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

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.
+  - description: Create a volume group on top of /dev/sda1 with physical extent size = 32MB.
-    code: lvg vg=vg.services dev=/dev/sda1
+    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']
+    elif state == 'present':
-    force = module.params['force']
-
-    if state=='present' and not dev:
         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 volume group '%s' failed"%(vg), rc=rc, err=err)
+                        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)
     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