Date: Thu, 27 Aug 2015 16:55:33 +0200 From: Damien Fleuriot <ml@my.gd> To: Pavel Timofeev <timp87@gmail.com> Cc: freebsd-hackers@freebsd.org, Devin Teske <dteske@freebsd.org> Subject: Re: How to control and setup service? Message-ID: <CAE63ME5s4uo1wn70qPMR5fSFjWtXvA8_4%2Bm3mpAqE2st=GrQRw@mail.gmail.com> In-Reply-To: <CAAoTqfvxUznJp%2BtguAaYQ=5HfKXTG%2BGxY644wvqm4e9=E8WuHw@mail.gmail.com> References: <CAAoTqfvxUznJp%2BtguAaYQ=5HfKXTG%2BGxY644wvqm4e9=E8WuHw@mail.gmail.com>
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On 27 August 2015 at 15:21, Pavel Timofeev <timp87@gmail.com> wrote:
> Hi! Good day!
>
> let me declare something first:
> HOPE="I just should know about that dir/sruff and hope that nothing
> will change in future releases";
>
>
> I'm trying to write some automation code to manipulate services.
> There is no problem with installing service, I can just use pkg(8) to
> search/install/remove service.
> Like following:
> # pkg install mysql56-server
> No problem. pkg(8) covers pretty much everything.
>
>
>
> But I have problems with starting and enabling services.
>
>
>
> Ok, to start a service we have rc scripts. If it's a base system
> service then it has rc script in /etc/rc.d dir.
> If a service is installed from packages (ports) then an rc script is
> in /usr/local/etc/rc.d dir.
> So, first, I should check one dir then another. But how can I be sure
> I'm looking in right directories?
> Is there any way to ask FreeBSD "Hey! Where is you startup dirs?". I'd
> say yes, but only partially.
>
> /etc/rc.d dir is hardcoded everywhere. So $HOPE, which is not good IMO.
>
>
Wow wow wow slow down here.
Base system init scripts have been in /etc/rc.d/ as long as I've used
FreeBSD which is from 4.4, perhaps even earlier.
You may have not noticed, but FreeBSD goes to great length to preserve
backwards compatibility.
> "/usr/local/etc/rc.d" is ${local_startup} var which is defined in
> /etc/defaults/rc.conf.
> I can actually ask FreeBSD about that by calling:
> # sh -c '. /etc/rc.subr; load_rc_config "XXX"; echo $local_startup'
> Good!
>
> But in geretal, there is no way to ask FreeBSD for a complete list of
> startup dirs. So $HOPE.
>
>
Neither should there be need for such a way.
Base system RC scripts are in /etc/rc.d/
Ports RC scripts are in /usr/local/etc/rc.d/
You should never see a RC script anywhere else, otherwise the package you
installed doesn't respect the hierarchy, and then that's the package
creator's problem, not the OS' .
Refer man 7 hier
> It would be pretty useful if I could ask FreeBSD for one variable like
> $all_startup, which would contain all of the startup dirs ("/etc/rc.d
> ${local_startup} ${new_startup_whatever}").
> And it would be great if "/etc/rc.d" was defined as variable too. Like
> ${system_startup}="/etc/rc.d" (which is not simple I believe, it's
> hardcoded everywhere!).
>
>
> Thank god, there is a alternative way to start/stop services!
> It's service(8) tool that can do this stuff for me. I can rely on it,
> because it's a base system tool and I'm sure it knows everything about
> startup dirs, no matter what FreeBSD release I'm using.
> IMO service(8) covers this use case.
> So we can forget my ideas above.
> Or realize them because it can be useful for such tools like
> service(8), sysrc(8) or even your_new_tool(8), and code written once
> would not break in future ;)
>
>
I'm not sure what you're trying to get at here.
>
>
> Ok, imagine I started/stopped service.
>
> Then, to enable/disable service I should know a lot of stuff!
>
>
Not that much as a matter of fact, since when you install a port it usually
tells you how to enable it.
Besides seeing you're actually installing a new service (as in, the system
didn't decide to install one for you, you're the one performing the
action), then you should read the documentation for said service, which
instructs you on how to enable/disable the service.
To enable/disable service first thing that I should know is $rcvar of
> a service. It can be different than $service name (which is rc script
> name).
> I should find rc script in right place, but thank again to service(8)
> tool. I just can ask it with:
> # service mysql-server rcvar
> and get the $rcvar of service, no matter where startup script is. Good!
>
> Second thing I should know is if it's already enabled/disabled.
> # service mysql-server rcvar
> will output YES/NO besides $rcvar var name.
> FreeBSD 10 got good command for rc scripts - "enabled", which would
> answer us by its exit code.
