# phpman > man > systemd-socket-proxyd(8)

[SYSTEMD-SOCKET-PROXYD(8)](https://www.chedong.com/phpMan.php/man/SYSTEMD-SOCKET-PROXYD/8/markdown)                systemd-socket-proxyd               [SYSTEMD-SOCKET-PROXYD(8)](https://www.chedong.com/phpMan.php/man/SYSTEMD-SOCKET-PROXYD/8/markdown)



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

## SYNOPSIS
       **systemd-socket-proxyd** [_OPTIONS_...] _HOST_:_PORT_

       **systemd-socket-proxyd** [_OPTIONS_...] _UNIX-DOMAIN-SOCKET-PATH_

## DESCRIPTION
       **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)](https://www.chedong.com/phpMan.php/man/socat/1/markdown). 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
       The following options are understood:

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

### --version
           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.

### --exit-idle-time=
           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
       On success, 0 is returned, a non-zero failure code otherwise.

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

### Example 1. proxy-to-nginx.socket

           [Socket]
           ListenStream=80

           [Install]
           WantedBy=sockets.target

### Example 2. proxy-to-nginx.service

           [Unit]
           Requires=nginx.service
           After=nginx.service
           Requires=proxy-to-nginx.socket
           After=proxy-to-nginx.socket

           [Service]
           ExecStart=/lib/systemd/systemd-socket-proxyd /run/nginx/socket
           PrivateTmp=yes
           PrivateNetwork=yes

### 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

           [Socket]
           ListenStream=80

           [Install]
           WantedBy=sockets.target

### Example 6. proxy-to-nginx.service

           [Unit]
           Requires=nginx.service
           After=nginx.service
           Requires=proxy-to-nginx.socket
           After=proxy-to-nginx.socket
           JoinsNamespaceOf=nginx.service

           [Service]
           ExecStart=/lib/systemd/systemd-socket-proxyd 127.0.0.1:8080
           PrivateTmp=yes
           PrivateNetwork=yes

### 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
       [**systemd**(1)](https://www.chedong.com/phpMan.php/man/systemd/1/markdown), [**systemd.socket**(5)](https://www.chedong.com/phpMan.php/man/systemd.socket/5/markdown), [**systemd.service**(5)](https://www.chedong.com/phpMan.php/man/systemd.service/5/markdown), [**systemctl**(1)](https://www.chedong.com/phpMan.php/man/systemctl/1/markdown), [**socat**(1)](https://www.chedong.com/phpMan.php/man/socat/1/markdown), [**nginx**(1)](https://www.chedong.com/phpMan.php/man/nginx/1/markdown), [**curl**(1)](https://www.chedong.com/phpMan.php/man/curl/1/markdown)



systemd 249                                                                 [SYSTEMD-SOCKET-PROXYD(8)](https://www.chedong.com/phpMan.php/man/SYSTEMD-SOCKET-PROXYD/8/markdown)