SaltStack: Reverse engineering where a file comes from - debugging

Question

If you look at a host which was set up be SaltStack, then it is sometimes like looking at a binary file with vi.
You have no clue how the config/file was created.
This makes trouble shooting errors hard. Reverse engineering where a file comes from takes too much time.
My goal: Make it easy to find the way from looking at the unix config file on the minion (created by salt) to the source where this configuration came from. Like $Id$ in svn and cvs.
One idea a friend and I had:
The state file.managed should (optionally) add the source of the file.
Example:
My sls file contains this:
file_foo_bar:
file.managed:
- source:
- salt://foo/bar
Then the created file should contain this comment.
# Source: salt://foo/bar
Of course this is not simple, since there are different ways to put comments into configuration files.
Is this feasible? Or is there a better solution to my goal.
Update
Usually I know what I did wrong and can find the root easily. The problem arises if several people work on a state tree.

Answer 1

This is a starting point where you can get the date and time of the modified file when its managed by Salt by using Salt Pillar.
Lets call our variable salt_managed. Create a pillar file like the following:
{% set managed_text = 'Salt managed: File modified on ' + salt.cmd.run('date "+%Y-%m-%d %H:%M:%S"') %}
salt_managed: {{ managed_text | yaml_dquote }}
Then on the minion when you call the pillar you will get the following result:
$ salt-call pillar.get salt_managed
local:
Salt managed: File modified on 2016-10-18 11:12:40
And you can use this by adding it on the top of your config files for example like this:
{{ pillar.get('salt_managed') }}
Update:
I found a work around that might be useful for someone. Lets say we have a multiple states that could modify the same file. How can we know that State X is the responsible for modifying that file ? by doing the following steps:
1- I have created a state like this one:
Create a File:
file.managed:
- name: /path/to/foofile
- source: salt://statedir/barfile
Add file header:
file.prepend:
- name: /path/to/foofile
- text: "This file was managed by using this salt state {{ sls }}"
The contents of barfile is:
This is a new file
2- Call the state from the minion and this will be the result:
$ salt-call state.sls statedir.test
local:
----------
ID: Create a File
Function: file.managed
Name: /path/to/foofile
Result: True
Comment: File /path/to/foofile updated
Started: 07:50:45.254994
Duration: 1034.585 ms
Changes:
----------
diff:
New file
mode:
0644
----------
ID: Add file header
Function: file.prepend
Name: /path/to/foofile
Result: True
Comment: Prepended 1 lines
Started: 07:50:46.289766
Duration: 3.69 ms
Changes:
----------
diff:
---
+++
## -1,1 +1,2 ##
+This file was managed by using this salt state statedir.test
This is a new file
Summary for local
------------
Succeeded: 2 (changed=2)
Failed: 0
------------
Total states run: 2
Currently the content of foofile is:
This file was managed by using this salt state statedir.test
This is a new file