Merge pull request #43 from dwlehman/non-destructive

Add flag to prevent implicit removal of existing device/fs.

Author: dwlehman

README.md

@@ -73,6 +73,9 @@ The `mount_point` specifies the directory on which the file system will be mount
 ##### `mount_options`
 The `mount_options` specifies custom mount options as a string, e.g.: 'ro'.
 
+#### `storage_safe_mode`
+When true (the default), an error will occur instead of automatically removing existing devices and/or formatting.
+
 
 Example Playbook
 ----------------

defaults/main.yml

@@ -3,6 +3,7 @@
 storage_provider: "blivet"
 storage_use_partitions: null
 storage_disklabel_type: null  # leave unset to allow the role to select an appropriate label type
+storage_safe_mode: true  # fail instead of implicitly/automatically removing devices or formatting
 
 storage_pool_defaults:
   state: "present"

library/blivet.py

@@ -31,6 +31,10 @@
     disklabel_type:
         description:
             - disklabel type string (eg: 'gpt') to use, overriding the built-in logic in blivet
+    safe_mode:
+        description:
+            - boolean indicating that we should fail rather than implicitly/automatically
+              removing devices or formatting
 
 author:
     - David Lehman (dlehman@redhat.com)
@@ -116,6 +120,8 @@
 
 use_partitions = None  # create partitions on pool backing device disks?
 disklabel_type = None  # user-specified disklabel type
+safe_mode = None       # do not remove any existing devices or formatting
+packages_only = None   # only set things up enough to get a list of required packages
 
 
 class BlivetAnsibleError(Exception):
@@ -163,7 +169,6 @@ def _get_format(self):
                          label=self._volume['fs_label'],
                          options=self._volume['fs_create_options'])
         if not fmt.supported or not fmt.formattable:
-            # FAIL: fs type tools are not available
             raise BlivetAnsibleError("required tools for file system '%s' are missing" % self._volume['fs_type'])
 
         return fmt
@@ -189,32 +194,35 @@ def _resize(self):
         try:
             size = Size(self._volume['size'])
         except Exception:
-            # FAIL: invalid size specification
             raise BlivetAnsibleError("invalid size specification for volume '%s': '%s'" % (self._volume['name'], self._volume['size']))
 
         if size and self._device.resizable and self._device.size != size:
             if self._device.format.resizable:
                 self._device.format.update_size_info()
 
             if not self._device.min_size <= size <= self._device.max_size:
-                # FAIL: resize to specified size not possible
                 raise BlivetAnsibleError("volume '%s' cannot be resized to '%s'" % (self._volume['name'], size))
 
             try:
                 self._blivet.resize_device(self._device, size)
             except ValueError as e:
-                # FAIL: resize not possible
                 raise BlivetAnsibleError("volume '%s' cannot be resized from %s to %s: %s" % (self._device.name,
                                                                                               self._device.size,
                                                                                               size, str(e)))
 
     def _reformat(self):
         """ Schedule actions as needed to ensure the volume is formatted as specified. """
+        global packages_only
+
         fmt = self._get_format()
         if self._device.format.type == fmt.type:
             return
 
-        if self._device.format.status:
+        if safe_mode and (self._device.format.type is not None or self._device.format.name != get_format(None).name) and \
+           not packages_only:
+            raise BlivetAnsibleError("cannot remove existing formatting on volume '%s' in safe mode" % self._volume['name'])
+
+        if self._device.format.status and not packages_only:
             self._device.format.teardown()
         self._blivet.format_device(self._device, fmt)
 
@@ -255,6 +263,17 @@ def _get_device_id(self):
     def _type_check(self):
         return self._device.is_disk
 
+    def _look_up_device(self):
+        super(BlivetDiskVolume, self)._look_up_device()
+        if not self._get_device_id():
+            raise BlivetAnsibleError("no disks specified for volume '%s'" % self._volume['name'])
+        elif not isinstance(self._volume['disks'], list):
+            raise BlivetAnsibleError("volume disks must be specified as a list")
+
+        if self._device is None:
+            raise BlivetAnsibleError("unable to resolve disk specified for volume '%s' (%s)" % (self._volume['name'], self._volume['disks']))
+
+
 
 class BlivetPartitionVolume(BlivetVolume):
     def _type_check(self):
@@ -273,21 +292,18 @@ def _create(self):
             parent = self._blivet.devicetree.resolve_device(self._volume['pool'])
 
         if parent is None:
-            # FAIL: failed to find pool
             raise BlivetAnsibleError("failed to find pool '%s' for volume '%s'" % (self._blivet_pool['name'], self._volume['name']))
 
         size = Size("256 MiB")
         try:
             device = self._blivet.new_partition(parents=[parent], size=size, grow=True, fmt=self._get_format())
         except Exception:
-            # FAIL: failed to instantiate volume device
             raise BlivetAnsibleError("failed set up volume '%s'" % self._volume['name'])
 
