[arch-general] systemd start a daemon after the Internet connection is established

[Rodrigo Rivas]

On Mon, Sep 16, 2013 at 9:50 AM, Bill Sun <cap.sensitive at gmail.com> wrote:

> On Sun, Sep 08, 2013 at 07:27:34PM +0200, Lukas Jirkovsky wrote:
> > On 8 September 2013 18:37, Bill Sun <cap.sensitive at gmail.com> wrote:
> > > When the server is connected to the Internet, this service file can
> > > launch the proxy successfully, but it doesn't work on system startup,
> > > supposedly due to the lack of an connection with Internet access. So I
> > > need systemd to make sure the connect has been established before it
> > > launch this daemon.
> > >
> > > Regards.
> >
> > Try network-online.target instead of network.target.
> No. It still doesn't work. I don't use NetworkManger, so my assumption
> is that the network-online.target does not exist at all. (Seems that
> `systemctl list-units` confirms that.)
>
> I use dhcpcd@%i to get an ip address from my router. Though the dhcpcd
> does start before my proxy daemon, the proxy daemon fails before the
> dhcpcd get an address.
>
> That is weird... dhcpcd at .service has the following lines:
Type=forking
ExecStart=/usr/sbin/dhcpcd -q -w %I

The -w option to the daemon (--waitip) is there so that it will not fork to
the background until an IP is available. And the systemd unit is of type
*forking*, so it will not be *started* until it has forked.

So, if your proxy has an "After=" relation to dhcpcd at eth0.service, then it
should not be started without an IP address.
Are you sure it so? You can check whether that's the case:

$ systemctl show myproxy.service | grep After=

-- 
Rodrigo