Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.debian.user > #226138 > unrolled thread

dns cache for localdomain via djbdns

Back to article view | Back to linux.debian.user

Contents

  dns cache for localdomain via djbdns Patrick Frank <sfsoc@gmx.de> - 2020-08-12 15:10 +0200
    Re: dns cache for localdomain via djbdns Greg Wooledge <wooledg@eeg.ccf.org> - 2020-08-12 15:10 +0200
      Re: dns cache for localdomain via djbdns Dan Ritter <dsr@randomstring.org> - 2020-08-12 15:30 +0200
        Re: dns cache for localdomain via djbdns Greg Wooledge <wooledg@eeg.ccf.org> - 2020-08-12 16:00 +0200
        Re: dns cache for localdomain via djbdns Patrick Frank <sfsoc@gmx.de> - 2020-08-12 16:00 +0200
          Re: dns cache for localdomain via djbdns <tomas@tuxteam.de> - 2020-08-12 18:20 +0200

#226138 — dns cache for localdomain via djbdns

Hello,

on a Debian 10 host I created a virtual machine with very basic features
to build a dns cache for my home network with djbdns. I fail to understand
how Daemontools are used properly.

Following the instructions on http://cr.yp.to/djbdns/install.html went okay.
http://cr.yp.to/djbdns/run-cache-x.html at step 5 is where I am stuck.

When I go to /service/dnscache and execute "run" it says "starting" so I
try svstat /service/dnscache which outputs:
"/service/dnscache: unable to open supervise/ok: file does not exist"

Any hints, please?

P.

[toc] | [next] | [standalone]

#226139

On Wed, Aug 12, 2020 at 02:59:23PM +0200, Patrick Frank wrote:
> Hello,
> 
> on a Debian 10 host I created a virtual machine with very basic features
> to build a dns cache for my home network with djbdns. I fail to understand
> how Daemontools are used properly.
> 
> Following the instructions on http://cr.yp.to/djbdns/install.html went okay.
> http://cr.yp.to/djbdns/run-cache-x.html at step 5 is where I am stuck.
> 
> When I go to /service/dnscache and execute "run" it says "starting" so I
> try svstat /service/dnscache which outputs:
> "/service/dnscache: unable to open supervise/ok: file does not exist"

You can execute the "./run" script by hand for testing purposes, to
make sure you've written it correctly, but that's not how daemontools
will run it.  If your test is successful, you should Ctrl-C (or otherwise
terminate) the ./run script that you ran manually.  Make sure it dies.

You tell daemontools to run the service by creating a symbolic link
from the /service directory to the directory where the run script
lives.

For example:

unicorn:~$ ls -l /service
total 0
lrwxrwxrwx 1 root root 13 Jan 12  2018 dnscache -> /etc/dnscache/
lrwxrwxrwx 1 root root 39 Jan 12  2018 qmail-deliverabled -> /var/qmail/supervise/qmail-deliverabled/
lrwxrwxrwx 1 root root 31 Jan 12  2018 qmail-send -> /var/qmail/supervise/qmail-send/
lrwxrwxrwx 1 root root 28 Jan 12  2018 qpsmtpd -> /var/qmail/supervise/qpsmtpd/

unicorn:~$ ls -l /etc/dnscache/
total 24
drwxr-sr-x 2 root root 4096 Jan 12  2018 env/
drwxr-sr-x 4 root root 4096 Jan 12  2018 log/
drwxr-sr-x 4 root root 4096 Jan 12  2018 root/
-rwxr-xr-x 1 root root  142 Jan 12  2018 run*
-rw------- 1 root root  128 Jan 12  2018 seed
drwx--S--- 2 root root 4096 Aug  2 09:00 supervise/

The presence of the symlink /service/dnscache is picked up by svscan,
which launches a supervisor process.

