s6 supervision

s6 supervision

[billa chaitanya]

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Hi Team,

Is there an API/ command in s6 code to get the information of a process and
its pid by giving the service name that has started the process?

And does s6-svscan/s6-supervise have the knowledge of  service-name&
process name & process pid so that it can be fetched to another process
using IPC?


Thanks,
Chaitanya

Re: s6 supervision

[Colin Booth]

On Fri, Jan 29, 2021 at 11:17:00AM +0530, billa chaitanya wrote:
> Hi Team,
> 
> Is there an API/ command in s6 code to get the information of a process and
> its pid by giving the service name that has started the process?
>
I might be misreading your question but s6-svstat /path/to/servicedir I
believe answers your question, at least as far as reading what
s6-supervise knows about (pid, status, time in status, a few other
details). If you're on a system with a functional procfs you can then
use the pid to query most information from /proc/$pid.
> 
> And does s6-svscan/s6-supervise have the knowledge of  service-name&
> process name & process pid so that it can be fetched to another process
> using IPC?
> 
s6-supervise knows the process id of its primary child and as I
mentioned above you can ask it for that information via s6-svstat. It
does not know anything else about the process because it doesn't need
to. However, there are several options to s6-svstat that make output
information in easy-to-parse formats which make follow-on queries to
/proc trivial.

-- 
Colin Booth