On 26 May 2010 09:27, Howard Chu <hyc_at_highlandsun.com> wrote:
> Dima Q wrote:
>>
>> On 05/26/10 01:25, Daniel Stenberg wrote:
>>>
>>> On Tue, 25 May 2010, Dima Tisnek wrote:
>>>
>>>> The long-running process tries to access the server, the lookup fails
>>>> Later when a wireless network is discovered, I'd like to be able to
>>>> get libcurl to talk to the server, but alas! the resolv data is
>>>> cached somewhere and I can't get through to c-ares (or libc?) to
>>>> re-read /etc/resolv.conf.
>>>
>>> libc usally provides such a function for the stock resolver, but
>>> c-ares doesn't.
>>>
>>> This is a problem that we're aware of but it has not been solved yet...
>>>
>> I could come up with a patch along the lines of glibc patches (ubuntu,
>> fedora) where system config files are stat()ed and if needed, reloaded
>> on every init. That would only work on unix, so advice on how to guard
>> the changes from other platforms is appreciated.
>
> In my experience, it's better not to have a dynamic /etc/resolv.conf at all.
> Instead, run a local caching DNS server and hardwire /etc/resolv.conf to
> point to localhost. On my machines I run dnsmasq with its DBUS interface
> enabled. I have NetworkManager patched to send the current list of DNS
> servers to dnsmasq whenever NM connects to a network. It's a much more
> reliable solution and no unnecessary overhead.

It sounds like he's on an embedded system, so I doubt he's using dbus.
 dnsmasq might still be an option, though. You can tell dnsmasq to
use an arbitrary file as its resolv.conf (i.e. what upstream
nameservers it uses), and the documentation implies that it polls this
file (or can be made to).

-- 
Michael Wood <esiotrot_at_gmail.com>
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