Ceph

    PLEASE NOTE: This document applies to v0.7 version and not to the latest stable release v1.9

    Quickstart Guide

    Welcome to Rook! We hope you have a great experience installing the Rook storage platform to enable highly available, durable storage in your cluster. If you have any questions along the way, please don’t hesitate to ask us in our Slack channel.

    This guide will walk you through the basic setup of a Rook cluster. This will enable you to consume block, object, and file storage from other pods running in your cluster.

    Minimum Version

    Kubernetes v1.6 or higher is targeted by Rook (while Rook is in alpha it will track the latest release to use the latest features).

    Support is available for Kubernetes v1.5.2, although your mileage may vary. You will need to use the yaml files from the 1.5 folder.

    Prerequisites

    To make sure you have a Kubernetes cluster that is ready for Rook, you can follow these instructions.

    If you are using dataDirHostPath to persist rook data on kubernetes hosts, make sure your host has at least 5GB of space available on the specified path.

    TL;DR

    If you’re feeling lucky, a simple Rook cluster can be created with the following kubectl commands. For the more detailed install, skip to the next section to deploy the Rook operator.

    cd cluster/examples/kubernetes
    kubectl create -f rook-operator.yaml
    kubectl create -f rook-cluster.yaml
    

    After the cluster is running, you can create block, object, or file storage to be consumed by other applications in your cluster.

    Deploy the Rook Operator

    The first step is to deploy the Rook system components, which include the Rook agent running on each node in your cluster as well as Rook operator pod.

    cd cluster/examples/kubernetes
    kubectl create -f rook-operator.yaml
    
    # verify the rook-operator and rook-agents pods are in the `Running` state before proceeding
    kubectl -n rook-system get pod
    

    You can also deploy the operator with the Rook Helm Chart.


    Restart Kubelet

    (K8S 1.7.x and older only)

    For versions of Kubernetes prior to 1.8, the Kubelet process on all nodes will require a restart after the Rook operator and Rook agents have been deployed. As part of their initial setup, the Rook agents deploy and configure a Flexvolume plugin in order to integrate with Kubernetes’ volume controller framework. In Kubernetes v1.8+, the dynamic Flexvolume plugin discovery will find and initialize our plugin, but in older versions of Kubernetes a manual restart of the Kubelet will be required.

    Disable Attacher-detacher controller

    (K8S 1.6.x only)

    For Kubernetes 1.6, it is also necessary to pass the --enable-controller-attach-detach=false flag to Kubelet when you restart it. This is a workaround for a Kubernetes issue that only affects 1.6.


    Create a Rook Cluster

    Now that the Rook operator and agent pods are running, we can create the Rook cluster. For the cluster to survive reboots, make sure you set the dataDirHostPath property. For more settings, see the documentation on configuring the cluster.

    Save the cluster spec as rook-cluster.yaml:

    apiVersion: v1
    kind: Namespace
    metadata:
      name: rook
    ---
    apiVersion: rook.io/v1alpha1
    kind: Cluster
    metadata:
      name: rook
      namespace: rook
    spec:
      dataDirHostPath: /var/lib/rook
      storage:
        useAllNodes: true
        useAllDevices: false
        storeConfig:
          storeType: bluestore
          databaseSizeMB: 1024
          journalSizeMB: 1024
    

    Create the cluster:

    kubectl create -f rook-cluster.yaml
    

    Use kubectl to list pods in the rook namespace. You should be able to see the following pods once they are all running:

    $ kubectl -n rook get pod
    NAME                              READY     STATUS    RESTARTS   AGE
    rook-api-1511082791-7qs0m         1/1       Running   0          5m
    rook-ceph-mgr0-1279756402-wc4vt   1/1       Running   0          5m
    rook-ceph-mon0-jflt5              1/1       Running   0          6m
    rook-ceph-mon1-wkc8p              1/1       Running   0          6m
    rook-ceph-mon2-p31dj              1/1       Running   0          6m
    rook-ceph-osd-0h6nb               1/1       Running   0          5m
    

    Storage

    For a walkthrough of the three types of storage exposed by Rook, see the guides for:

    • Block: Create block storage to be consumed by a pod
    • Object: Create an object store that is accessible inside or outside the Kubernetes cluster
    • Shared File System: Create a file system to be shared across multiple pods

    Tools

    We have created a toolbox container that contains the full suite of Ceph clients for debugging and troubleshooting your Rook cluster. Please see the toolbox readme for setup and usage information. Also see our advanced configuration document for helpful maintenance and tuning examples.

    The toolbox also contains the rookctl tool as required in the File System and Object walkthroughs, or a simplified walkthrough of block, file and object storage. In the near future, rookctl will not be required for kubernetes scenarios.

    Monitoring

    Each Rook cluster has some built in metrics collectors/exporters for monitoring with Prometheus. To learn how to set up monitoring for your Rook cluster, you can follow the steps in the monitoring guide.

    Teardown

    When you are done with the test cluster, see these instructions to clean up the cluster.