Find init in PATH when use Linux

[RMTT]

Describe your changes

Find init from system PATH instead of hardcode the /sbin/init in GetInitType when use Linux.

Some Linux distros have no /sbin, such as NixOS , but the init can be found in PATH in most cases.
But If there is no init in PATH, user just need change PATH before start netclient.

Checklist before requesting a review

• My changes affect only 10 files or less.
• I have performed a self-review of my code and tested it.
• If it is a new feature, I have added thorough tests, my code is <= 1450 lines.
• If it is a bugfix, my code is <= 200 lines.
• My functions are <= 80 lines.
• I have had my code reviewed by a peer.
• My unit tests pass locally.
• Netclient & Netmaker are awesome.

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All committers have signed the CLA.

[yabinma]

@RMTT , Thank you for opening the PR. It's good for checking init on system without /sbin folder.

/sbin is not the only place used in the code logic. netclient executable file is also installed under /sbin. I am not sure if you are interested in making the change for installation directory. Otherwise the install will be still failed even the init check passed.

[RMTT]

@RMTT , Thank you for opening the PR. It's good for checking init on system without /sbin folder.

/sbin is not the only place used in the code logic. netclient executable file is also installed under /sbin. I am not sure if you are interested in making the change for installation directory. Otherwise the install will be still failed even the init check passed.

Sorry, i don't understand your proposal. This pr only modified the logic to find init, it doesn't affect the installation behavior of netclient.

[yabinma]

@RMTT , Thank you for opening the PR. It's good for checking init on system without /sbin folder.
/sbin is not the only place used in the code logic. netclient executable file is also installed under /sbin. I am not sure if you are interested in making the change for installation directory. Otherwise the install will be still failed even the init check passed.

Sorry, i don't understand your proposal. This pr only modified the logic to find init, it doesn't affect the installation behavior of netclient.

As the issue description, Some Linux distros have no /sbin, such as NixOS . Current code logic, it does not work only when there is no /sbin. So the PR,

1. No impact to Linux distros with /sbin
2. It is helpful when Linux distrios without /sbin. But netclient does not work even with this PR. if searching with /sbin, it's used in other place besides GetInitType