This is a Container Storage Interface (CSI) for S3 (or S3 compatible) storage. This can dynamically allocate buckets and mount them via a fuse mount into any container.
This is still very experimental and should not be used in any production environment. Unexpected data loss could occur depending on what mounter and S3 storage backend is being used.
apiVersion: v1 kind: Secret metadata: namespace: kube-system name: csi-s3-secret # Namespace depends on the configuration in the storageclass.yaml namespace: kube-system stringData: accessKeyID: <YOUR_ACCESS_KEY_ID> secretAccessKey: <YOUR_SECRET_ACCES_KEY> # For AWS set it to "https://s3.<region>.amazonaws.com" endpoint: <S3_ENDPOINT_URL> # If not on S3, set it to "" region: <S3_REGION>
The region can be empty if you are using some other S3 compatible storage.
cd deploy/kubernetes kubectl create -f provisioner.yaml kubectl create -f attacher.yaml kubectl create -f csi-s3.yaml
kubectl create -f examples/storageclass.yaml
Create a pvc using the new storage class:
kubectl create -f examples/pvc.yaml
Check if the PVC has been bound:
$ kubectl get pvc csi-s3-pvc NAME STATUS VOLUME CAPACITY ACCESS MODES STORAGECLASS AGE csi-s3-pvc Bound pvc-c5d4634f-8507-11e8-9f33-0e243832354b 5Gi RWO csi-s3 9s
Create a test pod which mounts your volume:
kubectl create -f examples/pod.yaml
If the pod can start, everything should be working.
Test the mount
$ kubectl exec -ti csi-s3-test-nginx bash $ mount | grep fuse s3fs on /var/lib/www/html type fuse.s3fs (rw,nosuid,nodev,relatime,user_id=0,group_id=0,allow_other) $ touch /var/lib/www/html/hello_world
If something does not work as expected, check the troubleshooting section below.
By default, csi-s3 will create a new bucket per volume. The bucket name will match that of the volume ID. If you want your volumes to live in a precreated bucket, you can simply specify the bucket in the storage class parameters:
kind: StorageClass apiVersion: storage.k8s.io/v1 metadata: name: csi-s3-existing-bucket provisioner: ch.ctrox.csi.s3-driver parameters: mounter: rclone bucket: some-existing-bucket-name
If the bucket is specified, it will still be created if it does not exist on the backend. Every volume will get its own prefix within the bucket which matches the volume ID. When deleting a volume, also just the prefix will be deleted.
If you have an existing bucket and with or without a prefix (subpath), you can specify to use a prefixed configuration by setting the parameters as:
kind: StorageClass apiVersion: storage.k8s.io/v1 metadata: name: csi-s3-existing-bucket provisioner: ch.ctrox.csi.s3-driver reclaimPolicy: Retain parameters: mounter: rclone bucket: some-existing-bucket-name # 'usePrefix' must be true in order to enable the prefix feature and to avoid the removal of the prefix or bucket usePrefix: "true" # 'prefix' can be empty (it will mount on the root of the bucket), an existing prefix or a new one. prefix: custom-prefix
Note: all volumes created with this
StorageClass will always be mounted to the same bucket and path, meaning they will be identical.
As S3 is not a real file system there are some limitations to consider here. Depending on what mounter you are using, you will have different levels of POSIX compability. Also depending on what S3 storage backend you are using there are not always consistency guarantees.
The driver can be configured to use one of these mounters to mount buckets:
The mounter can be set as a parameter in the storage class. You can also create multiple storage classes for each mounter if you like.
All mounters have different strengths and weaknesses depending on your use case. Here are some characteristics which should help you choose a mounter:
*s3backer is experimental at this point because volume corruption can occur pretty quickly in case of an unexpected shutdown of a Kubernetes node or CSI pod.
The s3backer binary is not bundled with the normal docker image to keep that as small as possible. Use the
<version>-full image tag for testing s3backer.
Fore more detailed limitations consult the documentation of the different projects.
Check the logs of the provisioner:
kubectl logs -l app=csi-provisioner-s3 -c csi-s3
MountPropagationis not set to
kubectl logs -l app=csi-s3 -c csi-s3
This project can be built like any other go application.
go get -u github.com/ctrox/csi-s3
Currently the driver is tested by the CSI Sanity Tester. As end-to-end tests require S3 storage and a mounter like s3fs, this is best done in a docker container. A Dockerfile and the test script are in the
test directory. The easiest way to run the tests is to just use the make command: