[prev in list] [next in list] [prev in thread] [next in thread] 

List:       gentoo-dev
Subject:    Re: [gentoo-dev] Providing a `service` scripts that speaks OpenRC and systemd
From:       Tom H <tomh0665 () gmail ! com>
Date:       2017-09-30 22:55:59
Message-ID: CAOdo=SyatPx7m3egU_z1wXXyXs9HQFULJuh3usS3Ex=dxYLMdQ () mail ! gmail ! com
[Download RAW message or body]

On Sat, Sep 30, 2017 at 12:20 AM, Walter Dnes <waltdnes@waltdnes.org> wrote:
> On Thu, Sep 28, 2017 at 04:27:31PM -0500, Austin English wrote


>> While having the pleasure of working with some proprietary software
>> recently, I was asked to run `service foo restart`, and was surprised to
>> see:
>> foobar ~ # service foo restart
>>  * service: service `foo' does not exist
>
> Ridiculous!  We need to develop one universal standard that covers
> everyone's use cases.  https://xkcd.com/927/
>
> But if you insist, why not just set up a short bash script called
> "service" rather than monkeying with every init system's internals?
>
> #!/bin/bash
> if [[ <condition_running_systemd> ]] ; then
>    systemctl ${2} ${1}
> elif [[ <condition_running_initrc> ]] ; then
>    /etc/init.d/${1} ${2}
> elif [[ <condition_running_some_other_init> ]] ; then
>   <do whatever that init system requires>
> else
>    echo "ERROR: Unsupported init system; 'service' call failed"
> fi

With a "[ $# -eq 2 ]" test and with "env -i set_some_envvars
/etc/init.d/${1} ${2}" (and use "rc-service ${1} ${2}" instead of
"/etc/init.d/${1} ${2}")


> This can handle a large number of different inits, with as many "elif"
> lines as you care to add. But, how do we reliably detect the currently
> running init system? Are there running processes, or entries in /sys/
> or /proc/ or /dev that are unique to to each init system?

It's not init that you want to check, it's rc.

For openrc, "[ -d /run/openrc ]" should do the trick.

For systemd, the canonical way is "[ -d /run/systemd/system ]".

[prev in list] [next in list] [prev in thread] [next in thread]