> # service mysql-server enabled; echo $?
> Excellent!
>
> Third thing I should know is how I have to enable/disable service.
> How would I do that? Where would I do that?
> Is it directly disabled (if $sysadmin2 set mysql_enable="NO"), if so -
> where, or it just not enabled anywhere?
> How many config files do you know which can be used to enable/disable
> (control) service? What's their precedence?
>
>
Well that one's rather easy isn't it ?
Stick to /etc/rc.conf and the problem will disappear all by itself ;)
> Well, most of us (probably) would use /etc/rc.conf to enable $service
> or to check if it's directly disabled. We would use $rcvar (!), not rc
> script name.
> But, FreeBSD has more places with higher precedence than /etc/rc.conf!
> It's /etc/rc.conf.local file,
> then /etc/rc.conf.d/$service file,
> then /etc/rc.conf.d/$service/* files.
> Then even /usr/local/etc/rc.conf.d/$service files and subdirs which
> appeared in FreeBSD 10!
>
> And there is no way to ask FreeBSD "Hey! Where is your config files to
> control services?".
> You can ask about them, but again, partially by running:
> # sh -c '. /etc/rc.subr; load_rc_config "XXX"; echo $rc_conf_files'
> which outputs "/etc/rc.conf /etc/rc.conf.local".
> Of course, there is no way to ask "Where this service is enabled/disabled?"
> So we can catch $rc_conf_files, but not a bunch of rc.conf.d dirs and
> subdirs. No way. So $HOPE, again, which is not good IMO.
> Why $HOPE? Because such change already happened between FreeBSD 9 and
> 10. So I should track such changes in my own code manually.
>
>
And what change would that be, that *wasn't documented in
/usr/src/UPDATING* or in the release notes ?
> As a way to solve this, I'd like to see some vars like $rc_conf_d_dirs
> which would point to "/etc/rc.conf.d
> ${local_startup%/rc.d}/rc.conf.d/". Or any way to get them.
> Now these dirs are "hardcoded" and used only in /etc/rc.subr here
> https://github.com/freebsd/freebsd/blob/master/etc/rc.subr#L1336-L1354.
> It's not used anywhere else.
>
>
And I, wouldn't.
You wanna make a mess out of your box by tossing startup definitions here
and there ?
Knock yourself out, but don't try to trivialise the malpractice by asking
that it be made easier.
I, on the other hand, am gonna stick to /etc/rc.conf
>
> Thank good we have an alternative to this hell of manual editing and
> going through the list of dirs! You can forget about anything above. I
> can rely on it, because it's in the base system and I'm sure it knows
> any cases.
> It's a ... Hmm, where is it?
> Turns out, we don't have such tool. We have only sysrc(8), but it can
> only edit $rc_conf_files in safe way. There is no support for
> rc.conf.d dirs in sysrc(8).
> And, in general, it's a tool to just `edit` $rc_conf_files, not to
> control and configure services.
>
>
Might that be because such a tool is not NEEDED, possibly ?
Your choice of phrasing makes it look like you're trying to fuck up your
box and using a condescending tone to bitch about the absence of tools to
help you do so.
> As a user I would love to have a cool tool to control and configure
> services in way like OpenBSD's rcctl(8) does
>
> http://www.openbsd.org/cgi-bin/man.cgi/OpenBSD-current/man8/rcctl.8?query=rcctl
> .
> # cooltool set mysql-server status on
> That's all. It would take care of those things like getting right
> $rcvar name, choose right rc config file to edit (remember, we have a
> lot of places to check, see above) and enable service, etc.
>
If your use case requires such a tool, for convenience or whatever, then
how about you hack one up ?
I'm convinced if other people have the same needs as you do, they'll very
much welcome such a program.
> This $cooltool can be an extended version of service(8) tool.
> More difficult example:
> # cooltool set flow_capture status on flags "-e 2200 -n 23 -N 0 -V 5"
> port "8787" datadir "/storage/flows/all_routers"
> would enable flow_capture service and set other stuff using right $rcvar.
> # cooltool get flow_capture
> would print all of the configured stuff for $service
> # cooltool get flow_capture status
> would print only a status YES/NO (don't forget about exit code ;) )
> and etc.
> IMO such tools would be useful even for ansible/puppet and friends.
> Not just for users ;)
>
>
> I'm really sorry if I misunderstand something and wasted your time!
> And I don't want to offend anyone in case I'm impolite!
>
> P.S. Do you have any ideas?
I myself dislike your idea and would rather stick to /etc/rc.conf.
Nobody's preventing you from getting to work on such a tool if you deem it
necessary for your needs though.
In fact, you could even create a port to do just that, in sysutils/ for
example.
Sky's the limit and all that stuff.
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