Merge pull request #52699 from aplanas/fix_brtfs

btrfs: Add properties state

doc/ref/states/all/index.rst

@@ -66,6 +66,7 @@ state modules
     boto_sqs
     boto_vpc
     bower
+    btrfs
     cabal
     ceph
     chef

doc/ref/states/all/salt.states.btrfs.rst

@@ -0,0 +1,6 @@
+=================
+salt.states.btrfs
+=================
+
+.. automodule:: salt.states.btrfs
+    :members:

salt/states/btrfs.py

@@ -0,0 +1,377 @@
+# -*- coding: utf-8 -*-
+
+"""
+:maintainer:    Alberto Planas <[email protected]>
+:maturity:      new
+:depends:       None
+:platform:      Linux
+"""
+from __future__ import absolute_import, print_function, unicode_literals
+
+import functools
+import logging
+import os.path
+import tempfile
+import traceback
+
+from salt.exceptions import CommandExecutionError
+
+log = logging.getLogger(__name__)
+
+__virtualname__ = "btrfs"
+
+
+def _mount(device, use_default):
+    """
+    Mount the device in a temporary place.
+    """
+    opts = "defaults" if use_default else "subvol=/"
+    dest = tempfile.mkdtemp()
+    res = __states__["mount.mounted"](
+        dest, device=device, fstype="btrfs", opts=opts, persist=False
+    )
+    if not res["result"]:
+        log.error("Cannot mount device %s in %s", device, dest)
+        _umount(dest)
+        return None
+    return dest
+
+
+def _umount(path):
+    """
+    Umount and clean the temporary place.
+    """
+    __states__["mount.unmounted"](path)
+    __utils__["files.rm_rf"](path)
+
+
+def _is_default(path, dest, name):
+    """
+    Check if the subvolume is the current default.
+    """
+    subvol_id = __salt__["btrfs.subvolume_show"](path)[name]["subvolume id"]
+    def_id = __salt__["btrfs.subvolume_get_default"](dest)["id"]
+    return subvol_id == def_id
+
+
+def _set_default(path, dest, name):
+    """
+    Set the subvolume as the current default.
+    """
+    subvol_id = __salt__["btrfs.subvolume_show"](path)[name]["subvolume id"]
+    return __salt__["btrfs.subvolume_set_default"](subvol_id, dest)
+
+
+def _is_cow(path):
+    """
+    Check if the subvolume is copy on write
+    """
+    dirname = os.path.dirname(path)
+    return "C" not in __salt__["file.lsattr"](dirname)[path]
+
+
+def _unset_cow(path):
+    """
+    Disable the copy on write in a subvolume
+    """
+    return __salt__["file.chattr"](path, operator="add", attributes="C")
+
+
+def __mount_device(action):
+    """
+    Small decorator to makes sure that the mount and umount happends in
+    a transactional way.
+    """
+
+    @functools.wraps(action)
+    def wrapper(*args, **kwargs):
+        name = kwargs["name"]
+        device = kwargs["device"]
+        use_default = kwargs.get("use_default", False)
+
+        ret = {
+            "name": name,
+            "result": False,
+            "changes": {},
+            "comment": ["Some error happends during the operation."],
+        }
+        try:
+            if device:
+                dest = _mount(device, use_default)
+                if not dest:
+                    msg = "Device {} cannot be mounted".format(device)
+                    ret["comment"].append(msg)
+                kwargs["__dest"] = dest
+            ret = action(*args, **kwargs)
+        except Exception as e:  # pylint: disable=broad-except
+            log.error("""Traceback: {}""".format(traceback.format_exc()))
+            ret["comment"].append(e)
+        finally:
+            if device:
+                _umount(dest)
+        return ret
+
+    return wrapper
+
+
+@__mount_device
+def subvolume_created(
+    name,
+    device,
+    qgroupids=None,
+    set_default=False,
+    copy_on_write=True,
+    force_set_default=True,
+    __dest=None,
+):
+    """
+    Makes sure that a btrfs subvolume is present.
+
+    name
+        Name of the subvolume to add
+
+    device
+        Device where to create the subvolume
+
+    qgroupids
+         Add the newly created subcolume to a qgroup. This parameter
+         is a list
+
+    set_default
+        If True, this new subvolume will be set as default when
+        mounted, unless subvol option in mount is used
+
+    copy_on_write
+        If false, set the subvolume with chattr +C
+
+    force_set_default
+        If false and the subvolume is already present, it will not
+        force it as default if ``set_default`` is True
+
+    """
+    ret = {
+        "name": name,
+        "result": False,
+        "changes": {},
+        "comment": [],
+    }
+    path = os.path.join(__dest, name)
+
+    exists = __salt__["btrfs.subvolume_exists"](path)
+    if exists:
+        ret["comment"].append("Subvolume {} already present".format(name))
+
+    # Resolve first the test case. The check is not complete, but at
+    # least we will report if a subvolume needs to be created. Can
+    # happend that the subvolume is there, but we also need to set it
+    # as default, or persist in fstab.
+    if __opts__["test"]:
+        ret["result"] = None
+        if not exists:
+            ret["changes"][name] = "Subvolume {} will be created".format(name)
+        return ret
+
+    if not exists:
+        # Create the directories where the subvolume lives
+        _path = os.path.dirname(path)
+        res = __states__["file.directory"](_path, makedirs=True)
+        if not res["result"]:
+            ret["comment"].append("Error creating {} directory".format(_path))
+            return ret
+
+        try:
+            __salt__["btrfs.subvolume_create"](name, dest=__dest, qgroupids=qgroupids)
+        except CommandExecutionError:
+            ret["comment"].append("Error creating subvolume {}".format(name))
+            return ret
+
+        ret["changes"][name] = "Created subvolume {}".format(name)
