common: serialise host restart

This commits allows us to restart Ceph daemon machine by machine instead
of restarting all the daemons in a single shot.

Rework the structure of the handler for clarity as well.

Signed-off-by: Sébastien Han <seb@redhat.com>

group_vars/all.yml.sample

@@ -339,6 +339,20 @@ dummy:
 # if you don't want it keep the option commented
 #common_single_host_mode: true
 
+## Handlers - restarting daemons after a config change
+# if for whatever reasons the content of your ceph configuration changes
+# ceph daemons will be restarted as well. At the moment, we can not detect
+# which config option changed so all the daemons will be restarted. Although
+# this restart will be serialized for each node, in between a health check
+# will be performed so we make sure we don't move to the next node until
+# ceph is not healthy
+# Obviously between the checks (for monitors to be in quorum and for osd's pgs
+# to be clean) we have to wait. These retries and delays can be configurable
+# for both monitors and osds.
+#handler_health_mon_check_retries: 5
+#handler_health_mon_check_delay: 10
+#handler_health_osd_check_retries: 40
+#handler_health_osd_check_delay: 30
 
 ###################
 # CONFIG OVERRIDE #

roles/ceph-common/defaults/main.yml

@@ -331,6 +331,20 @@ restapi_port: 5000
 # if you don't want it keep the option commented
 #common_single_host_mode: true
 
+## Handlers - restarting daemons after a config change
+# if for whatever reasons the content of your ceph configuration changes
+# ceph daemons will be restarted as well. At the moment, we can not detect
+# which config option changed so all the daemons will be restarted. Although
+# this restart will be serialized for each node, in between a health check
+# will be performed so we make sure we don't move to the next node until
+# ceph is not healthy
+# Obviously between the checks (for monitors to be in quorum and for osd's pgs
+# to be clean) we have to wait. These retries and delays can be configurable
+# for both monitors and osds.
+handler_health_mon_check_retries: 5
+handler_health_mon_check_delay: 10
+handler_health_osd_check_retries: 40
+handler_health_osd_check_delay: 30
 
 ###################
 # CONFIG OVERRIDE #

roles/ceph-common/handlers/main.yml

@@ -2,41 +2,19 @@
 - name: update apt cache
   apt:
     update-cache: yes
+  when: ansible_os_family == 'Debian'
 
 - name: restart ceph mons
-  service:
-      name: ceph-mon@{{ monitor_name }}
-      state: restarted
-  when:
-    - socket.rc == 0
-    - mon_group_name in group_names
+  include: "{{ playbook_dir }}/roles/ceph-common/handlers/restart-mon.yml"
 
-# This does not just restart OSDs but everything else too. Unfortunately
-# at this time the ansible role does not have an OSD id list to use
-# for restarting them specifically.
 - name: restart ceph osds
-  service:
-    name: ceph.target
-    state: restarted
-  when:
-    - socket.rc == 0
-    - osd_group_name in group_names
+  include: "{{ playbook_dir }}/roles/ceph-common/handlers/restart-osd.yml"
 
 - name: restart ceph mdss
-  service:
-      name: ceph-mds@{{ mds_name }}
-      state: restarted
-  when:
-    - socket.rc == 0
-    - mds_group_name in group_names
+  include: "{{ playbook_dir }}/roles/ceph-common/handlers/restart-mds.yml"
 
 - name: restart ceph rgws
-  service:
-    name: ceph-rgw@{{ ansible_hostname }}
-    state: restarted
-  when:
-    - socketrgw.rc == 0
-    - rgw_group_name in group_names
+  include: "{{ playbook_dir }}/roles/ceph-common/handlers/restart-rgw.yml"
 
 - name: restart ceph nfss
   service:

roles/ceph-common/handlers/restart-mds.yml

@@ -0,0 +1,13 @@
+---
+- name: restart ceph mdss
+  service:
+    name: ceph-mds@{{ mds_name }}
+    state: restarted
+  # serial: 1 would be the proper solution here, but that can only be set on play level
+  # upstream issue: https://github.com/ansible/ansible/issues/12170
+  run_once: true
+  with_items: "{{ groups[mds_group_name] }}"
+  delegate_to: "{{ item }}"
+  when:
+    - socket.rc == 0
+    - mds_group_name in group_names

