[ceph] Add thin-provisioned LV support for Ceph OSDs

docs/dictionary/en-custom.txt

@@ -16,6 +16,7 @@ IdP
 Idempotency
 LDAP
 LLM
+LVs
 MachineConfig
 Marjanovic
 Nemanja

hooks/playbooks/ceph.yml

@@ -159,6 +159,9 @@
             hostvars[_target]['ansible_ssh_private_key_file'] |
             default(lookup('env', 'ANSIBLE_SSH_PRIVATE_KEY'))
           }}
+        cifmw_block_device_thin_pool: "{{ cifmw_ceph_thin_pool | default('') }}"
+        cifmw_block_device_thin_lv_size: "{{ cifmw_ceph_thin_lv_size | default('50G') }}"
+        cifmw_block_device_thin_lv_name: "ceph_osd_{{ i }}"
         cifmw_block_device_image_file: /var/lib/ceph-osd-{{ i }}.img
         cifmw_block_device_loop: /dev/loop{{ i + 3 }}
         cifmw_block_lv_name: ceph_lv{{ i }}
@@ -170,6 +173,17 @@
         loop_var: i
       loop: "{{ range(0, cifmw_num_osds_perhost|int) }}"
 
+    - name: Build data_devices for ceph spec from cifmw_block_device outputs
+      ansible.builtin.set_fact:
+        cifmw_ceph_spec_data_devices: |
+          data_devices:
+            paths:
+          {% for p in cifmw_block_device_paths %}
+              - {{ p }}
+          {% endfor %}
+      delegate_to: localhost
+      delegate_facts: true
+
 - name: Build Ceph spec and conf from gathered IPs of the target inventory group
   tags: spec
   hosts: localhost

roles/cifmw_block_device/README.md

@@ -1,25 +1,31 @@
 # cifmw_block_device
 
-Creates a virtual block device with logical volumes. Useful for
-deploying Ceph on a virtual machine which does not have any
-block devices except for root. Creates a systemd unit so the
-virtual block device comes back online during reboot.
+Creates block devices with logical volumes for Ceph OSD testing.
+Supports two modes:
 
-The target system must have 7 GB of available disk space at minimum.
+- **Loop mode** (default): creates a loop-backed file with LVM on top
+  and a systemd unit to restore it across reboots. Useful for VMs
+  that have no spare block devices.
+- **Thin-pool mode**: creates thin-provisioned LVs from an existing
+  VG thin pool. Useful for bare-metal hosts that already have a
+  thin pool with available space.
 
-This role will recreate the block device on each run. Thus, if there
-is data on the block device from the previous run it will delete it.
-The assumption is that the block device exists for testing and that
-rebuilding the environment quickly is more important preserving any
-test data.
+The mode is selected by `cifmw_block_device_thin_pool`: when non-empty
+the role uses thin-pool mode, otherwise loop mode.
 
 ## Privilege escalation
 
-Requires root on the remote system to create loop back device and
-systemd unit.
+Requires root on the remote system to create devices and LVM objects.
 
 ## Parameters
 
+### Common
+
+* `cifmw_block_device_thin_pool`: VG/pool path for thin-pool mode,
+  e.g. `vg/lv_thinpool`. When empty (default), loop mode is used.
+
+### Loop mode
+
 * `cifmw_block_device_image_file`: Name of the `dd'd` image file
   (default `/var/lib/ceph-osd.img`)
 * `cifmw_block_device_size`: Size of the virtual block device (default
@@ -34,8 +40,25 @@ systemd unit.
   restores the device on system startup (default
   `/etc/systemd/system/ceph-osd-losetup.service`)
 
+### Thin-pool mode
+
+* `cifmw_block_device_thin_lv_size`: Size of each thin LV (default
+  `50G`)
+* `cifmw_block_device_thin_lv_name`: Name of the thin LV to create
+  (default `ceph_osd`)
+
+## Output
+
+Both modes append to the `cifmw_block_device_paths` list fact.
+Each role invocation adds one entry, so when called in a loop
+the list accumulates all created device paths (e.g.
+`["/dev/ceph_vg0/ceph_lv0", "/dev/ceph_vg1/ceph_lv1"]` or
+`["/dev/vg/ceph_osd_0", "/dev/vg/ceph_osd_1"]`).
+
 ## Examples
 
