the contributing guide.

License

Copyright (c) 2014-2019 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.