roles/ceph-common/handlers/restart-mon.yml

@@ -0,0 +1,17 @@
+---
+- name: restart ceph mons
+  service:
+    name: ceph-mon@{{ monitor_name }}
+    state: restarted
+  # serial: 1 would be the proper solution here, but that can only be set on play level
+  # upstream issue: https://github.com/ansible/ansible/issues/12170
+  run_once: true
+  with_items: "{{ groups[mon_group_name] }}"
+  delegate_to: "{{ item }}"
+  when:
+    - socket.rc == 0
+    - mon_group_name in group_names
+
+- name: validate monitors
+  include: validate-mon.yml
+  when: mon_group_name in group_names

roles/ceph-common/handlers/restart-osd.yml

@@ -0,0 +1,22 @@
+---
+# This does not just restart OSDs but everything else too. Unfortunately
+# at this time the ansible role does not have an OSD id list to use
+# for restarting them specifically.
+- name: restart ceph osds
+  shell: |
+    for id in $(ls /var/lib/ceph/osd/ |grep -oh '[0-9]*'); do
+      systemctl restart ceph-osd@$id
+      sleep 5
+    done
+  # serial: 1 would be the proper solution here, but that can only be set on play level
+  # upstream issue: https://github.com/ansible/ansible/issues/12170
+  run_once: true
+  with_items: "{{ groups[osd_group_name] }}"
+  delegate_to: "{{ item }}"
+  when:
+    - socket.rc == 0
+    - osd_group_name in group_names
+
+- name: validate osds
+  include: validate-osd.yml
+  when: osd_group_name in group_names

roles/ceph-common/handlers/restart-rgw.yml

@@ -0,0 +1,13 @@
+---
+- name: restart ceph rgws
+  service:
+    name: ceph-rgw@{{ ansible_hostname }}
+    state: restarted
+  # serial: 1 would be the proper solution here, but that can only be set on play level
+  # upstream issue: https://github.com/ansible/ansible/issues/12170
+  run_once: true
+  with_items: "{{ groups[rgw_group_name] }}"
+  delegate_to: "{{ item }}"
+  when:
+    - socketrgw.rc == 0
+    - rgw_group_name in group_names

roles/ceph-common/handlers/validate-mon.yml

@@ -0,0 +1,28 @@
+---
+- name: wait for ceph monitor socket
+  wait_for:
+    path: "/var/run/ceph/{{ cluster }}-mon.{{ monitor_name }}.asok"
+
+- name: set mon_host_count
+  set_fact: mon_host_count={{ groups[mon_group_name] | length }}
+
+- name: select a running monitor
+  set_fact: mon_host={{ item }}
+  with_items: "{{ groups[mon_group_name] }}"
+  when:
+    - item != inventory_hostname
+    - mon_host_count | int > 1
+
+- name: select first monitor if only one monitor
+  set_fact: mon_host={{ item }}
+  with_items: "{{ groups[mon_group_name][0] }}"
+  when: mon_host_count | int == 1
+
+- name: waiting for the monitor to join the quorum...
+  shell: |
+    ceph -s  --cluster {{ cluster }} | grep monmap | sed 's/.*quorum//' | egrep -sq {{ ansible_hostname }}
+  register: result
+  until: result.rc == 0
+  retries: "{{ handler_health_mon_check_retries }}"
+  delay: "{{ handler_health_mon_check_delay }}"
+  delegate_to: "{{ mon_host }}"

roles/ceph-common/handlers/validate-osd.yml

@@ -0,0 +1,19 @@
+---
+- name: collect osds
+  shell: |
+    ls /var/lib/ceph/osd/ |grep -oh '[0-9]*'
+  register: osd_ids
+
+- name: wait for ceph osd socket(s)
+  wait_for:
+    path: "/var/run/ceph/{{ cluster }}-osd.{{ item }}.asok"
+  with_items: "{{ osd_ids.stdout_lines }}"
+
+- name: waiting for clean pgs...
+  shell: |
+    test "$(ceph --cluster {{ cluster }} pg stat | sed 's/^.*pgs://;s/active+clean.*//;s/ //')" -eq "$(ceph --cluster {{ cluster }} pg stat | sed 's/pgs.*//;s/^.*://;s/ //')" && ceph --cluster {{ cluster }} health | egrep -sq "HEALTH_OK|HEALTH_WARN"
+  register: result
+  until: result.rc == 0
+  retries: "{{ handler_health_osd_check_retries }}"
+  delay: "{{ handler_health_osd_check_delay }}"
+  delegate_to: "{{ groups[mon_group_name][0] }}"

roles/ceph-common/tasks/generate_ceph_conf.yml

@@ -22,3 +22,4 @@
     - restart ceph osds
     - restart ceph mdss
     - restart ceph rgws
+    - restart ceph nfss