+### Loop mode (default)
+
 The following will create a 7 GB block device on the target system
 using the defaults above.
 ```
@@ -60,11 +83,30 @@ data_devices:
   paths:
   - /dev/ceph_vg/ceph_lv_data
 ```
-The following will stop and disable the systemd unit file which starts
-the virtual block device, remove the logical volume, volume group, and
-physical volume, and delete the loopback device and its backing file.
+
+### Thin-pool mode
+
+```yaml
+- include_role:
+    name: cifmw_block_device
+  vars:
+    cifmw_block_device_thin_pool: "vg/lv_thinpool"
+    cifmw_block_device_thin_lv_size: "50G"
+    cifmw_block_device_thin_lv_name: "ceph_osd_0"
+```
+Ceph spec entry:
+```yaml
+data_devices:
+  paths:
+  - /dev/vg/ceph_osd_0
 ```
+
+### Cleanup
+
+```yaml
 - import_role:
     name: cifmw_block_device
     tasks_from: cleanup
 ```
+For thin-pool mode, pass `cifmw_block_device_thin_pool` and
+`cifmw_block_device_thin_lv_name` so the correct cleanup path runs.

roles/cifmw_block_device/defaults/main.yml

@@ -18,9 +18,17 @@
 # All variables intended for modification should be placed in this file.
 # All variables within this role should have a prefix of "cifmw_block_device"
 
+# --- Loop-device mode (default) ---
 cifmw_block_device_image_file: /var/lib/ceph-osd.img
 cifmw_block_device_size: 7G
 cifmw_block_device_loop: /dev/loop3
 cifmw_block_vg_name: ceph_vg
 cifmw_block_lv_name: ceph_lv_data
 cifmw_block_systemd_unit_file: /etc/systemd/system/ceph-osd-losetup.service
+
+# --- Thin-pool mode ---
+# When non-empty, create thin-provisioned LVs from this existing thin pool
+# instead of loop-backed files.  Value is "VG/pool", e.g. "vg/lv_thinpool".
+cifmw_block_device_thin_pool: ""
+cifmw_block_device_thin_lv_size: "50G"
+cifmw_block_device_thin_lv_name: "ceph_osd"

roles/cifmw_block_device/tasks/cleanup.yml

@@ -14,31 +14,47 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-- name: Ensure ceph-osd-losetup is not running and disabled
-  tags: systemd
+- name: Clean up thin-provisioned LV
+  when: cifmw_block_device_thin_pool | length > 0
   become: true
-  ansible.builtin.systemd:
-    state: stopped
-    enabled: false
-    name: "{{ cifmw_block_systemd_unit_file | basename }}"
+  ansible.builtin.command:
+    cmd: >-
+      lvremove --force
+      /dev/{{ cifmw_block_device_thin_pool.split('/')[0] }}/{{ cifmw_block_device_thin_lv_name }}
+  register: _thin_cleanup
+  failed_when:
+    - _thin_cleanup.rc != 0
+    - "'not found' not in (_thin_cleanup.stderr | default(''))"
 
-- name: Remove unit file
-  become: true
-  ansible.builtin.file:
-    path: "{{ cifmw_block_systemd_unit_file }}"
-    state: absent
+- name: Clean up loop-backed block device
+  when: cifmw_block_device_thin_pool | default('') | length == 0
+  block:
+    - name: Ensure ceph-osd-losetup is not running and disabled
+      tags: systemd
+      become: true
+      ansible.builtin.systemd:
+        state: stopped
+        enabled: false
+        name: "{{ cifmw_block_systemd_unit_file | basename }}"
 
-- name: Use {pv,vg,lv}remove to remove logical volume on loop device
-  become: true
-  ansible.builtin.shell:
-    cmd: |-
-      lvremove --force /dev/{{ cifmw_block_vg_name }}/{{ cifmw_block_lv_name }}
-      vgremove --force {{ cifmw_block_vg_name }}
-      pvremove --force {{ cifmw_block_device_loop }}
-      lvs
+    - name: Remove unit file
+      become: true
+      ansible.builtin.file:
+        path: "{{ cifmw_block_systemd_unit_file }}"
+        state: absent
+
+    - name: Use {pv,vg,lv}remove to remove logical volume on loop device
+      become: true
+      ansible.builtin.shell:
+        cmd: |-
+          lvremove --force /dev/{{ cifmw_block_vg_name }}/{{ cifmw_block_lv_name }}
+          vgremove --force {{ cifmw_block_vg_name }}
+          pvremove --force {{ cifmw_block_device_loop }}
+          lvs
 
