| Dir : /proc/self/root/opt/saltstack/salt/lib/python3.10/site-packages/salt/states/ |
| Server: Linux ngx353.inmotionhosting.com 4.18.0-553.22.1.lve.1.el8.x86_64 #1 SMP Tue Oct 8 15:52:54 UTC 2024 x86_64 IP: 209.182.202.254 |
| Dir : //proc/self/root/opt/saltstack/salt/lib/python3.10/site-packages/salt/states/snapper.py |
"""
Managing implicit state and baselines using snapshots
=====================================================
.. versionadded:: 2016.11.0
Salt can manage state against explicitly defined state, for example
if your minion state is defined by:
.. code-block:: yaml
/etc/config_file:
file.managed:
- source: salt://configs/myconfig
If someone modifies this file, the next application of the highstate will
allow the admin to correct this deviation and the file will be corrected.
Now, what happens if somebody creates a file ``/etc/new_config_file`` and
deletes ``/etc/important_config_file``? Unless you have a explicit rule, this
change will go unnoticed.
The snapper state module allows you to manage state implicitly, in addition
to explicit rules, in order to define a baseline and iterate with explicit
rules as they show that they work in production.
The workflow is: once you have a working and audited system, you would create
your baseline snapshot (eg. with ``salt tgt snapper.create_snapshot``) and
define in your state this baseline using the identifier of the snapshot
(in this case: 20):
.. code-block:: yaml
my_baseline:
snapper.baseline_snapshot:
- number: 20
- include_diff: False
- ignore:
- /var/log
- /var/cache
Baseline snapshots can be also referenced by tag. Most recent baseline snapshot
is used in case of multiple snapshots with the same tag:
my_baseline_external_storage:
snapper.baseline_snapshot:
- tag: my_custom_baseline_tag
- config: external
- ignore:
- /mnt/tmp_files/
If you have this state, and you haven't done changes to the system since the
snapshot, and you add a user, the state will show you the changes (including
full diffs) to ``/etc/passwd``, ``/etc/shadow``, etc if you call it
with ``test=True`` and will undo all changes if you call it without.
This allows you to add more explicit state knowing that you are starting from a
very well defined state, and that you can audit any change that is not part
of your explicit configuration.
So after you made this your state, you decided to introduce a change in your
configuration:
.. code-block:: yaml
my_baseline:
snapper.baseline_snapshot:
- number: 20
- ignore:
- /var/log
- /var/cache
hosts_entry:
file.blockreplace:
- name: /etc/hosts
- content: 'First line of content'
- append_if_not_found: True
The change in ``/etc/hosts`` will be done after any other change that deviates
from the specified snapshot are reverted. This could be for example,
modifications to the ``/etc/passwd`` file or changes in the ``/etc/hosts``
that could render your the ``hosts_entry`` rule void or dangerous.
Once you take a new snapshot and you update the baseline snapshot number to
include the change in ``/etc/hosts`` the ``hosts_entry`` rule will basically
do nothing. You are free to leave it there for documentation, to ensure that
the change is made in case the snapshot is wrong, but if you remove anything
that comes after the ``snapper.baseline_snapshot`` as it will have no effect;
by the moment the state is evaluated, the baseline state was already applied
and include this change.
.. warning::
Make sure you specify the baseline state before other rules, otherwise
the baseline state will revert all changes if they are not present in
the snapshot.
.. warning::
Do not specify more than one baseline rule as only the last one will
affect the result.
:codeauthor: Duncan Mac-Vicar P. <dmacvicar@suse.de>
:codeauthor: Pablo Suárez Hernández <psuarezhernandez@suse.de>
:maturity: new
:platform: Linux
"""
import os
def __virtual__():
"""
Only load if the snapper module is available in __salt__
"""
if "snapper.diff" in __salt__:
return "snapper"
return (False, "snapper module could not be loaded")
def _get_baseline_from_tag(config, tag):
"""
Returns the last created baseline snapshot marked with `tag`
"""
last_snapshot = None
for snapshot in __salt__["snapper.list_snapshots"](config):
if tag == snapshot["userdata"].get("baseline_tag"):
if not last_snapshot or last_snapshot["timestamp"] < snapshot["timestamp"]:
last_snapshot = snapshot
return last_snapshot
def baseline_snapshot(
name, number=None, tag=None, include_diff=True, config="root", ignore=None
):
"""
Enforces that no file is modified comparing against a previously
defined snapshot identified by number.
number
Number of selected baseline snapshot.
tag
Tag of the selected baseline snapshot. Most recent baseline baseline
snapshot is used in case of multiple snapshots with the same tag.
(`tag` and `number` cannot be used at the same time)
include_diff
Include a diff in the response (Default: True)
config
Snapper config name (Default: root)
ignore
List of files to ignore. (Default: None)
"""
if not ignore:
ignore = []
ret = {"changes": {}, "comment": "", "name": name, "result": True}
if number is None and tag is None:
ret.update(
{"result": False, "comment": "Snapshot tag or number must be specified"}
)
return ret
if number and tag:
ret.update(
{
"result": False,
"comment": "Cannot use snapshot tag and number at the same time",
}
)
return ret
if tag:
snapshot = _get_baseline_from_tag(config, tag)
if not snapshot:
ret.update({"result": False, "comment": f'Baseline tag "{tag}" not found'})
return ret
number = snapshot["id"]
status = __salt__["snapper.status"](config, num_pre=0, num_post=number)
for target in ignore:
if os.path.isfile(target):
status.pop(target, None)
elif os.path.isdir(target):
for target_file in [
target_file
for target_file in status.keys()
if target_file.startswith(target)
]:
status.pop(target_file, None)
for file in status:
# Only include diff for modified files
if "modified" in status[file]["status"] and include_diff:
status[file].pop("status")
status[file].update(
__salt__["snapper.diff"](
config, num_pre=0, num_post=number, filename=file
).get(file, {})
)
if __opts__["test"] and status:
ret["changes"] = status
ret["comment"] = "{} files changes are set to be undone".format(
len(status.keys())
)
ret["result"] = None
elif __opts__["test"] and not status:
ret["changes"] = {}
ret["comment"] = "Nothing to be done"
ret["result"] = True
elif not __opts__["test"] and status:
undo = __salt__["snapper.undo"](
config, num_pre=number, num_post=0, files=status.keys()
)
ret["changes"]["sumary"] = undo
ret["changes"]["files"] = status
ret["result"] = True
else:
ret["comment"] = "No changes were done"
ret["result"] = True
return ret