Add Support for --system Option in Sysctl Module

[MubashirUsman]

SUMMARY

Sysctl module does not currently support the --system option, which loads the configuration files from directories in the following order.
/etc/sysctl.d/*.conf
/run/sysctl.d/*.conf
/usr/local/lib/sysctl.d/*.conf
/usr/lib/sysctl.d/*.conf
/lib/sysctl.d/*.conf
/etc/sysctl.conf

I defined SYSCTL_DIRS, list of directories to iterate over if system_wide parameter is set to true. It acts same as sysctl -p <config-file>, and goes over all the paths defined in SYSCTL_DIRS.
Fixes #512

ISSUE TYPE

• Feature Pull Request

COMPONENT NAME

ansible.posix.sysctl

ADDITIONAL INFORMATION

[softwarefactory-project-zuul]

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[MaKaNu]

What is the status of this PR?

I am also at that point.

[saito-hideki]

Thank you for the PR! :)
As far as I know, sysctlmodule adds or removes the sysctl parameters specified by the name parameter (which is required) to/from the configuration file specified by sysctl_file, and if the reload option is set to true, it will reload the file.

The system_wide option in this PR reloads not only the modified file but other files as well. Is this functionality truly necessary?
If the intention is simply to reload all configuration files, similar to sysctl --system, I believe it would be necessary to change the name parameter from required to optional.

[MaKaNu]

The system_wide option in this PR reloads not only the modified file but other files as well. Is this functionality truly necessary?

From the ubuntu man page:

--system
Load settings from all system configuration files. Files are read from directories
in the following list in given order from top to bottom. Once a file of a given
filename is loaded, any file of the same name in subsequent directories is ignored.
/run/sysctl.d/.conf
/etc/sysctl.d/.conf
/usr/local/lib/sysctl.d/.conf
/usr/lib/sysctl.d/.conf
/lib/sysctl.d/*.conf
/etc/sysctl.conf

[saito-hideki]

@MubashirUsman
Thank you for the update :)

From the ubuntu man page

As mentioned in the man page you pointed out, --system option changes the basic behavior of the sysctl module, which defines sysctl parameters in a specific file and reflects the values by reloading only that file. I was concerned about that point.
So, I would like to know the specific use cases that require this function.
The typical use case would be to set several parameters in multiple files and then reload all the files with sysctl --system to apply the changes all at once.
However, sysct module applies one parameter to one file per task. Therefore I simply thought that the typical bulk application mentioned above might be better handled using the shell module or similar. I'd like to hear your thoughts on this.