Merge pull request #1 from kilnfi/feat/autodectect-raid-members

Add auto-detection feature for RAID array creation

Author: rguichard

README.md

@@ -17,15 +17,41 @@ None
 
 ## Example Playbook
 
+### Manual configuration
 ```yaml
 - hosts: all
   become: true
   vars:
+    mdadm_arrays:
+      - name: md200
+        devices:
+          - /dev/nvme0n1
+          - /dev/nvme1n1
+        filesystem: lvm
+        level: 5
+        state: present
   roles:
     - role: ansible-mdadm
-  tasks:
 ```
 
+### Auto-detection mode
+```yaml
+- hosts: all
+  become: true
+  vars:
+    mdadm_auto_detect_arrays: true
+    mdadm_auto_detect_config:
+      - name: md200
+        filesystem: lvm
+        level: 5
+        state: present
+        min_disks: 3
+  roles:
+    - role: ansible-mdadm
+```
+
+Note: Auto-detection will automatically use all unused disks (not mounted, not in RAID, not in LVM, not formatted) if `mdadm_arrays` is empty and `mdadm_auto_detect_arrays` is true.
+
 ## License
 
 BSD

defaults/main.yml

@@ -35,3 +35,14 @@
 #   mountpoint: '/mnt/md0'
 #   state: 'present'
 mdadm_arrays: []
+
+# Auto-detection settings
+mdadm_auto_detect_arrays: false
+mdadm_auto_detect_config:
+  # Default configuration for auto-detected arrays
+  - name: md200
+    filesystem: lvm
+    level: 5
+    state: present
+    # Minimum number of disks required for auto-detection
+    min_disks: 3

tasks/detect_unused_disks.yml

@@ -0,0 +1,48 @@
+---
+# Detect unused disks that can be used for RAID arrays
+# This task will identify disks that are:
+# - Not mounted
+# - Not part of existing RAID arrays
+# - Not used in LVM
+# - Not formatted with a filesystem
+
+- name: detect_unused_disks | Get all block devices
+  shell: lsblk -ln -o NAME,TYPE,MOUNTPOINT,FSTYPE | grep -E '^[a-z]+[0-9]*\s+disk\s*$' | awk '{print "/dev/" $1}'
+  register: all_disks
+  changed_when: false
+
+- name: detect_unused_disks | Get mounted devices
+  shell: mount | awk '{print $1}' | grep '^/dev/' | sort | uniq
+  register: mounted_devices
+  changed_when: false
+
+- name: detect_unused_disks | Get devices used in existing RAID arrays
+  shell: cat /proc/mdstat | grep -oE 'sd[a-z]+[0-9]*|nvme[0-9]+n[0-9]+' | sed 's|^|/dev/|' | sort | uniq
+  register: raid_devices
+  changed_when: false
+  failed_when: false
+
+- name: detect_unused_disks | Get devices used in LVM
+  shell: pvs --noheadings -o pv_name 2>/dev/null | tr -d ' ' | sort | uniq
+  register: lvm_devices
+  changed_when: false
+  failed_when: false
+
+- name: detect_unused_disks | Get devices with filesystem
+  shell: blkid | cut -d: -f1 | sort | uniq
+  register: formatted_devices
+  changed_when: false
+  failed_when: false
+
+- name: detect_unused_disks | Filter unused disks
+  set_fact:
+    unused_disks: "{{ all_disks.stdout_lines | 
+      difference(mounted_devices.stdout_lines | default([])) |
+      difference(raid_devices.stdout_lines | default([])) |
+      difference(lvm_devices.stdout_lines | default([])) |
+      difference(formatted_devices.stdout_lines | default([])) }}"
+
+- name: detect_unused_disks | Debug unused disks found
+  debug:
+    msg: "Unused disks detected: {{ unused_disks }}"
+  when: unused_disks | length > 0

tasks/main.yml

@@ -12,4 +12,18 @@
   when: >
         mdadm_force_wipe is defined and
         mdadm_force_wipe
+
+- include_tasks: detect_unused_disks.yml
+  when: >
+        mdadm_auto_detect_arrays and
+        (mdadm_arrays | length == 0)
+
+- name: main | Set auto-detected arrays
+  set_fact:
+    mdadm_arrays: "{{ mdadm_auto_detect_config | map('combine', {'devices': unused_disks}) | list }}"
+  when: >
+        mdadm_auto_detect_arrays and
+        (mdadm_arrays | length == 0) and
+        (unused_disks | length >= mdadm_auto_detect_config[0].min_disks)
+
 - include_tasks: arrays.yml