         self._blivet.create_device(device)
         try:
             do_partitioning(self._blivet)
         except Exception:
-            # FAIL: partition allocation failed: not enough space?
             raise BlivetAnsibleError("partition allocation failed for volume '%s'" % self._volume['name'])
 
         self._device = device
@@ -303,18 +319,15 @@ def _create(self):
 
         parent = self._blivet_pool._device
         if parent is None:
-            # FAIL: failed to find pool
             raise BlivetAnsibleError("failed to find pool '%s' for volume '%s'" % (self._blivet_pool['name'], self._volume['name']))
 
         try:
             size = Size(self._volume['size'])
         except Exception:
-            # FAIL: invalid size specification
             raise BlivetAnsibleError("invalid size '%s' specified for volume '%s'" % (self._volume['size'], self._volume['name']))
 
         fmt = self._get_format()
         if size > parent.free_space:
-            # FAIL: volume size greater than pool free space
             raise BlivetAnsibleError("specified size for volume '%s' exceeds available space in pool '%s' (%s)" % (size,
                                                                                                                    parent.name,
                                                                                                                    parent.free_space))
@@ -323,7 +336,6 @@ def _create(self):
             device = self._blivet.new_lv(name=self._volume['name'],
                                          parents=[parent], size=size, fmt=fmt)
         except Exception:
-            # FAIL: failed to create volume
             raise BlivetAnsibleError("failed to set up volume '%s'" % self._volume['name'])
 
         self._blivet.create_device(device)
@@ -391,8 +403,7 @@ def _type_check(self):  # pylint: disable=no-self-use
     def _look_up_disks(self):
         """ Look up the pool's disks in blivet's device tree. """
         if not self._pool['disks']:
-            # FAIL: no disks specified for pool
-            raise BlivetAnsibleError("no disks specified for pool '%s'" % self._pool['name'])  # sure about this one?
+            raise BlivetAnsibleError("no disks specified for pool '%s'" % self._pool['name'])
         elif not isinstance(self._pool['disks'], list):
             raise BlivetAnsibleError("pool disks must be specified as a list")
 
@@ -403,7 +414,6 @@ def _look_up_disks(self):
                 disks.append(device)
 
         if self._pool['disks'] and not disks:
-            # FAIL: failed to find any disks
             raise BlivetAnsibleError("unable to resolve any disks specified for pool '%s' (%s)" % (self._pool['name'], self._pool['disks']))
 
         self._disks = disks
@@ -428,8 +438,11 @@ def _create_members(self):
         """ Schedule actions as needed to ensure pool member devices exist. """
         members = list()
         for disk in self._disks:
-            if not disk.isleaf:
-                self._blivet.devicetree.recursive_remove(disk)
+            if not disk.isleaf or disk.format.type is not None:
+                if safe_mode and not packages_only:
+                    raise BlivetAnsibleError("cannot remove existing formatting and/or devices on disk '%s' (pool '%s') in safe mode" % (disk.name, self._pool['name']))
+                else:
+                    self._blivet.devicetree.recursive_remove(disk)
 
             if use_partitions:
                 label = get_format("disklabel", device=disk.path)
@@ -446,7 +459,6 @@ def _create_members(self):
             try:
                 do_partitioning(self._blivet)
             except Exception:
-                # FAIL: problem allocating partitions for pool backing devices
                 raise BlivetAnsibleError("failed to allocation partitions for pool '%s'" % self._pool['name'])
 
         return members
@@ -490,7 +502,11 @@ def _look_up_device(self):
     def _create(self):
         if self._device.format.type != "disklabel" or \
            self._device.format.label_type != disklabel_type:
-            self._blivet.devicetree.recursive_remove(self._device, remove_device=False)
+            if safe_mode and not packages_only:
+                raise BlivetAnsibleError("cannot remove existing formatting and/or devices on disk '%s' "
+                                         "(pool '%s') in safe mode" % (self._device.name, self._pool['name']))
+            else:
+                self._blivet.devicetree.recursive_remove(self._device, remove_device=False)
 
             label = get_format("disklabel", device=self._device.path, label_type=disklabel_type)
             self._blivet.format_device(self._device, label)
@@ -503,7 +519,6 @@ def _type_check(self):
     def _get_format(self):
         fmt = get_format("lvmpv")
         if not fmt.supported or not fmt.formattable:
-            # FAIL: lvm tools are not available
             raise BlivetAnsibleError("required tools for managing LVM are missing")
 
         return fmt
@@ -516,15 +531,14 @@ def _create(self):
         try:
             pool_device = self._blivet.new_vg(name=self._pool['name'], parents=members)
         except Exception:
-            # FAIL: failed to instantiate pool device
             raise BlivetAnsibleError("failed to set up pool '%s'" % self._pool['name'])
 
         self._blivet.create_device(pool_device)
         self._device = pool_device
 
 
 _BLIVET_POOL_TYPES = {
-    "disk": BlivetPartitionPool,
+    "partition": BlivetPartitionPool,
     "lvm": BlivetLVMPool
 }
 
