systemd-socket-proxydsystemdDeveloperDavidStraussdavid@davidstrauss.netDeveloperLennartPoetteringlennart@poettering.netsystemd-socket-proxyd1systemd-socket-proxydBidirectionally proxy local sockets to another (possibly remote) socket.systemd-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=false and an event-driven
design that scales better with the number of
connections.OptionsThe following options are understood:Restricts listening to a
single inherited socket, specified
as a file descriptor. By default,
the proxy listens on all inherited
sockets.Prints a short help
text and exits.Prints a version
string and exits.Exit statusOn success, 0 is returned, a non-zero failure
code otherwise.ExamplesDirect-Use ExampleUse two services with a dependency
and no namespace isolation./etc/systemd/system/proxy-to-nginx.socket/etc/systemd/system/proxy-to-nginx.service/etc/nginx/nginx.confIndirect-Use ExampleUse a shell script to isolate the
service and proxy into the same namespace.
This is particularly useful for running
TCP-only daemons without the daemon
affecting ports on regular
interfaces.
/etc/systemd/system/proxy-with-nginx.socket
/etc/systemd/system/proxy-with-nginx.service
/usr/bin/socket-proxyd-nginx.shMake it executable:
/etc/nginx/nginx.confMultiple Listeners with Multiple DestinationsWhen using namespaces, it may be useful to
have multiple listeners with each going to a unique
destination. systemd always passes sockets into
services in the order specified in the socket
unit, beginning with file descriptor 3.In this example, port 80
will proxy to localhost:8080,
and port 443 will proxy to
localhost:8443./etc/systemd/system/multi-destination.socket/etc/systemd/system/multi-destination.service
/usr/bin/socket-proxyd-multi-destination.shMake it executable:See Alsosystemd1,
systemd.socket5,
systemd.service5,
systemctl1,
socat1