systemd-socket-proxydsystemdsystemd-socket-proxyd8systemd-socket-proxydBidirectionally proxy local sockets to another (possibly remote) socketsystemd-socket-proxydOPTIONSHOST:PORTsystemd-socket-proxydOPTIONSUNIX-DOMAIN-SOCKET-PATHDescriptionsystemd-socket-proxyd is a generic
socket-activated network socket forwarder proxy daemon for IPv4,
IPv6 and UNIX stream sockets. It may be used to bi-directionally
forward traffic from a local listening socket to a local or remote
destination socket.One use of this tool is to provide socket activation support
for services that do not natively support socket activation. On
behalf of the service to activate, the proxy inherits the socket
from systemd, accepts each client connection, opens a connection
to a configured server for each client, and then bidirectionally
forwards data between the two.This utility's behavior is similar to
socat1.
The main differences for systemd-socket-proxyd
are support for socket activation with
Accept=no and an event-driven
design that scales better with the number of
connections.OptionsThe following options are understood:Sets the maximum number of simultaneous connections, defaults to 256.
If the limit of concurrent connections is reached further connections will be refused.Sets the time before exiting when there are no connections, defaults to
infinity. Takes a unit-less value in seconds, or a time span value such
as 5min 20s.Exit statusOn success, 0 is returned, a non-zero failure
code otherwise.ExamplesSimple ExampleUse two services with a dependency and no namespace
isolation.proxy-to-nginx.socketproxy-to-nginx.servicenginx.confEnabling the proxyIf nginx.service has StopWhenUnneeded= set, then
passing to systemd-socket-proxyd allows
both services to stop during idle periods.Namespace ExampleSimilar as above, but runs the socket proxy and the main
service in the same private namespace, assuming that
nginx.service has
PrivateTmp= and
PrivateNetwork= set, too.proxy-to-nginx.socketproxy-to-nginx.servicenginx.confEnabling the proxySee Alsosystemd1,
systemd.socket5,
systemd.service5,
systemctl1,
socat1,
nginx1,
curl1