Description of problem:
 
While redeploying metrics on existing cluster facing below issue:
 
 The installer fails on the task:

       [1] TASK [openshift_metrics : Applying /tmp/openshift-metrics-ansible-TvYTDY/templates/hawkular-rolebinding.yaml] 

       [2] TASK [openshift_metrics : Checking generation of Service hawkular-cassandra-nodes] 

 The errors is : 
      
       [1] The clusterrolebindings \"hawkular-view\" is invalid: subjects[0].namespace: Required value"  

Workaround  :

Once added this missing variable as following: 
- name: generate view role binding for the hawkular service account
  template:
    src: rolebinding.j2
    dest: "{{ mktemp.stdout }}/templates/hawkular-rolebinding.yaml"
  vars:
    obj_name: hawkular-view
    labels:
      metrics-infra: hawkular
    roleRef:
      name: view
    subjects:
    - kind: ServiceAccount
      name: hawkular
      namespace: "{{openshift_metrics_project}}"         ### Add this line
  changed_when: no

Then re-ran ansible-playbook -i <inventory> /usr/share/ansible/openshift-ansible/playbooks/openshift-metrics/config.yml  then it was successfully set up. 


How reproducible:

Steps to Reproduce:
1.
2.
3.

Actual results:
Please include the entire output from the last TASK line through the end of output if an error is generated

Expected results:
Add below link in task .
- generate view role binding for the hawkular service account 
line:
namespace: "{{openshift_metrics_project}}"

Pull request for 3.10 installer: https://github.com/openshift/openshift-ansible/pull/10921

Tested with 
# rpm -qa | grep openshift-ansible
openshift-ansible-playbooks-3.10.106-1.git.0.217c6b9.el7.noarch
openshift-ansible-roles-3.10.106-1.git.0.217c6b9.el7.noarch
openshift-ansible-3.10.106-1.git.0.217c6b9.el7.noarch
openshift-ansible-test-3.10.106-1.git.0.217c6b9.el7.noarch
openshift-ansible-docs-3.10.106-1.git.0.217c6b9.el7.noarch

There is not error when redeploy metrics

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2019:0328