Add lvol module to manage logical volumes.

library/lvol

+#!/usr/bin/python
+# -*- coding: utf-8 -*-
+
+# (c) 2013, Jeroen Hoekx <jeroen.hoekx@dsquare.be>
+#
+# This file is part of Ansible
+#
+# Ansible is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# Ansible is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
+
+DOCUMENTATION = '''
+---
+author: Jeroen Hoekx
+module: lvol
+short_description: Configure LVM logical volumes
+description:
+  - This module creates, removes or resizes logical volumes.
+version_added: "1.1"
+options:
+  vg:
+    description:
+    - The volume group this logical volume is part of.
+    required: true
+  lv:
+    description:
+    - The name of the logical volume.
+    required: true
+  size:
+    description:
+    - The size of the logical volume in megabytes.
+  state:
+    choices: [ "present", "absent" ]
+    default: present
+    description:
+    - Control if the logical volume exists.
+    required: false
+examples:
+  - description: Create a logical volume of 512m.
+    code: lvol vg=firefly lv=test size=512
+  - description: Extend the logical volume to 1024m.
+    code: lvol vg=firefly lv=test size=1024
+  - description: Reduce the logical volume to 512m
+    code: lvol vg=firefly lv=test size=512
+  - description: Remove the logical volume.
+    code: lvol vg=firefly lv=test state=absent
+notes:
+  - Filesystems on top of the volume are not resized.
+'''
+
+def parse_lvs(data):
+    lvs = []
+    for line in data.splitlines():
+        parts = line.strip().split(';')
+        lvs.append({
+            'name': parts[0],
+            'size': int(parts[1].split('.')[0]),
+            'path': parts[2],
+        })
+    return lvs
+
+def main():
+    module = AnsibleModule(
+        argument_spec = dict(
+            vg=dict(required=True),
+            lv=dict(required=True),
+            size=dict(),
+            state=dict(choices=["absent", "present"], default='present'),
+        ),
+        supports_check_mode=True,
+    )
+
+    vg = module.params['vg']
+    lv = module.params['lv']
+    size = module.params['size']
+    state = module.params['state']
+
+    if state=='present' and not size:
+        module.fail_json(msg="No size given.")
+
+    if size:
+        size = int(size)
+
+    rc,current_lvs,err = module.run_command("lvs --noheadings -o lv_name,size,lv_path --units m --separator ';' %s"%(vg))
+
+    if rc != 0:
+        module.fail_json(msg="Volume group %s does not exist."%vg, rc=rc, err=err)
+
+    changed = False
+
+    lvs = parse_lvs(current_lvs)
+
+    for test_lv in lvs:
+        if test_lv['name'] == lv:
+            this_lv = test_lv
+            break
+    else:
+        this_lv = None
+
+    if this_lv is None:
+        if state == 'present':
+            ### create LV
+            if module.check_mode:
+                changed = True
+            else:
+                rc,_,err = module.run_command("lvcreate -n %s -L %sm %s"%(lv, size, vg))
+                if rc == 0:
+                    changed = True
+                else:
+                    module.fail_json(msg="Creating logical volume '%s' failed"%(lv), rc=rc, err=err)
+    else:
+        if state == 'absent':
+            ### remove LV
+            if module.check_mode:
+                module.exit_json(changed=True)
+            rc,_,err = module.run_command("lvremove --force %s"%(this_lv['path']))
+            if rc == 0:
+                module.exit_json(changed=True)
+            else:
+                module.fail_json(msg="Failed to remove logical volume %s"%(lv),rc=rc, err=err)
+        ### resize LV
+        tool = None
+        if size > this_lv['size']:
+            tool = 'lvextend'
+        elif size < this_lv['size']:
+            tool = 'lvreduce --force'
+
+        if tool:
+            if module.check_mode:
+                changed = True
+            else:
+                rc,_,err = module.run_command("%s -L %sm %s"%(tool, size, this_lv['path']))
+                if rc == 0:
+                    changed = True
+                else:
+                    module.fail_json(msg="Unable to resize %s to %sm."%(lv,size),rc=rc,err=err)
+
+    module.exit_json(changed=changed)
+
+# this is magic, see lib/ansible/module_common.py
+#<<INCLUDE_ANSIBLE_MODULE_COMMON>>
+main()