60 lines
2.9 KiB
Plaintext
60 lines
2.9 KiB
Plaintext
In many cases, network configuration makes it necessary to run several daemons:
|
|
dhcp, zeroconf, ppp, openvpn and such. They need to be controlled,
|
|
and in many cases you also want to babysit them. runsvdir is a good tool for this.
|
|
examples/var_service directory provides a few examples. It is meant to be used
|
|
this way: copy it somewhere (say, /var/service) and run something like
|
|
|
|
env - PATH=... <other vars=...> runsvdir /var/service &
|
|
|
|
from one of system startup scripts. (Google "man runsvdir" and "man runsv"
|
|
for more info about these tools).
|
|
|
|
Some existing examples:
|
|
|
|
var_service/dhcp_if -
|
|
controls a udhcpc instance which provides dhpc-assigned IP
|
|
address on interface named "if". Copy/rename this directory as needed to run
|
|
udhcpc on other interfaces (var_service/dhcp_if/run script uses _foo suffix
|
|
or the parent directory as interface name). When IP address is obtained or lost,
|
|
var_service/dhcp_if/dhcp_handler is run. It saves new config data to
|
|
/var/run/service/fw/dhcp_if.ipconf and (re)starts /var/service/fw service.
|
|
This example can be used as a template for other dynamic network link services
|
|
(ppp/vpn/zcip).
|
|
|
|
var_service/ifplugd_if -
|
|
watches link status of interface if. Downs and ups /var/service/dhcp_if
|
|
service accordingly. In effect, it allows you to unplug/plug-to-different-network
|
|
and have your IP properly re-negotiated at once.
|
|
|
|
var_service/dhcp_if_pinger -
|
|
Uses var_service/dhcp_if's data (/var/service/dhcp_if/dhcp_if.out file)
|
|
to determine router IP. Pings it. If ping fails, restarts /var/service/dhcp_if
|
|
service. Basically, an example of watchdog service for networks
|
|
which are not reliable and need babysitting.
|
|
|
|
var_service/fw -
|
|
An *one-shot* service which reconfigures network based on current known state
|
|
of ALL interfaces. Uses conf/*.ipconf (static config) and /var/run/service/fw/*.ipconf
|
|
(dynamic config from dhcp/ppp/vpn/etc) to determine what to do.
|
|
One-shot-ness of this service means that it shuts itself off after single run.
|
|
IOW: it is not a constantly running daemon sort of thing.
|
|
It starts, it configures the network, it shuts down, all done
|
|
(unlike infamous NetworkManagers which sit in RAM forever, doing hell knows what).
|
|
|
|
However, any dhcp/ppp/vpn or similar service can restart it anytime
|
|
when it senses the change in network configuration.
|
|
This even works while fw service runs: if dhcp signals fw to (re)start
|
|
while fw runs, fw will not stop after its execution, but will re-execute once,
|
|
picking up dhcp's new configuration.
|
|
This is achieved very simply by having
|
|
# Make ourself one-shot
|
|
sv o .
|
|
at the very beginning of fw/run script, not at the end.
|
|
Therefore, any "sv u /var/run/service/fw" command by any other
|
|
script "undoes" o(ne-shot) command if fw still runs, thus
|
|
runsv will rerun it; or start it in a normal way if fw is not running.
|
|
|
|
System administrators are expected to edit fw/run script, since
|
|
network configuration needs are likely to be very complex and different
|
|
for non-trivial installations.
|