Allow performing Ceph update/upgrade separately

Running `openstack overcloud external-update run` will update all
external services. This commit adds possibility of running `openstack
overcloud external-update run --tags ceph` to specifically update just
Ceph. It works analogically for upgrades.

Change-Id: Ic1786b6dbfa54516bfb836b450fc35452dca8cb5
Partial-Bug: #1783949

common/deploy-steps.j2

@@ -636,11 +636,16 @@ outputs:
             - hosts: DEPLOY_TARGET_HOST
               name: Gather facts from overcloud
               gather_facts: yes
+              tags:
+                - always
+                - facts
             - hosts: all
               name: Load global variables
               gather_facts: no
               tasks:
                 - include_vars: global_vars.yaml
+              tags:
+                - always
             - hosts: DEPLOY_SOURCE_HOST
               name: External update steps
               gather_facts: no
@@ -754,11 +759,16 @@ outputs:
             - hosts: DEPLOY_TARGET_HOST
               name: Gather facts from overcloud
               gather_facts: yes
+              tags:
+                - always
+                - facts
             - hosts: all
               name: Load global variables
               gather_facts: no
               tasks:
                 - include_vars: global_vars.yaml
+              tags:
+                - always
             - hosts: DEPLOY_SOURCE_HOST
               name: External upgrade
               gather_facts: no

docker/services/ceph-ansible/ceph-base.yaml

@@ -343,6 +343,7 @@ outputs:
       external_deploy_tasks:
         - name: ceph_base_external_deploy_init
           when: step == '1'
+          tags: ceph
           block:
             - name: set blacklisted_hostnames
               set_fact:
@@ -418,6 +419,7 @@ outputs:
                           dest: "{{playbook_dir}}/ceph-ansible/host_vars/{% raw %}{{inventory_hostname}}{% endraw %}.yml"
         - name: ceph_base_external_deploy_task
           when: step == '2'
+          tags: ceph
           block:
             - name: run nodes-uuid
               shell:
@@ -478,9 +480,11 @@ outputs:
               shell: "{{ceph_ansible_command}} {{item}}"
       external_update_tasks:
         - name: set ceph_ansible_playbooks_default
+          tags: ceph
           set_fact:
             ceph_ansible_playbooks_default: ["/usr/share/ceph-ansible/infrastructure-playbooks/rolling_update.yml"]
       external_upgrade_tasks:
         - name: set ceph_ansible_playbooks_default
+          tags: ceph
           set_fact:
             ceph_ansible_playbooks_default: ["/usr/share/ceph-ansible/infrastructure-playbooks/rolling_update.yml"]

docker/services/ceph-ansible/ceph-client.yaml

@@ -65,6 +65,7 @@ outputs:
         - {get_attr: [CephBase, role_data, external_deploy_tasks]}
         - - name: ceph_client_external_deploy_init
             when: step == '1'
+            tags: ceph
             block:
               - name: set ceph-ansible group vars clients
                 set_fact:

docker/services/ceph-ansible/ceph-external.yaml

@@ -71,6 +71,7 @@ outputs:
         - {get_attr: [CephBase, role_data, external_deploy_tasks]}
         - - name: ceph_external_external_deploy_init
             when: step == '1'
+            tags: ceph
             block:
               - name: set ceph-ansible group vars clients
                 set_fact:

docker/services/ceph-ansible/ceph-mds.yaml

@@ -91,6 +91,7 @@ outputs:
         - {get_attr: [CephBase, role_data, external_deploy_tasks]}
         - - name: ceph_mds_external_deploy_init
             when: step == '1'
+            tags: ceph
             block:
               - name: set ceph-ansible group vars mdss
                 set_fact:

docker/services/ceph-ansible/ceph-mgr.yaml

@@ -66,6 +66,7 @@ outputs:
         - {get_attr: [CephBase, role_data, external_deploy_tasks]}
         - - name: ceph_mgr_external_deploy_init
             when: step == '1'
+            tags: ceph
             block:
               - name: set ceph-ansible group vars mgrs
                 set_fact:

docker/services/ceph-ansible/ceph-mon.yaml

@@ -84,6 +84,7 @@ outputs:
         - {get_attr: [CephBase, role_data, external_deploy_tasks]}
         - - name: ceph_mon_external_deploy_init
             when: step == '1'
+            tags: ceph
             block:
               - name: set ceph-ansible group vars mons
                 set_fact:

docker/services/ceph-ansible/ceph-nfs.yaml

@@ -79,6 +79,7 @@ outputs:
         - {get_attr: [CephBase, role_data, external_deploy_tasks]}
         - - name: ceph_nfs_external_deploy_init
             when: step == '1'
+            tags: ceph
             block:
               - name: set ceph-ansible group vars nfss
                 set_fact:

docker/services/ceph-ansible/ceph-osd.yaml

@@ -80,6 +80,7 @@ outputs:
         - {get_attr: [CephBase, role_data, external_deploy_tasks]}
         - - name: ceph_osd_external_deploy_init
             when: step == '1'
+            tags: ceph
             block:
               - name: set ceph-ansible group vars osds
                 set_fact:

docker/services/ceph-ansible/ceph-rbdmirror.yaml

@@ -93,6 +93,7 @@ outputs:
         - {get_attr: [CephBase, role_data, external_deploy_tasks]}
         - - name: ceph_rbdmirror_external_deploy_init
             when: step == '1'
+            tags: ceph
             block:
               - name: set ceph-ansible group vars rbdmirrors
                 set_fact:

docker/services/ceph-ansible/ceph-rgw.yaml

@@ -77,6 +77,7 @@ outputs:
         - {get_attr: [CephBase, role_data, external_deploy_tasks]}
         - - name: ceph_rgw_external_deploy_init
             when: step == '1'
+            tags: ceph
             block:
               - name: set ceph-ansible group vars rgws
                 set_fact: