various fixes in lvg module, added ability to reduce and extend VG, added…

various fixes in lvg module, added ability to reduce and extend VG, added Physical Extent parameter, added explicit creation of physical volumes

library/lvg

@@ -25,7 +25,7 @@ author: Alexander Bulimov
 module: lvg
 short_description: Configure LVM volume groups
 description:
-  - This module creates or removes volume groups.
+  - This module creates, removes or resizes volume groups.
 version_added: "1.1"
 options:
   vg:
@@ -36,6 +36,11 @@ options:
     description:
     - List of comma-separated devices to use in this volume group.
     required: true
+  pesize:
+    description:
+    - The size of the physical extent in megabytes.
+    default: 4
+    required: false
   state:
     choices: [ "present", "absent" ]
     default: present
@@ -44,19 +49,19 @@ options:
     required: false
   force:
     choices: [ "yes", "no" ]
-    default: no
+    default: "no"
     description:
     - If yes, allows to remove volume group with logical volumes.
     required: false
 examples:
-  - description: Create a volume group on top of /dev/sda1.
-    code: lvg vg=vg.services dev=/dev/sda1
+  - description: Create a volume group on top of /dev/sda1 with physical extent size = 32MB.
+    code: lvg vg=vg.services dev=/dev/sda1 pesize=32
   - description: Create a volume group on top of /dev/sdb1 and /dev/sdc5.
     code: lvg vg=vg.services dev=/dev/sdb1,/dev/sdc5
   - description: Remove a volume group with name vg.services.
     code: lvg vg=vg.services state=absent
 notes:
-  - module does not check device list for already present volume group
+  - module does not modify PE size for already present volume group
 '''
 
 def parse_vgs(data):
@@ -70,36 +75,63 @@ def parse_vgs(data):
         })
     return vgs
 
+def parse_pvs(data):
+    pvs = []
+    for line in data.splitlines():
+        parts = line.strip().split(';')
+        pvs.append({
+            'name': parts[0],
+            'vg_name': parts[1],
+        })
+    return pvs
+
 def main():
     module = AnsibleModule(
         argument_spec = dict(
             vg=dict(required=True),
             dev=dict(),
+            pesize=dict(),
             state=dict(choices=["absent", "present"], default='present'),
-            force=dict(choices=["yes", "no"], default='no'),
+            force=dict(type='bool', default='no'),
         ),
         supports_check_mode=True,
     )
 
     vg = module.params['vg']
+    state = module.params['state']
+    force = module.boolean(module.params['force'])
+    if module.params['pesize']:
+        pesize = int(module.params['pesize'])
+    else:
+        pesize = 4
+
     if module.params['dev']:
         dev = module.params['dev'].replace(',',' ')
         dev_list = module.params['dev'].split(',')
-    state = module.params['state']
-    force = module.params['force']
-
-    if state=='present' and not dev:
+    elif state == 'present':
         module.fail_json(msg="No dev given.")
 
     if state=='present':
+        ### check given devices
         for test_dev in dev_list:
             if not os.path.exists(test_dev):
                 module.fail_json(msg="No dev %s found."%test_dev)
 
+        ### get pv list
+        rc,current_pvs,err = module.run_command("pvs --noheadings -o pv_name,vg_name --separator ';'")
+        if rc != 0:
+            module.fail_json(msg="Failed executing pvs command.",rc=rc, err=err)
+
+        ### check pv for devices
+        pvs = parse_pvs(current_pvs)
+        used_pvs = filter(lambda pv: pv['name'] in dev_list and pv['vg_name'] and pv['vg_name'] != vg, pvs)
+        if used_pvs:
+            module.fail_json(msg="dev %s is already in %s volume group."%(used_pvs[0]['name'],used_pvs[0]['vg_name']))
+
     rc,current_vgs,err = module.run_command("vgs --noheadings -o vg_name,pv_count,lv_count --separator ';'")
 
     if rc != 0:
-        module.fail_json(msg="Failed creating volume group %s."%vg, rc=rc, err=err)
+        module.fail_json(msg="Failed executing vgs command.",rc=rc, err=err)
 
     changed = False
 
@@ -118,17 +150,24 @@ def main():
             if module.check_mode:
                 changed = True
             else:
-                rc,_,err = module.run_command("vgcreate %s %s"%(vg, dev))
+                ### create PV
+                for current_dev in dev_list:
+                    rc,_,err = module.run_command("pvcreate %s"%current_dev)
+                    if rc == 0:
+                        changed = True
+                    else:
+                        module.fail_json(msg="Creating physical volume '%s' failed"%current_dev, rc=rc, err=err)
+                rc,_,err = module.run_command("vgcreate -s %s %s %s"%(pesize, vg, dev))
                 if rc == 0:
                     changed = True
                 else:
-                    module.fail_json(msg="Creating volume group '%s' failed"%(vg), rc=rc, err=err)
+                    module.fail_json(msg="Creating volume group '%s' failed"%vg, rc=rc, err=err)
     else:
         if state == 'absent':
             if module.check_mode:
                 module.exit_json(changed=True)
             else:
-                if this_vg['lv_count'] == 0 or force == "yes":
+                if this_vg['lv_count'] == 0 or force:
                     ### remove VG
                     rc,_,err = module.run_command("vgremove --force %s"%(vg))
                     if rc == 0:
@@ -138,6 +177,53 @@ def main():
                 else:
                     module.fail_json(msg="Refuse to remove non-empty volume group %s without force=yes"%(vg))
 
+        ### resize VG
+        action = None
+        current_devs = map(lambda x: x['name'], filter(lambda pv: pv['vg_name'] == vg, pvs))
+        devs_to_remove = list(set(current_devs) - set(dev_list))
+        devs_to_add = list(set(dev_list) - set(current_devs))
+        if devs_to_remove and devs_to_add:
+            devs_string = ' '.join([`dev` for dev in devs_to_add])
+            devs_to_remove_string = ' '.join([`dev` for dev in devs_to_remove])
+            action = 'modify'
+        elif devs_to_remove:
+            devs_string = ' '.join([`dev` for dev in devs_to_remove])
+            action = 'reduce'
+        elif devs_to_add:
+            devs_string = ' '.join([`dev` for dev in devs_to_add])
+            action = 'extend'
+
+        if action:
+            if module.check_mode:
+                changed = True
+            else:
+                if action == 'extend' or action == 'modify':
+                    tool = 'vgextend'
+                    ### create PV
+                    for current_dev in devs_to_add:
+                        rc,_,err = module.run_command("pvcreate %s"%current_dev)
+                        if rc == 0:
+                            changed = True
+                        else:
+                            module.fail_json(msg="Creating physical volume '%s' failed"%current_dev, rc=rc, err=err)
+                else:
+                    tool = 'vgreduce --force'
+
+                ### first we add or remove PV
+                rc,_,err = module.run_command("%s %s %s"%(tool, vg, devs_string))
+                if rc == 0:
+                    changed = True
+                else:
+                    module.fail_json(msg="Unable to %s %s by %s."%(action, vg, devs_string),rc=rc,err=err)
+                ### then if we need - remove some PV
+                if action == 'modify':
+                    tool = 'vgreduce --force'
+                    rc,_,err = module.run_command("%s %s %s"%(tool, vg, devs_to_remove_string))
+                    if rc == 0:
+                        changed = True
+                    else:
+                        module.fail_json(msg="Unable to reduce %s by %s."%(vg, devs_to_remove_string),rc=rc,err=err)
+
     module.exit_json(changed=changed)
 
 # this is magic, see lib/ansible/module_common.py