-- name: Use losetup and rm to cremove the loop device and backing image file
+- name: Use losetup and rm to remove the loop device and backing image file
   become: true
+  when: cifmw_block_device_thin_pool | length > 0
   ansible.builtin.shell:
     cmd: |-
       losetup -d {{ cifmw_block_device_loop }}

roles/cifmw_block_device/tasks/loop.yml

@@ -0,0 +1,74 @@
+---
+# Copyright Red Hat, Inc.
+# All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you may
+# not use this file except in compliance with the License. You may obtain
+# a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+# License for the specific language governing permissions and limitations
+# under the License.
+
+- name: Install packages
+  become: true
+  ansible.builtin.dnf:
+    name:
+      - util-linux
+      - lvm2
+      - jq
+      - podman
+    state: present
+
+- name: Stat loop device see if it already exists
+  ansible.builtin.stat:
+    path: "{{ cifmw_block_device_loop }}"
+  register: cifmw_block_device_loop_res
+
+- name: Log to syslog if loop device exists
+  community.general.syslogger:
+    msg: "Warning {{ cifmw_block_device_loop }} already exists"
+  when: cifmw_block_device_loop_res.stat.exists
+
+- name: Use dd and losetup to create the loop device
+  become: true
+  ansible.builtin.shell:
+    cmd: |-
+      dd if=/dev/zero of={{ cifmw_block_device_image_file }} bs=1 count=0 seek={{ cifmw_block_device_size }}
+      losetup {{ cifmw_block_device_loop }} {{ cifmw_block_device_image_file }}
+      lsblk
+
+- name: Use {pv,vg,lv}create to create logical volume on loop device
+  become: true
+  ansible.builtin.shell:
+    cmd: |-
+      pvcreate {{ cifmw_block_device_loop }}
+      vgcreate {{ cifmw_block_vg_name }} {{ cifmw_block_device_loop }}
+      lvcreate -n {{ cifmw_block_lv_name }} -l +100%FREE {{ cifmw_block_vg_name }}
+      lvs
+
+- name: Create a systemd service that restores the device on startup
+  become: true
+  ansible.builtin.template:
+    src: templates/ceph-osd-losetup.service.j2
+    dest: "{{ cifmw_block_systemd_unit_file }}"
+    mode: "0644"
+    force: true
+
+- name: Ensure ceph-osd-losetup is running and enabled
+  become: true
+  tags: systemd
+  ansible.builtin.systemd:
+    state: started
+    enabled: true
+    name: "{{ cifmw_block_systemd_unit_file | regex_replace('/etc/systemd/system/', '') }}"
+
+- name: Collect created device path
+  ansible.builtin.set_fact:
+    cifmw_block_device_paths: >-
+      {{ (cifmw_block_device_paths | default([])) +
+         ['/dev/' ~ cifmw_block_vg_name ~ '/' ~ cifmw_block_lv_name] }}

roles/cifmw_block_device/tasks/main.yml

@@ -14,55 +14,10 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
-- name: Install packages
-  become: true
-  ansible.builtin.dnf:
-    name:
-      - util-linux
-      - lvm2
-      - jq
-      - podman
-    state: present
+- name: Create block device using thin-pool LV
+  when: cifmw_block_device_thin_pool | length > 0
+  ansible.builtin.include_tasks: thin.yml
 
-- name: Stat loop device see if it already exists
-  ansible.builtin.stat:
-    path: "{{ cifmw_block_device_loop }}"
-  register: cifmw_block_device_loop_res
-
-- name: Log to syslog if loop device exists
-  community.general.syslogger:
-    msg: "Warning {{ cifmw_block_device_loop }} already exists"
-  when: cifmw_block_device_loop_res.stat.exists
-
-- name: Use dd and losetup to create the loop device
-  become: true
-  ansible.builtin.shell:
-    cmd: |-
-      dd if=/dev/zero of={{ cifmw_block_device_image_file }} bs=1 count=0 seek={{ cifmw_block_device_size }}
-      losetup {{ cifmw_block_device_loop }} {{ cifmw_block_device_image_file }}
-      lsblk
-
-- name: Use {pv,vg,lv}create to create logical volume on loop device
-  become: true
-  ansible.builtin.shell:
-    cmd: |-
-      pvcreate {{ cifmw_block_device_loop }}
-      vgcreate {{ cifmw_block_vg_name }} {{ cifmw_block_device_loop }}
-      lvcreate -n {{ cifmw_block_lv_name }} -l +100%FREE {{ cifmw_block_vg_name }}
-      lvs
-
-- name: Create a systemd service that restores the device on startup
-  become: true
-  ansible.builtin.template:
-    src: templates/ceph-osd-losetup.service.j2
-    dest: "{{ cifmw_block_systemd_unit_file }}"
-    mode: "0644"
-    force: true
-
-- name: Ensure ceph-osd-losetup is running and enabled
-  become: true
-  tags: systemd
-  ansible.builtin.systemd:
-    state: started
-    enabled: true
-    name: "{{ cifmw_block_systemd_unit_file | regex_replace('/etc/systemd/system/', '') }}"
+- name: Create block device using loop-backed file
+  when: cifmw_block_device_thin_pool | length == 0
+  ansible.builtin.include_tasks: loop.yml