ceph-ansible/infrastructure-playbooks/shrink-osd.yml

---
# This playbook shrinks Ceph OSDs that have been created with ceph-volume.
# It can remove any number of OSD(s) from the cluster and ALL THEIR DATA
#
# Use it like this:
# ansible-playbook lvm-shrink-osd.yml -e osd_to_kill=0,2,6
#     Prompts for confirmation to shrink, defaults to no and
#     doesn't shrink the cluster. yes shrinks the cluster.
#
# ansible-playbook -e ireallymeanit=yes|no lvm-shrink-osd.yml
#     Overrides the prompt using -e option. Can be used in
#     automation scripts to avoid interactive prompt.

- name: gather facts and check the init system

  hosts:
    - "{{ mon_group_name|default('mons') }}"
    - "{{ osd_group_name|default('osds') }}"

  become: True
  tasks:
    - debug: msg="gather facts on all Ceph hosts for following reference"

- name: confirm whether user really meant to remove osd(s) from the cluster

  hosts:
    - localhost

  become: true

  vars_prompt:
    - name: ireallymeanit
      prompt: Are you sure you want to shrink the cluster?
      default: 'no'
      private: no

  vars:
    mon_group_name: mons
    osd_group_name: osds

  pre_tasks:
    - name: exit playbook, if user did not mean to shrink cluster
      fail:
        msg: "Exiting shrink-osd playbook, no osd(s) was/were removed..
           To shrink the cluster, either say 'yes' on the prompt or
           or use `-e ireallymeanit=yes` on the command line when
           invoking the playbook"
      when: ireallymeanit != 'yes'

    - name: exit playbook, if no osd(s) was/were given
      fail:
        msg: "osd_to_kill must be declared
          Exiting shrink-osd playbook, no OSD(s) was/were removed.
           On the command line when invoking the playbook, you can use
           -e osd_to_kill=0,1,2,3 argument."
      when: osd_to_kill is not defined

  tasks:
    - import_role:
        name: ceph-defaults

  post_tasks:
    - name: set_fact docker_exec_cmd build docker exec command (containerized)
      set_fact:
        docker_exec_cmd: "{{ container_binary }} exec ceph-mon-{{ hostvars[groups[mon_group_name][0]]['ansible_hostname'] }}"
      when: containerized_deployment

    - name: exit playbook, if can not connect to the cluster
      command: "{{ docker_exec_cmd }} timeout 5 ceph --cluster {{ cluster }} health"
      register: ceph_health
      until: ceph_health.stdout.find("HEALTH") > -1
      delegate_to: "{{ groups[mon_group_name][0] }}"
      retries: 5
      delay: 2

    - name: find the host(s) where the osd(s) is/are running on
      command: "{{ docker_exec_cmd }} ceph --cluster {{ cluster }} osd find {{ item }}"
      with_items: "{{ osd_to_kill.split(',') }}"
      delegate_to: "{{ groups[mon_group_name][0] }}"
      register: find_osd_hosts

    - name: set_fact osd_hosts
      set_fact:
        osd_hosts: "{{ osd_hosts | default([]) + [ (item.stdout | from_json).crush_location.host ] }}"
      with_items: "{{ find_osd_hosts.results }}"

    - name: find lvm osd volumes on each host
      ceph_volume:
        action: "list"
      environment:
        CEPH_VOLUME_DEBUG: 1
        CEPH_CONTAINER_IMAGE: "{{ ceph_docker_registry + '/' + ceph_docker_image + ':' + ceph_docker_image_tag if containerized_deployment else None }}"
        CEPH_CONTAINER_BINARY: "{{ container_binary }}"
      with_items: "{{ osd_hosts }}"
      delegate_to: "{{ item }}"
      register: osd_volumes

    - name: filter osd volumes to kill by osd - non container
      set_fact:
        osd_volumes_to_kill_non_container: "{{ osd_volumes_to_kill_non_container | default([]) + [ (item.1.stdout|from_json)[item.0] ] }}"
      with_together:
        - "{{ osd_to_kill.split(',') }}"
        - "{{ osd_volumes.results }}"

    - name: generate (host / volume) pairs to zap - non container
      set_fact:
        osd_host_volumes_to_kill_non_container: "{%- set _val = namespace(devs=[]) -%}
        {%- for host in osd_hosts -%}
        {%- for dev in osd_volumes_to_kill_non_container[loop.index-1] -%}
        {%- set _val.devs = _val.devs + [{\"host\": host, \"path\": dev.path}] -%}
        {%- endfor -%}
        {%- endfor -%}
        {{ _val.devs }}"

    - name: mark osd(s) out of the cluster
      command: "{{ docker_exec_cmd }} ceph --cluster {{ cluster }} osd out {{ item }}"
      run_once: true
      delegate_to: "{{ groups[mon_group_name][0] }}"
      with_items: "{{ osd_to_kill.split(',') }}"

    - name: stop osd(s) service
      service:
        name: ceph-osd@{{ item.0 }}
        state: stopped
        enabled: no
      with_together:
        - "{{ osd_to_kill.split(',') }}"
        - "{{ osd_hosts }}"
      delegate_to: "{{ item.1 }}"

    - name: zap osd devices
      ceph_volume:
        action: "zap"
        data: "{{ item.path }}"
      environment:
        CEPH_VOLUME_DEBUG: 1
        CEPH_CONTAINER_IMAGE: "{{ ceph_docker_registry + '/' + ceph_docker_image + ':' + ceph_docker_image_tag if containerized_deployment else None }}"
        CEPH_CONTAINER_BINARY: "{{ container_binary }}"
      delegate_to: "{{ item.host }}"
      with_items: "{{ osd_host_volumes_to_kill_non_container }}"

    - name: purge osd(s) from the cluster
      command: "{{ docker_exec_cmd }} ceph --cluster {{ cluster }} osd purge {{ item }} --yes-i-really-mean-it"
      run_once: true
      delegate_to: "{{ groups[mon_group_name][0] }}"
      with_items: "{{ osd_to_kill.split(',') }}"

    - name: show ceph health
      command: "{{ docker_exec_cmd }} ceph --cluster {{ cluster }} -s"
      delegate_to: "{{ groups[mon_group_name][0] }}"

    - name: show ceph osd tree
      command: "{{ docker_exec_cmd }} ceph --cluster {{ cluster }} osd tree"
      delegate_to: "{{ groups[mon_group_name][0] }}"