Create LVM on loop device to deploy Openshift Storage

The Openshift Storage that uses topolvm was raising an error, because
the Microshift host does not have any LVM device. In previous role
stage, we just remove the openshift-storage namespace and storageclass,
because the CI tests mostly were using local storage for PV.

defaults/main.yaml

@@ -32,5 +32,9 @@ standard_user:
   namespace: dev-admin
   role: admin
 
-delete_openshift_storage: true
+delete_openshift_storage: false
+disk_file_path: /mnt/microshift-storage-file
+disk_file_size: 20G
+vg_name: rhel
+
 overwrite_container_policy: false

tasks/main.yaml

@@ -47,6 +47,5 @@
   ansible.builtin.include_tasks: standard-user.yaml
   when: standard_user
 
-- name: Delete openshift storage
+- name: Create lvm or delete openshift storage
   ansible.builtin.include_tasks: openshift-storage.yaml
-  when: delete_openshift_storage

tasks/openshift-storage.yaml

@@ -1,15 +1,69 @@
 ---
-# NOTE: The Openshift storage uses topolvm, that requires additional volume,
-# which is not necessary for us, due we mostly use that playbook for CI.
-- name: Check if openshift-storage namespace exists
-  ansible.builtin.command: oc get namespace openshift-storage
-  register: _openshift_storage_ns
-  failed_when: _openshift_storage_ns.rc not in [0, 1]
-
-- name: Delete openshift storage namespace
-  ansible.builtin.command: oc delete namespace openshift-storage
-  when: _openshift_storage_ns.rc == 0
-
-- name: Delete topolvm-provisioner storageclass
-  ansible.builtin.command: oc delete storageclass topolvm-provisioner
-  when: _openshift_storage_ns.rc == 0
+- name: Delete openshift-storage if needed
+  when: delete_openshift_storage
+  block:
+    # NOTE: The Openshift storage uses topolvm, that requires additional volume,
+    # which is not necessary for us, due we mostly use that playbook for CI.
+    - name: Check if openshift-storage namespace exists
+      ansible.builtin.command: oc get namespace openshift-storage
+      register: _openshift_storage_ns
+      failed_when: _openshift_storage_ns.rc not in [0, 1]
+
+    - name: Delete openshift storage namespace
+      ansible.builtin.command: oc delete namespace openshift-storage
+      when: _openshift_storage_ns.rc == 0
+
+    - name: Delete topolvm-provisioner storageclass
+      ansible.builtin.command: oc delete storageclass topolvm-provisioner
+      when: _openshift_storage_ns.rc == 0
+
+- name: Create LVM on loop device to deploy openshift storage with topolvm
+  when: not delete_openshift_storage
+  block:
+    - name: Check if file already exists
+      become: true
+      stat:
+        path: "{{ disk_file_path }}"
+      register: _disk_file
+
+    - name: Create loop disk
+      when: not _disk_file.stat.exists
+      block:
+        - name: Create empty file
+          become: true
+          community.general.filesize:
+            path: "{{ disk_file_path }}"
+            size: "{{ disk_file_size }}"
+
+        - name: Make partition on empty file
+          become: true
+          community.general.parted:
+            device: "{{ disk_file_path }}"
+            number: 1
+            state: present
+            flags: ["lvm"]
+
+        - name: Get first available loop device
+          become: true
+          ansible.builtin.command: losetup -f
+          register: loop_device
+
+        - name: Create loop device service
+          become: true
+          ansible.builtin.template:
+            src: microshift-loop-device.service.j2
+            dest: /usr/lib/systemd/system/microshift-loop-device.service
+
+        - name: Enable loop device service
+          become: true
+          ansible.builtin.systemd:
+            name: microshift-loop-device
+            state: started
+            enabled: true
+            daemon_reload: true
+
+        - name: Create volume group
+          become: true
+          community.general.lvg:
+            vg: "{{ vg_name }}"
+            pvs: "{{ loop_device.stdout }}"

tasks/pre.yaml

@@ -12,6 +12,7 @@
       - git
       - golang
       - python3-cryptography
+      - lvm2
     state: present
 
 - name: Add host to the hosts file

templates/microshift-loop-device.service.j2

@@ -0,0 +1,16 @@
+[Unit]
+Description=Setup loopback device
+DefaultDependencies=no
+Conflicts=umount.target
+Before=local-fs.target umount.target microshift.service
+
+[Service]
+ExecStart=/sbin/losetup {{ loop_device.stdout }} {{ disk_file_path }}
+ExecStop=/sbin/losetup -d {{ loop_device.stdout }}
+Type=oneshot
+TimeoutSec=60
+RemainAfterExit=yes
+
+[Install]
+WantedBy=local-fs-pre.target
+Also=systemd-udevd.service