Re: [SSSD] [PATCH] MONITOR: Poll for resolv.conf if not available during boot

[Michal Židek]

On 06/23/2015 01:48 PM, Jakub Hrozek wrote:
> On Wed, Jun 17, 2015 at 07:13:17PM +0200, Michal Židek wrote:
> > Hi,
> >
> > this patch partially solves the ticket
> > https://fedorahosted.org/sssd/ticket/2590
> >
> > It does not subscribe to the systemd dbus interface and does only
> > the polling (this would have to be done anyway for the case
> > the interface is not available).
> >
> > I will investigate how to add the systemd/dbus check as well,
> > but the attached patch should decrease priority of the ticket.
> >
> > Thanks,
> > Michal
> > From bb57b2bcba891cd395d795a7706cf2ea77f8bca2 Mon Sep 17 00:00:00 2001
> > From: =?UTF-8?q?Michal=20=C5=BDidek?= 
> > Date: Wed, 17 Jun 2015 18:54:14 +0200
> > Subject: [PATCH] MONITOR: Poll for resolv.conf if not available during boot
> >
> > If resolv.conf is not available when SSSD is starting,
> > check for its existence later.
> >
> > Ticket:
> > https://fedorahosted.org/sssd/ticket/2590
> >
> > src/monitor/monitor.c | 38 ++++++++++++++++++++++++++++++++++++--
> >   1 file changed, 36 insertions(+), 2 deletions(-)
> >
> > diff --git a/src/monitor/monitor.c b/src/monitor/monitor.c
> > index 01c882a..24fca28 100644
> > --- a/src/monitor/monitor.c
> > +++ b/src/monitor/monitor.c
> > @@ -2259,11 +2259,39 @@ static errno_t monitor_config_file_fallback(TALLOC_CTX *mem_ctx,
> >       return EOK;
> >   }
> >
> > +#define MISSING_RESOLV_CONF_POLL_TIME 10
> >
> > +static void missing_resolv_conf(struct tevent_context *ev,
> >                            struct tevent_timer *te,
> >                            struct timeval tv, void *data)
> >
> > +{
> > int ret;
> > struct mt_ctx *ctx = talloc_get_type(data, struct mt_ctx);
> > ret = monitor_config_file(ctx, ctx, RESOLV_CONF_PATH,
> >                          monitor_update_resolv, false);
> > if (ret == ENOENT) {
> >    tv = tevent_timeval_current_ofs(MISSING_RESOLV_CONF_POLL_TIME, 0);
> >    te = tevent_add_timer(ctx->ev, ctx, tv, missing_resolv_conf, ctx);
> >    if (te == NULL) {
> >        DEBUG(SSSDBG_FATAL_FAILURE,
> >              "tevent_add_timer failed. resolv.conf will be ignored.\n");
> >    }
> > } else if (ret != EOK) {
> >    DEBUG(SSSDBG_FATAL_FAILURE,
> >          "Monitor_config_file failed. resolv.conf will be ignored.\n");
> > }
>
> I think we should add signal_res_init() here, because in my testing the
> inotify watch is established if I mv a resolv.conf file into place, but
> the backends remain offline.

Yes, sorry for that. It worked during my testing because I had something
in /etc/hosts, so the missing resolv.conf was shadowed.
> We should also (in a different patch) change the DEBUG levels in
> monitor_config_file, because currently we print a 0x0010-level message.

Ok, but I think we should special case resolv.conf here. Otherwise
the missing (and not ignored) config file should always be reported.
> > return;
> >
> > +}

New patches attached.

Michal