Overview

In OpenShift Enterprise, you can back up (saving state to separate storage) and restore (recreating state from separate storage) at the cluster level. There is also some preliminary support for per-project backup. The full state of a cluster installation includes:

  • etcd data on each master

  • API objects

  • registry storage

  • volume storage

This topic does not cover how to back up and restore persistent storage, as those topics are left to the underlying storage provider.

Prerequisites

  1. Because the restore procedure involves a complete reinstallation, save all the files used in the initial installation. This may include:

  2. Install packages that provide various utility commands:

    # yum install etcd

Note the location of the etcd data directory (or $ETCD_DATA_DIR in the following sections), which depends on how etcd is deployed.

Deployment Type Data Directory

all-in-one cluster

/var/lib/openshift/openshift.local.etcd

external etcd (not on master)

/var/lib/etcd

embedded etcd (on master)

/var/lib/origin/etcd

Cluster Backup

  1. Save all the certificates and keys, on each master:

    # cd /etc/origin/master
    # tar cf /tmp/certs-and-keys-$(hostname).tar \
        master.proxy-client.crt \
        master.proxy-client.key \
        proxyca.crt \
        proxyca.key \
        master.server.crt \
        master.server.key \
        ca.crt \
        ca.key \
        master.etcd-client.crt \
        master.etcd-client.key \
        master.etcd-ca.crt
  2. If etcd is running on more than one host, stop it on each host:

    # sudo systemctl stop etcd

    Although this step is not strictly necessary, doing so ensures that the etcd data is fully synchronized.

  3. Create an etcd backup:

    # etcdctl backup \
        --data-dir $ETCD_DATA_DIR \
        --backup-dir $ETCD_DATA_DIR.bak

    If etcd is running on more than one host, the various instances regularly synchronize their data, so creating a backup for one of them is sufficient.

  4. Create a template for all cluster API objects:

    $ oc export all \
        --exact \(1)
        --all-namespaces \
        --as-template=mycluster \(2)
        > mycluster.template.yaml
    1 Preserve fields that may be cluster specific, such as service portalIP values or generated names.
    2 The output file has kind: Template and metadata.name: mycluster.

    The object types included in oc export all are:

    • BuildConfig

    • Build

    • DeploymentConfig

    • ImageStream

    • Pod

    • ReplicationController

    • Route

    • Service

Cluster Restore

  1. Reinstall OpenShift Enterprise.

    This should be done in the same way that OpenShift Enterprise was previously installed.

  2. Restore the certificates and keys, on each master:

    # cd /etc/origin/master
    # tar xvf /tmp/certs-and-keys-$(hostname).tar
  3. Restore from the etcd backup:

    # mv $ETCD_DATA_DIR $ETCD_DATA_DIR.orig
    # cp -Rp $ETCD_DATA_DIR.bak $ETCD_DATA_DIR
    # chcon -R --reference $ETCD_DATA_DIR.orig $ETCD_DATA_DIR
    # chown -R etcd:etcd $ETCD_DATA_DIR
  4. Create the API objects for the cluster:

    $ oc create -f mycluster.template.yaml

Project Backup

A future release of OpenShift Enterprise will feature specific support for per-project back up and restore.

For now, to back up API objects at the project level, use oc export for each object to be saved. For example, to save the deployment configuration frontend in YAML format:

$ oc export dc frontend -o yaml > dc-frontend.yaml

To back up all of the project (with the exception of cluster objects like namespaces and projects):

$ oc export all -o yaml > project.yaml