@@ -660,6 +674,7 @@ def run_module():
         volumes=dict(type='list'),
         packages_only=dict(type='bool', required=False, default=False),
         disklabel_type=dict(type='str', required=False, default=None),
+        safe_mode=dict(type='bool', required=False, default=True),
         use_partitions=dict(type='bool', required=False, default=True))
 
     # seed the result dict in the object
@@ -692,6 +707,12 @@ def run_module():
     global use_partitions
     use_partitions = module.params['use_partitions']
 
+    global safe_mode
+    safe_mode = module.params['safe_mode']
+
+    global packages_only
+    packages_only = module.params['packages_only']
+
     b = Blivet()
     b.reset()
     fstab = FSTab(b)

tasks/main-blivet.yml

@@ -38,7 +38,7 @@
     _storage_vols_no_defaults: "{{ _storage_vols_no_defaults|default([]) }} + [{{ item.1 }}]"
     _storage_vol_defaults: "{{ _storage_vol_defaults|default([]) }} + [{{ storage_volume_defaults }}]"
     _storage_vol_pools: "{{ _storage_vol_pools|default([]) }} + ['{{ item.0.name }}']"
-  loop: "{{ _storage_pools|subelements('volumes') }}"
+  loop: "{{ _storage_pools|subelements('volumes', skip_missing=true) }}"
   when: storage_pools is defined
 
 - name: Apply defaults to pools and volumes [3/6]
@@ -105,6 +105,7 @@
     volumes: "{{ _storage_volumes }}"
     use_partitions: "{{ storage_use_partitions }}"
     disklabel_type: "{{ storage_disklabel_type }}"
+    safe_mode: "{{ storage_safe_mode }}"
   register: blivet_output
 
 - debug:

tests/tests_change_disk_fs.yml

@@ -2,6 +2,7 @@
 - hosts: all
   become: true
   vars:
+    storage_safe_mode: false
     mount_location: '/opt/test'
     volume_size: '5g'
     fs_type_after: "{{ 'ext3' if (ansible_distribution == 'RedHat' and ansible_distribution_major_version == '6') else 'ext4' }}"

tests/tests_change_fs.yml

@@ -2,6 +2,7 @@
 - hosts: all
   become: true
   vars:
+    storage_safe_mode: false
     mount_location: '/opt/test1'
     volume_size: '5g'
     fs_after: "{{ (ansible_distribution == 'RedHat' and ansible_distribution_major_version == '6') | ternary('ext4', 'xfs') }}"

tests/tests_change_fs_use_partitions.yml

@@ -2,6 +2,7 @@
 - hosts: all
   become: true
   vars:
+    storage_safe_mode: false
     storage_use_partitions: true
     mount_location: '/opt/test1'
     volume_size: '5g'

tests/tests_create_disk_then_remove.yml

@@ -2,6 +2,7 @@
 - hosts: all
   become: true
   vars:
+    storage_safe_mode: false
     mount_location: '/opt/test1'
 
   tasks:

tests/tests_create_lvm_pool_then_remove.yml

@@ -2,6 +2,7 @@
 - hosts: all
   become: true
   vars:
+    storage_safe_mode: false
     mount_location1: '/opt/test1'
     mount_location2: '/opt/test2'
     volume_group_size: '10g'

tests/tests_create_partition_volume_then_remove.yml

@@ -2,6 +2,7 @@
 - hosts: all
   become: true
   vars:
+    storage_safe_mode: false
     mount_location: '/opt/test1'
 
   tasks:
@@ -18,7 +19,7 @@
       vars:
         storage_pools:
           - name: "{{ unused_disks[0] }}"
-            type: disk
+            type: partition
             disks: "{{ unused_disks }}"
             volumes:
               - name: test1
@@ -33,7 +34,7 @@
       vars:
         storage_pools:
           - name: "{{ unused_disks[0] }}"
-            type: disk
+            type: partition
             disks: "{{ unused_disks }}"
             volumes:
               - name: test1
@@ -48,7 +49,7 @@
       vars:
         storage_pools:
           - name:  "{{ unused_disks[0] }}"
-            type: disk
+            type: partition
             disks: "{{ unused_disks }}"
             state: absent
             volumes:
@@ -65,7 +66,7 @@
       vars:
         storage_pools:
           - name:  "{{ unused_disks[0] }}"
-            type: disk
+            type: partition
             disks: "{{ unused_disks }}"
             state: absent
             volumes: