file.line does not work with "ensure" mode when file is empty or line is absent

[andrewm41]

Hello, as I can understand I have no chance to make sure that some line is in file with one task. So this is some kind of feature request.

file.line module is rather useless with mode ensure, it requires before/after. But I don't know the content of file and it may be absent or empty. I don't understand how you intend to use option create in mode ensure at all.

Please consider ansible module lineinfile for reference.

[arizvisa]

Agreed actually. Just encountered this issue.

I actually believe this to be in the salt.modules.file module and is due to the usage of the results returned from the _regex_to_static functions. In my experience, saltstack has historically had problem like this in a number of places.

This issue is that the _regex_to_static is actually used to filter the file's body with the following code from salt.modules.file.py:

    after = _regex_to_static(body, after)
    before = _regex_to_static(body, before)
    match = _regex_to_static(body, match)

These functions actually return two values, None for an error and a list ([]) for the contents of the file. Later for the ensure cases, these types are being checked as booleans which means an empty file will always be treated as False and so absolutely none of these cases are hit which gives you a misleading exception in your logs.

        if before and after:
...
        elif before and not after:
...
        elif not before and after:
...
        else:
            raise CommandExecutionError("Wrong conditions? "
                                        "Unable to ensure line without knowing "
                                        "where to put it before and/or after.")

If you're checking for non-existence of a parameter, you need to explicitly check it against the default value of the parameter, None, instead of checking for falseness. Because this means that an empty file will never be able to have file.line used in ensure mode.

[arizvisa]

@andrewm41, do you mind renaming the topic of this issue to something like:
file.line does not work with "ensure" mode when file is empty or line is absent.

Also in your case, if you don't know the contents of the file, you can actually specify an "anything" regex for the before or after keywords with ".*" as your regex. That should match against anything.

However, if your file is empty you'll still hit that "Wrong conditions?" case that I mentioned.

[arizvisa]

In case my previous comment wasn't clear, you should be able to do the following with one rule:

ensure line is in file:
    file.line:
        - name: /etc/adobe/mms.cfg
        - mode: ensure
        - content: "AutoUpdateDisable=1"
        - after: ".*"

This means that after any line that matches the ".*" regex, add the AutoUpdateDisable=1 line. But again, it doesn't work on an empty file because of the prior mentioned bug which you probably encountered.

[andrewm41]

But again, it doesn't work on an empty file because of the prior mentioned bug which you probably encountered.

Yes, exactly the case I meant.

[arizvisa]

much appreciated, andrew.

hopefully that's enough for other users to find this issue, and then hopefully the maintainers get around to going through these.

[xeacott]

Let me ping @waynew on this... I recall him being active in this module not too long ago and may be able to address this much faster than myself!

[xeacott]

Hey @andrewm41 can you run a salt --versions-report and paste that in here? Last I remember there was some work being done in the module and we can see if the issue still persists in your issue vs latest/master.

[andrewm41]

           Salt: 2019.2.0
 
Dependency Versions:
           cffi: 1.11.5
       cherrypy: Not Installed
       dateutil: Not Installed
      docker-py: Not Installed
          gitdb: Not Installed
      gitpython: Not Installed
          ioflo: Not Installed
         Jinja2: 2.10
        libgit2: Not Installed
        libnacl: Not Installed
       M2Crypto: Not Installed
           Mako: Not Installed
   msgpack-pure: Not Installed
 msgpack-python: 0.4.8
   mysql-python: Not Installed
      pycparser: 2.18
       pycrypto: 2.6.1
   pycryptodome: Not Installed
         pygit2: Not Installed
         Python: 2.7.5 (default, Aug  4 2017, 00:39:18)
   python-gnupg: Not Installed
         PyYAML: 3.12
          PyZMQ: 15.3.0
           RAET: Not Installed
          smmap: Not Installed
        timelib: Not Installed
        Tornado: 4.2.1
            ZMQ: 4.1.4
 
System Versions:
           dist: centos 7.4.1708 Core
         locale: UTF-8
        machine: x86_64
        release: 3.10.0-693.17.1.el7.x86_64
         system: Linux
        version: CentOS Linux 7.4.1708 Core

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