Awesome
Container Storage Interface (CSI) for SeaweedFS
Container storage interface is an industry standard that enables storage vendors to develop a plugin once and have it work across a number of container orchestration systems.
SeaweedFS is a simple and highly scalable distributed file system, to store and serve billions of files fast!
<br>- Deployment
- Update (Safe rollout)
- Testing
- Static and dynamic provisioning
- DataLocality
- License
- Code of conduct
Deployment
Kubernetes (kubectl)
Prerequisites:
- Already have a working Kubernetes cluster (includes
kubectl
) - Already have a working SeaweedFS cluster
Install
Helm
- Add the helm repo;
helm repo add seaweedfs-csi-driver https://seaweedfs.github.io/seaweedfs-csi-driver/helm
- Check versions by
helm repo update seaweedfs-csi-driver
andhelm search repo seaweedfs-csi-driver
Source
- Clone this repository
git clone https://github.com/seaweedfs/seaweedfs-csi-driver.git
-
Adjust your SeaweedFS Filer address via variable SEAWEEDFS_FILER in
deploy/kubernetes/seaweedfs-csi.yaml
(2 places) -
Apply the container storage interface for SeaweedFS for your cluster. Use the '-pre-1.17' version for any cluster pre kubernetes version 1.17.
To generate an up to date manifest from the helm chart, do:
$ helm template seaweedfs ./deploy/helm/seaweedfs-csi-driver > deploy/kubernetes/seaweedfs-csi.yaml
Check the kubelet root directory ,Execute the following command
ps -ef | grep kubelet | grep root-dir
If the result returned from the previous check command is not empty, the root directory (eg:--root-dir=/data/k8s/kubelet/data) representing the kubelet is not the default value (/var/lib/kubelet), so you need to update the kubelet root-dir in the CSI driven deployment file and deploy:
sed 's+/var/lib/kubelet+/data/k8s/kubelet/data+g' deploy/kubernetes/seaweedfs-csi.yaml | kubectl apply -f -
If the result returned by the previous check command is null, you can directly deploy it without modifying the configuration:
$ kubectl apply -f deploy/kubernetes/seaweedfs-csi.yaml
- Ensure all the containers are ready and running
$ kubectl get po -n kube-system
Uninstall
$ kubectl delete -f deploy/kubernetes/sample-busybox-pod.yaml
$ kubectl delete -f deploy/kubernetes/sample-seaweedfs-pvc.yaml
$ kubectl delete -f deploy/kubernetes/seaweedfs-csi.yaml
Kubernetes (helm)
Install
- Clone project
git clone https://github.com/seaweedfs/seaweedfs-csi-driver.git
- Edit
./seaweedfs-csi-driver/deploy/helm/values.yaml
if required and Install
helm install --set seaweedfsFiler=<filerHost:port> seaweedfs-csi-driver ./seaweedfs-csi-driver/deploy/helm/seaweedfs-csi-driver
Uninstall
helm uninstall seaweedfs-csi-driver
Update (Safe rollout)
Updating seaweed-csi-driver DaemonSet (DS) will break processeses who implement fuse mount: newly created pods will not remount net device.
For safe update set node.updateStrategy.type: OnDelete
for manual update. Steps:
- delete DS pods on the node where there is no seaweedfs PV
- cordon or taint node
- evict or delete pods with seaweedfs PV
- delete DS pod on node
- uncordon or remove taint on node
- repeat all steps on [all nodes]
Testing
- Create a persistant volume claim for 5GiB with name
seaweedfs-csi-pvc
with storage classseaweedfs-storage
. The value, 5Gib does not have any significance as for SeaweedFS the whole filesystem is mounted into the container.
$ kubectl apply -f deploy/kubernetes/sample-seaweedfs-pvc.yaml
- Verify if the persistant volume claim exists and wait until its the STATUS is
Bound
$ kubectl get pvc
- After its in
Bound
state, create a sample workload mounting that volume
$ kubectl apply -f deploy/kubernetes/sample-busybox-pod.yaml
- Verify the storage mount of the busybox pod
$ kubectl exec my-csi-app -- df -h
Static and dynamic provisioning
By default, driver will create separate folder (/buckets/<volume-id>
) and will use separate collection (volume-id
)
for each request. Sometimes we need to use exact collection name or change replication options.
It can be done via creating separate storage class with options:
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
name: seaweedfs-special
provisioner: seaweedfs-csi-driver
parameters:
collection: mycollection
replication: "011"
diskType: "ssd"
There is another use case when we need to access one folder from different pods with ro/rw access. In this case we do not need additional StorageClass. We need to create PersistentVolume:
apiVersion: v1
kind: PersistentVolume
metadata:
name: seaweedfs-static
spec:
accessModes:
- ReadWriteMany
capacity:
storage: 1Gi
csi:
driver: seaweedfs-csi-driver
volumeHandle: dfs-test
volumeAttributes:
collection: default
replication: "011"
path: /path/to/files
diskType: "ssd"
readOnly: true
persistentVolumeReclaimPolicy: Retain
volumeMode: Filesystem
and bind PersistentVolumeClaim(s) to it:
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: seaweedfs-static
spec:
storageClassName: ""
volumeName: seaweedfs-static
accessModes:
- ReadWriteMany
resources:
requests:
storage: 1Gi
DataLocality
DataLocality (inspired by Longhorn) allows instructing the storage-driver which volume-locations will be used or preferred in Pods to read & write.
It auto-sets mount-options based on the location a pod is scheduled in and the locality-option wanted. The option can be set and overridden in Driver, StorageClass and PersistentVolume.
Setup
Change the type of locality
Level | Location |
---|---|
Driver | Helm: values.yaml -> dataLocality <br> Or DaemonSet -> Container csi-seaweedfs-plugin -> args --dataLocality= |
StorageClass | parameter.dataLocality |
PersistentVolume | spec.csi.volumeAttributes.dataLocality |
Driver < StorageClass < PersistentVolume
Available options
Option | Effect |
---|---|
none (default) | Changes nothing |
write_preferLocalDc | Sets the DataCenter -mount-option to the current Node-DataCenter, making writes local and allowing reads to occur wherever read data is stored. More Details |
Requirements
Volume-Servers and the CSI-Driver-Node need to have the locality-option DataCenter
correctly set (currently only this option is required).
This can be done manually (although quite tedious) or injected by the Container-Orchestration.
Automatic injection
Kubernetes
Unfortunately Kubernetes doesnt allow grabbing node-labels, which contain well-known region-labels, and setting them as environment-variables. The DownwardAPI is very limited in that regard. (see #40610)
Therefore a workaround must be used. KubeMod can be used based on this comment. This of course requires KubeMod to be installed.
You can activate it in the Helm-Chart values.yaml
-> node.injectTopologyInfoFromNodeLabel.enabled
.
node.injectTopologyInfoFromNodeLabel.labels
decides which labels are grabbed from the node.
It is recommended to use well-known labels to avoid confusion.
License
Code of conduct
Participation in this project is governed by Kubernetes/CNCF code of conduct