systemd-socket-proxyd(8)

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). 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.

OPTIONS

   The following options are understood:

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

   --version
       Print a short version string and exit.

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

       [Service]
       ExecStart=/lib/systemd/systemd-socket-proxyd /tmp/nginx.sock
       PrivateTmp=yes
       PrivateNetwork=yes

   Example 3. nginx.conf

       [...]
       server {
           listen       unix:/tmp/nginx.sock;
           [...]

   Example 4. Enabling the proxy

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

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

SEE ALSO

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

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Free and Open Source Software