1SYSTEMD-SOCKET-PROXYD(8)     systemd-socket-proxyd    SYSTEMD-SOCKET-PROXYD(8)
2
3
4

NAME

6       systemd-socket-proxyd - Bidirectionally proxy local sockets to another
7       (possibly remote) socket
8

SYNOPSIS

10       systemd-socket-proxyd [OPTIONS...] HOST:PORT
11
12       systemd-socket-proxyd [OPTIONS...] UNIX-DOMAIN-SOCKET-PATH
13

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.
31

OPTIONS

33       The following options are understood:
34
35       -h, --help
36           Print a short help text and exit.
37
38       --version
39           Print a short version string and exit.
40
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.
45
46       --exit-idle-time=
47           Sets the time before exiting when there are no connections,
48           defaults to infinity. Takes a unit-less value in seconds, or a time
49           span value such as "5min 20s".
50

EXIT STATUS

52       On success, 0 is returned, a non-zero failure code otherwise.
53

EXAMPLES

55   Simple Example
56       Use two services with a dependency and no namespace isolation.
57
58       Example 1. proxy-to-nginx.socket
59
60           [Socket]
61           ListenStream=80
62
63           [Install]
64           WantedBy=sockets.target
65
66       Example 2. proxy-to-nginx.service
67
68           [Unit]
69           Requires=nginx.service
70           After=nginx.service
71           Requires=proxy-to-nginx.socket
72           After=proxy-to-nginx.socket
73
74           [Service]
75           Type=notify
76           ExecStart=/usr/lib/systemd/systemd-socket-proxyd /run/nginx/socket
77           PrivateTmp=yes
78           PrivateNetwork=yes
79
80       Example 3. nginx.conf
81
82           [...]
83           server {
84               listen       unix:/run/nginx/socket;
85               [...]
86
87       Example 4. Enabling the proxy
88
89           # systemctl enable --now proxy-to-nginx.socket
90           $ curl http://localhost:80/
91
92       If nginx.service has StopWhenUnneeded= set, then passing
93       --exit-idle-time= to systemd-socket-proxyd allows both services to stop
94       during idle periods.
95
96   Namespace Example
97       Similar as above, but runs the socket proxy and the main service in the
98       same private namespace, assuming that nginx.service has PrivateTmp= and
99       PrivateNetwork= set, too.
100
101       Example 5. proxy-to-nginx.socket
102
103           [Socket]
104           ListenStream=80
105
106           [Install]
107           WantedBy=sockets.target
108
109       Example 6. proxy-to-nginx.service
110
111           [Unit]
112           Requires=nginx.service
113           After=nginx.service
114           Requires=proxy-to-nginx.socket
115           After=proxy-to-nginx.socket
116           JoinsNamespaceOf=nginx.service
117
118           [Service]
119           Type=notify
120           ExecStart=/usr/lib/systemd/systemd-socket-proxyd 127.0.0.1:8080
121           PrivateTmp=yes
122           PrivateNetwork=yes
123
124       Example 7. nginx.conf
125
126           [...]
127           server {
128               listen       8080;
129               [...]
130
131       Example 8. Enabling the proxy
132
133           # systemctl enable --now proxy-to-nginx.socket
134           $ curl http://localhost:80/
135

SEE ALSO

137       systemd(1), systemd.socket(5), systemd.service(5), systemctl(1),
138       socat(1), nginx(1), curl(1)
139
140
141
142systemd 254                                           SYSTEMD-SOCKET-PROXYD(8)