Bug 1541010

Description of problem:
As rolling_update of containerized cluster from 2.4 to 2.5 is supported, We need 
to add steps in article "Updating Red Hat Ceph Storage deployed as a Container Image" to guide users to upgrade containerized cluster from 2.4 to 2.5 using ceph-ansible.

Steps -

1) Enable the Red Hat Ceph Storage 2 Tools repository:

Command - # subscription-manager repos --enable=rhel-7-server-rhceph-2-tools-rpms

2) Update ceph-ansible

Command - #yum update ceph-ansible

3) Navigate to the /usr/share/ceph-ansible/ directory: 

Command - $ cd /usr/share/ceph-ansible/

4) In the group_vars/all.yml file change the ceph_docker_image_tag parameter to point to the newer Ceph container version, for example: 

ceph_docker_image_tag: 2.5

5)  If the cluster you want to upgrade contains any Ceph Object Gateway nodes, add the radosgw_interface parameter to the group_vars/all.yml file.

radosgw_interface: <interface>

6) Copy rolling_update.yml from the infrastructure-playbooks directory to the current directory.

# cp infrastructure-playbooks/rolling_update.yml .

7)  Run the playbook:
$ ansible-playbook rolling_update.yml -e  jewel_minor_update=true


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QE is not sure about whether to retain steps guiding manual way of upgrading cluster as rolling update was not supported for previous releases.