+
+    # If the volume was already present, we can opt-out the check for
+    # default subvolume.
+    if (
+        (not exists or (exists and force_set_default))
+        and set_default
+        and not _is_default(path, __dest, name)
+    ):
+        ret["changes"][name + "_default"] = _set_default(path, __dest, name)
+
+    if not copy_on_write and _is_cow(path):
+        ret["changes"][name + "_no_cow"] = _unset_cow(path)
+
+    ret["result"] = True
+    return ret
+
+
+@__mount_device
+def subvolume_deleted(name, device, commit=False, __dest=None):
+    """
+    Makes sure that a btrfs subvolume is removed.
+
+    name
+        Name of the subvolume to remove
+
+    device
+        Device where to remove the subvolume
+
+    commit
+        Wait until the transaction is over
+
+    """
+    ret = {
+        "name": name,
+        "result": False,
+        "changes": {},
+        "comment": [],
+    }
+
+    path = os.path.join(__dest, name)
+
+    exists = __salt__["btrfs.subvolume_exists"](path)
+    if not exists:
+        ret["comment"].append("Subvolume {} already missing".format(name))
+
+    if __opts__["test"]:
+        ret["result"] = None
+        if exists:
+            ret["changes"][name] = "Subvolume {} will be removed".format(name)
+        return ret
+
+    # If commit is set, we wait until all is over
+    commit = "after" if commit else None
+
+    if not exists:
+        try:
+            __salt__["btrfs.subvolume_delete"](path, commit=commit)
+        except CommandExecutionError:
+            ret["comment"].append("Error removing subvolume {}".format(name))
+            return ret
+
+        ret["changes"][name] = "Removed subvolume {}".format(name)
+
+    ret["result"] = True
+    return ret
+
+
+def _diff_properties(expected, current):
+    """Calculate the difference between the current and the expected
+    properties
+
+    * 'expected' is expressed in a dictionary like: {'property': value}
+
+    * 'current' contains the same format retuned by 'btrfs.properties'
+
+    If the property is not available, will throw an exception.
+
+    """
+    difference = {}
+    for _property, value in expected.items():
+        current_value = current[_property]["value"]
+        if value is False and current_value == "N/A":
+            needs_update = False
+        elif value != current_value:
+            needs_update = True
+        else:
+            needs_update = False
+        if needs_update:
+            difference[_property] = value
+    return difference
+
+
+@__mount_device
+def properties(name, device, use_default=False, __dest=None, **properties):
+    """
+    Makes sure that a list of properties are set in a subvolume, file
+    or device.
+
+    name
+        Name of the object to change
+
+    device
+        Device where the object lives, if None, the device will be in
+        name
+
+    use_default
+        If True, this subvolume will be resolved to the default
+        subvolume assigned during the create operation
+
+    properties
+        Dictionary of properties
+
+    Valid properties are 'ro', 'label' or 'compression'. Check the
+    documentation to see where those properties are valid for each
+    object.
+
+    """
+    ret = {
+        "name": name,
+        "result": False,
+        "changes": {},
+        "comment": [],
+    }
+
+    # 'name' will have always the name of the object that we want to
+    # change, but if the object is a device, we do not repeat it again
+    # in 'device'. This makes device sometimes optional.
+    if device:
+        if os.path.isabs(name):
+            path = os.path.join(__dest, os.path.relpath(name, os.path.sep))
+        else:
+            path = os.path.join(__dest, name)
+    else:
+        path = name
+
+    if not os.path.exists(path):
+        ret["comment"].append("Object {} not found".format(name))
+        return ret
+
+    # Convert the booleans to lowercase
+    properties = {
+        k: v if type(v) is not bool else str(v).lower() for k, v in properties.items()
+    }
+
+    current_properties = {}
+    try:
+        current_properties = __salt__["btrfs.properties"](path)
+    except CommandExecutionError as e:
+        ret["comment"].append("Error reading properties from {}".format(name))
+        ret["comment"].append("Current error {}".format(e))
+        return ret
+
+    try:
+        properties_to_set = _diff_properties(properties, current_properties)
+    except KeyError:
+        ret["comment"].append("Some property not found in {}".format(name))
+        return ret
+
+    if __opts__["test"]:
+        ret["result"] = None
+        if properties_to_set:
+            ret["changes"] = properties_to_set
+        else:
+            msg = "No properties will be changed in {}".format(name)
+            ret["comment"].append(msg)
+        return ret
+
+    if properties_to_set:
+        _properties = ",".join(
+            "{}={}".format(k, v) for k, v in properties_to_set.items()
+        )
+        __salt__["btrfs.properties"](path, set=_properties)
+
+        current_properties = __salt__["btrfs.properties"](path)
+        properties_failed = _diff_properties(properties, current_properties)
+        if properties_failed:
+            msg = "Properties {} failed to be changed in {}".format(
+                properties_failed, name
+            )
+            ret["comment"].append(msg)
+            return ret
+
+        ret["comment"].append("Properties changed in {}".format(name))
+        ret["changes"] = properties_to_set
+    else:
+        ret["comment"].append("Properties not changed in {}".format(name))
+
+    ret["result"] = True
+    return ret