1SYSTEMD-SOCKET-PROXYD(8)     systemd-socket-proxyd    SYSTEMD-SOCKET-PROXYD(8)
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NAME

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

10       systemd-socket-proxyd [OPTIONS...] HOST:PORT
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12       systemd-socket-proxyd [OPTIONS...] UNIX-DOMAIN-SOCKET-PATH
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DESCRIPTION

15       systemd-socket-proxyd is a generic socket-activated network socket
16       forwarder proxy daemon for IPv4, IPv6 and UNIX stream sockets. It may
17       be used to bi-directionally forward traffic from a local listening
18       socket to a local or remote destination socket.
19
20       One use of this tool is to provide socket activation support for
21       services that do not natively support socket activation. On behalf of
22       the service to activate, the proxy inherits the socket from systemd,
23       accepts each client connection, opens a connection to a configured
24       server for each client, and then bidirectionally forwards data between
25       the two.
26
27       This utility's behavior is similar to socat(1). The main differences
28       for systemd-socket-proxyd are support for socket activation with
29       "Accept=no" and an event-driven design that scales better with the
30       number of connections.
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OPTIONS

33       The following options are understood:
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35       -h, --help
36           Print a short help text and exit.
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38       --version
39           Print a short version string and exit.
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41       --connections-max=, -c
42           Sets the maximum number of simultaneous connections, defaults to
43           256. If the limit of concurrent connections is reached further
44           connections will be refused.
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EXIT STATUS

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

50   Simple Example
51       Use two services with a dependency and no namespace isolation.
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53       Example 1. proxy-to-nginx.socket
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55           [Socket]
56           ListenStream=80
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58           [Install]
59           WantedBy=sockets.target
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61       Example 2. proxy-to-nginx.service
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63           [Unit]
64           Requires=nginx.service
65           After=nginx.service
66           Requires=proxy-to-nginx.socket
67           After=proxy-to-nginx.socket
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69           [Service]
70           ExecStart=/usr/lib/systemd/systemd-socket-proxyd /run/nginx/socket
71           PrivateTmp=yes
72           PrivateNetwork=yes
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74       Example 3. nginx.conf
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76           [...]
77           server {
78               listen       unix:/run/nginx/socket;
79               [...]
80
81       Example 4. Enabling the proxy
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83           # systemctl enable --now proxy-to-nginx.socket
84           $ curl http://localhost:80/
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86   Namespace Example
87       Similar as above, but runs the socket proxy and the main service in the
88       same private namespace, assuming that nginx.service has PrivateTmp= and
89       PrivateNetwork= set, too.
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91       Example 5. proxy-to-nginx.socket
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93           [Socket]
94           ListenStream=80
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96           [Install]
97           WantedBy=sockets.target
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99       Example 6. proxy-to-nginx.service
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101           [Unit]
102           Requires=nginx.service
103           After=nginx.service
104           Requires=proxy-to-nginx.socket
105           After=proxy-to-nginx.socket
106           JoinsNamespaceOf=nginx.service
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108           [Service]
109           ExecStart=/usr/lib/systemd/systemd-socket-proxyd 127.0.0.1:8080
110           PrivateTmp=yes
111           PrivateNetwork=yes
112
113       Example 7. nginx.conf
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115           [...]
116           server {
117               listen       8080;
118               [...]
119
120       Example 8. Enabling the proxy
121
122           # systemctl enable --now proxy-to-nginx.socket
123           $ curl http://localhost:80/
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SEE ALSO

126       systemd(1), systemd.socket(5), systemd.service(5), systemctl(1),
127       socat(1), nginx(1), curl(1)
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131systemd 241                                           SYSTEMD-SOCKET-PROXYD(8)