[toc] | [prev] | [next] | [standalone]

#226140

Greg Wooledge wrote: 
> On Wed, Aug 12, 2020 at 02:59:23PM +0200, Patrick Frank wrote:
> > Hello,
> > 
> > on a Debian 10 host I created a virtual machine with very basic features
> > to build a dns cache for my home network with djbdns. I fail to understand
> > how Daemontools are used properly.
> > 
> > Following the instructions on http://cr.yp.to/djbdns/install.html went okay.
> > http://cr.yp.to/djbdns/run-cache-x.html at step 5 is where I am stuck.
> > 
> > When I go to /service/dnscache and execute "run" it says "starting" so I
> > try svstat /service/dnscache which outputs:
> > "/service/dnscache: unable to open supervise/ok: file does not exist"
> 
> You can execute the "./run" script by hand for testing purposes, to
> make sure you've written it correctly, but that's not how daemontools
> will run it.  If your test is successful, you should Ctrl-C (or otherwise
> terminate) the ./run script that you ran manually.  Make sure it dies.
> 
> You tell daemontools to run the service by creating a symbolic link
> from the /service directory to the directory where the run script
> lives.
> 
> For example:
> 
> unicorn:~$ ls -l /service
> total 0
> lrwxrwxrwx 1 root root 13 Jan 12  2018 dnscache -> /etc/dnscache/
> lrwxrwxrwx 1 root root 39 Jan 12  2018 qmail-deliverabled -> /var/qmail/supervise/qmail-deliverabled/
> lrwxrwxrwx 1 root root 31 Jan 12  2018 qmail-send -> /var/qmail/supervise/qmail-send/
> lrwxrwxrwx 1 root root 28 Jan 12  2018 qpsmtpd -> /var/qmail/supervise/qpsmtpd/
> 
> unicorn:~$ ls -l /etc/dnscache/
> total 24
> drwxr-sr-x 2 root root 4096 Jan 12  2018 env/
> drwxr-sr-x 4 root root 4096 Jan 12  2018 log/
> drwxr-sr-x 4 root root 4096 Jan 12  2018 root/
> -rwxr-xr-x 1 root root  142 Jan 12  2018 run*
> -rw------- 1 root root  128 Jan 12  2018 seed
> drwx--S--- 2 root root 4096 Aug  2 09:00 supervise/
> 
> The presence of the symlink /service/dnscache is picked up by svscan,
> which launches a supervisor process.

This is all correct, but in addition:

svc -d /service/dnscache
  brings it down via the supervisor, similar to the action of
"service dnscache stop" or "/etc/init.d/dnscache stop"

svc -u /service/dnscache
  should start running it again

All of this clashes with manual invocation of ./run, so that has
to be killed before daemontools can take over.

-dsr-

[toc] | [prev] | [next] | [standalone]

#226141

On Wed, Aug 12, 2020 at 03:51:11PM +0200, Patrick Frank wrote:
> Greg writes: You can execute the "./run" script by hand for testing
> purposes [...]
> 
> When I tried "exec envuidgid Gnscache ..." it logged me out.

So don't do that.  Test it with ./run instead, like I said.

> Greg writes: unicorn:~$ ls -l /etc/dnscache/
> 
> This directory is missing the "supervise" directory.

Because you haven't started the service yet.  That will be created
once daemontools runs it for the first time.

> Dan writes: svc -d /service/dnscache
> 
> It outputs: unable to control /service/dnscache: file does not exist

Because you haven't started the service yet.

You need to create the symlink to start the service.

[toc] | [prev] | [next] | [standalone]

#226142

On 12.08.20 15:28, Dan Ritter wrote:
> Greg Wooledge wrote:
>> On Wed, Aug 12, 2020 at 02:59:23PM +0200, Patrick Frank wrote:


Greg writes: You can execute the "./run" script by hand for testing
purposes [...]

When I tried "exec envuidgid Gnscache ..." it logged me out.


Greg writes: unicorn:~$ ls -l /etc/dnscache/

This directory is missing the "supervise" directory.


Dan writes: svc -d /service/dnscache

It outputs: unable to control /service/dnscache: file does not exist


P.

[toc] | [prev] | [next] | [standalone]

#226147

[Multipart message — attachments visible in raw view] — view raw

On Wed, Aug 12, 2020 at 03:51:11PM +0200, Patrick Frank wrote:
> 
> On 12.08.20 15:28, Dan Ritter wrote:
> >Greg Wooledge wrote:
> >>On Wed, Aug 12, 2020 at 02:59:23PM +0200, Patrick Frank wrote:
> 
> 
> Greg writes: You can execute the "./run" script by hand for testing
> purposes [...]
> 
> When I tried "exec envuidgid Gnscache ..." it logged me out.

No, not "it" logged you out. When you say "exec", you say "replace
the currently running process by that other". When  "that other"
terminates... it's done. So it won't come back to your shell. It's
gone. Basically, with "exec" you logged you out yourself, kind of.

Cheers
 - t

[toc] | [prev] | [standalone]

Back to top | Article view | linux.debian.user

csiph-web