Revert - wait for all snapshots to drain before returning (#15)

* Revert - wait for all snapshots to drain before returning

Add a check that the all snapshots were drained
Add test
Add changelog fragement

Signed-off-by: Ygal Blum <[email protected]>

* Wait for drain - filter also by group name

Add group name to the select filter to make sure the returned list has only one result

Co-authored-by: Bob Mader <[email protected]>

---------

Signed-off-by: Ygal Blum <[email protected]>
Co-authored-by: Bob Mader <[email protected]>

changelogs/fragments/revert-wait-for-drain.yml

@@ -0,0 +1,2 @@
+minor_changes:
+  - Revert - wait for snapshot to drain before returning

roles/lvm_snapshots/tasks/revert.yml

@@ -22,3 +22,12 @@
     path: "/root/boot-backup-{{ lvm_snapshots_set_name }}.tgz"
     state: absent
   when: lvm_snapshots_boot_backup
+
+- name: Wait for the snapshot to drain
+  ansible.builtin.command: "lvs --select 'vg_name = {{ item.vg_name }} && lv_name = {{ item.origin }}' --reportformat json"
+  register: _lv_drain_check
+  until: (_lv_drain_check.stdout | from_json).report[0].lv[0].data_percent == ""
+  retries: 20
+  delay: 30
+  loop: "{{ lvm_snapshots_snapshots }}"
+  changed_when: false

tests/fill-snapshot.yml

@@ -0,0 +1,40 @@
+- name: Fill the volume
+  block:
+  - name: Set the retry count
+    ansible.builtin.set_fact:
+      _retry_count: "{{ (_retry_count | default('-1') | int) + 1 }}"
+
+  - name: Generate the Sub-Directory name
+    ansible.builtin.set_fact:
+      _sub_dir_name: "{{ lookup('community.general.random_string', upper=false, numbers=false, special=false) }}"
+
+  - name: Make a copy of the boot partition
+    ansible.builtin.copy:
+      src: /boot
+      dest: "{{ test_directory }}/{{ _sub_dir_name }}"
+      remote_src: true
+      mode: '0777'
+
+  - name: Get the status of the snapshot
+    ansible.builtin.command: "lvs --select 'lv_name = {{ volume_name }}_{{ snapshot_set_name }}' --reportformat json"
+    register: _lv_status_check
+    changed_when: false
+
+  - name: Store the snapshot data_percent
+    ansible.builtin.set_fact:
+      _snapshot_data_percent: "{{ ((_lv_status_check.stdout | from_json).report[0].lv[0].data_percent) }}"
+
+  - name: Check if snapshot is full enough
+    ansible.builtin.assert:
+      that: _snapshot_data_percent|float > snapshot_fill_percent|float
+      quiet: true
+
+  rescue:
+  - name: Check the retry count to avoid endless loop
+    ansible.builtin.assert:
+      that: (_retry_count|int) < (snapshot_max_retry|int)
+      fail_msg: "Ended after {{ snapshot_max_retry }} retries"
+      success_msg: "Volume is not full enought ({{ _snapshot_data_percent }}) - Run again..."
+
+  - name: Include the same tasks file again
+    ansible.builtin.include_tasks: fill-snapshot.yml

tests/test-drain-snapshot.yml

@@ -0,0 +1,53 @@
+- name: Test revering to the snapshots
+  hosts: all
+  become: true
+  vars:
+    volume_group: test_vg
+    test_directory: "/mnt/test"
+    volume_name: test_lv
+    volumes:
+    - name: "{{ volume_name }}"
+      size: 4g
+      directory: "{{ test_directory }}"
+    snapshot_set_name: demo_snap
+    snapshot_fill_percent: 60
+    snapshot_max_retry: 100
+  tasks:
+  - name: Run pre-test steps
+    ansible.builtin.include_tasks: pre-test-tasks.yml
+
+  - name: Create the snapshot
+    ansible.builtin.include_tasks: create-snapshot.yml
+
+  - name: Fill the snapshot
+    ansible.builtin.include_tasks: fill-snapshot.yml
+
+  - name: Revert to Snapshot
+    vars:
+      lvm_snapshots_action: revert
+      lvm_snapshots_set_name: "{{ snapshot_set_name }}"
+    ansible.builtin.include_role:
+      name: lvm_snapshots
+
+  - name: Verify that the snapshot was completly drained
+    block:
+    - name: Verify that the snapshot no longer exists
+      vars:
+        volume_name: test_lv
+      ansible.builtin.include_tasks: verify-snapshot-not-exist.yml
+    - name: Verify that the snapshot was drained before returning
+      block:
+      - name: Get the status of the volume
+        ansible.builtin.command: "lvs --select 'lv_name = {{ volume_name }}' --reportformat json"
+        register: _lv_status_check
+        changed_when: false
+      - name: Store the snapshot data_percent
+        ansible.builtin.set_fact:
+          volume_data_percent: "{{ ((_lv_status_check.stdout | from_json).report[0].lv[0].data_percent) }}"
+      - name: Assert volume_data_percent is 0
+        ansible.builtin.assert:
+          that: volume_data_percent|float == 0.0
+          fail_msg: "Volume data percent is {{ volume_data_percent }} while it should be 0"
+    always:
+    - name: Cleanup
+      ansible.builtin.include_tasks: post-test-tasks.yml