systemd-socket-proxyd(8) — Linux manual page


SYSTEMD-SOCKET-PROXYD(8)    systemd-socket-proxyd   SYSTEMD-SOCKET-PROXYD(8)

NAME         top

       systemd-socket-proxyd - Bidirectionally proxy local sockets to
       another (possibly remote) socket.

SYNOPSIS         top

       systemd-socket-proxyd [OPTIONS...] HOST:PORT

       systemd-socket-proxyd [OPTIONS...] UNIX-DOMAIN-SOCKET-PATH

DESCRIPTION         top

       systemd-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 socat(1). 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.

OPTIONS         top

       The following options are understood:

       -h, --help
           Print a short help text and exit.

           Print a short version string and exit.

       --connections-max=, -c
           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 STATUS         top

       On success, 0 is returned, a non-zero failure code otherwise.

EXAMPLES         top

   Simple Example
       Use two services with a dependency and no namespace isolation.

       Example 1. proxy-to-nginx.socket



       Example 2. proxy-to-nginx.service


           ExecStart=/usr/lib/systemd/systemd-socket-proxyd /run/nginx/socket

       Example 3. nginx.conf

           server {
               listen       unix:/run/nginx/socket;

       Example 4. Enabling the proxy

           # systemctl enable --now proxy-to-nginx.socket
           $ curl http://localhost:80/

       If nginx.service has StopWhenUnneeded= set, then passing
       --exit-idle-time= to systemd-socket-proxyd allows both services to
       stop during idle periods.

   Namespace Example
       Similar 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.

       Example 5. proxy-to-nginx.socket



       Example 6. proxy-to-nginx.service



       Example 7. nginx.conf

           server {
               listen       8080;

       Example 8. Enabling the proxy

           # systemctl enable --now proxy-to-nginx.socket
           $ curl http://localhost:80/

SEE ALSO         top

       systemd(1), systemd.socket(5), systemd.service(5), systemctl(1),
       socat(1), nginx(1), curl(1)

COLOPHON         top

       This page is part of the systemd (systemd system and service manager)
       project.  Information about the project can be found at 
       ⟨⟩.  If you have a bug
       report for this manual page, see
       ⟨⟩.  This
       page was obtained from the project's upstream Git repository
       ⟨⟩ on 2020-06-09.  (At that
       time, the date of the most recent commit that was found in the repos‐
       itory was 2020-06-09.)  If you discover any rendering problems in
       this HTML version of the page, or you believe there is a better or
       more up-to-date source for the page, or you have corrections or
       improvements to the information in this COLOPHON (which is not part
       of the original manual page), send a mail to

systemd 245                                         SYSTEMD-SOCKET-PROXYD(8)

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