OpenEBS-Jiva快速入門

Prerequisites

參考：

• https://docs.openebs.io/docs/next/jivaguide.html
• https://github.com/openebs/jiva-operator/blob/master/docs/quickstart.md
• https://github.com/openebs/jiva-operator

1. Kubernetes version 1.17 or higher.

2. iSCSI initiator utils installed on all the worker nodes(If you are using rancher based cluster perform steps mentioned here).

OPERATING SYSTEM	iSCSI PACKAGE	Commands to install iSCSI	Verify iSCSI Status
RHEL/CentOS	iscsi-initiator-utils	sudo yum install iscsi-initiator-utils -y sudo systemctl enable --now iscsid modprobe iscsi_tcp echo iscsi_tcp >/etc/modules-load.d/iscsi-tcp.conf	sudo systemctl status iscsid.service
Ununtu/ Debian	open-iscsi	sudo apt install open-iscsi sudo systemctl enable --now iscsid modprobe iscsi_tcp echo iscsi_tcp >/etc/modules-load.d/iscsi-tcp.conf	sudo systemctl status iscsid.service
RancherOS	open-iscsi	sudo ros s enable open-iscsi sudo ros s up open-iscsi	ros service list iscsi

1. Access to install RBAC components into kube-system namespace.

2. OpenEBS localpv-hostpath version 2.6.0 or higher.

   kubectl apply -f  https://openebs.github.io/charts/hostpath-operator.yaml
   

   Sample hostpath storage class

   #Sample storage classes for OpenEBS Local PV
   apiVersion: storage.k8s.io/v1
   kind: StorageClass
   metadata:
     name: openebs-hostpath
     annotations:
       openebs.io/cas-type: local
       cas.openebs.io/config: |
         # hostpath type will create a PV by 
         # creating a sub-directory under the
         # BASEPATH provided below.
         - name: StorageType
           value: "hostpath"
         # Specify the location (directory) where
         # where PV(volume) data will be saved. 
         # A sub-directory with pv-name will be 
         # created. When the volume is deleted, 
         # the PV sub-directory will be deleted.
         #Default value is /var/openebs/local
         - name: BasePath
           value: "/var/openebs/local/"
   provisioner: openebs.io/local
   volumeBindingMode: WaitForFirstConsumer
   reclaimPolicy: Delete

 

Install

 

Using Helm Charts:

Install Jiva components using jiva helm charts.

 

Using Operator:

Install the latest release using Jiva Operator yamls.

kubectl apply -f https://openebs.github.io/charts/jiva-operator.yaml

Once installed using any of the above methods, verify that Jiva Operator and jiva csi pods are running.

$ kubectl get pod -n openebs

NAME                                           READY   STATUS    RESTARTS   AGE
jiva-operator-7765cbfffd-vt787                 1/1     Running   0          10s                                                             
openebs-localpv-provisioner-57b44f4664-klsrw   1/1     Running   0          118s                                                            
openebs-jiva-csi-controller-0                  4/4     Running   0          6m14s                                                           
openebs-jiva-csi-node-56t5g                    2/2     Running   0          6m13s                                                           
openebs-jiva-csi-node-xtyhu                    2/2     Running   0          6m20s                                                           
openebs-jiva-csi-node-h2unk                    2/2     Running   0          6m20s

 

Steps to provision a Jiva Volume

1. Create Jiva volume policy to set various policies for creating a jiva volume. A sample jiva volume policy CR looks like:

   apiVersion: openebs.io/v1alpha1
    kind: JivaVolumePolicy
    metadata:
      name: example-jivavolumepolicy
      namespace: openebs
    spec:
      replicaSC: openebs-hostpath
      enableBufio: false
      autoScaling: false
      target:
        replicationFactor: 1
        # monitor: false
        # auxResources:
        # tolerations:
        # resources:
        # affinity:
        # nodeSelector:
        # priorityClassName:
      # replica:
        # tolerations:
        # resources:
        # affinity:
        # nodeSelector:
        # priorityClassName:

   By default, volume data is stored at /var/openebs/<pvc-*> at the worker nodes, to change this behavior, a new replicaSC needs to be created. This tutorial can be referred to create replicaSC and make use of various policies.

2. Create a Storage Class to dynamically provision volumes by specifying above policy:

   apiVersion: storage.k8s.io/v1
   kind: StorageClass
   metadata:
     name: openebs-jiva-csi-sc
   provisioner: jiva.csi.openebs.io
   allowVolumeExpansion: true
   parameters:
     cas-type: "jiva"
     policy: "example-jivavolumepolicy"

3. Create PVC by specifying the above Storage Class in the PVC spec

   kind: PersistentVolumeClaim
   apiVersion: v1
   metadata:
     name: example-jiva-csi-pvc
   spec:
     storageClassName: openebs-jiva-csi-sc
     accessModes:
       - ReadWriteOnce
     resources:
       requests:
         storage: 4Gi

   $ kubectl get pvc
   NAME                   STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS           AGE
   example-jiva-csi-pvc   Bound    pvc-ffc1e885-0122-4b5b-9d36-ae131717a77b   4Gi        RWO            openebs-jiva-csi-sc    1m
   

   Verify volume is ready to serve IOs.

   $ kubectl get jivavolume pvc-ffc1e885-0122-4b5b-9d36-ae131717a77b -n openebs
   NAME                                       REPLICACOUNT   PHASE   STATUS
   pvc-ffc1e885-0122-4b5b-9d36-ae131717a77b   1              Ready   RW
   

4. Deploy an application using the above PVC:

   apiVersion: apps/v1
   kind: Deployment
   metadata:
     name: fio
   spec:
     selector:
       matchLabels:
         name: fio
     replicas: 1
     strategy:
       type: Recreate
       rollingUpdate: null
     template:
       metadata:
         labels:
           name: fio
       spec:
         containers:
         - name: perfrunner
           image: openebs/tests-fio
           command: ["/bin/bash"]
           args: ["-c", "while true ;do sleep 50; done"]
           volumeMounts:
           - mountPath: /datadir
             name: fio-vol
         volumes:
         - name: fio-vol
           persistentVolumeClaim:
             claimName: example-jiva-csi-pvc

   $ kubectl get po
   NAME                   READY   STATUS    RESTARTS   AGE
   fio-68c4c5b545-vg2rc   1/1     Running   0          2m