systemd-socket-activate — Test socket activation of daemons
systemd-socket-activate [OPTIONS...] COMMAND
[ARGS...]
systemd-socket-activate may be used to launch a socket-activated service program from the command line for testing purposes. It may also be used to launch individual instances of the service program per connection.
The daemon to launch and its options should be specified after options intended for systemd-socket-activate.
If the --inetd option is given, the socket file descriptor will be used as the standard
input and output of the launched process. Otherwise, standard input and output will be inherited, and sockets will
be passed through file descriptors 3 and higher. Sockets passed through $LISTEN_FDS to
systemd-socket-activate will be passed through to the daemon, in the original positions. Other sockets
specified with --listen= will use consecutive descriptors. By default,
systemd-socket-activate listens on a stream socket, use --datagram and
--seqpacket to listen on datagram or sequential packet sockets instead (see below).
-l address, --listen=address¶Listen on this address.
Takes a string like "2000" or
"127.0.0.1:2001".
-a, --accept¶Launch an instance of the service program for each connection and pass the connection
socket. May not be combined with --now.
-d, --datagram¶Listen on a datagram socket (SOCK_DGRAM), instead of a stream socket
(SOCK_STREAM). May not be combined with --seqpacket.
--seqpacket¶Listen on a sequential packet socket (SOCK_SEQPACKET), instead of a stream
socket (SOCK_STREAM). May not be combined with
--datagram.
--inetd¶Use the inetd protocol for passing file descriptors, i.e. as standard input and standard
output, instead of the new-style protocol for passing file descriptors using $LISTEN_FDS
(see above).
-E VAR[=VALUE], --setenv=VAR[=VALUE]¶Add this variable to the environment of the
launched process. If VAR is
followed by "=", assume that it is a
variable–value pair. Otherwise, obtain the value from the
environment of systemd-socket-activate itself.
--fdname=NAME[:NAME…]¶Specify names for the file descriptors passed. This is equivalent to setting
FileDescriptorName= in socket unit files, and enables use of
sd_listen_fds_with_names(3).
Multiple entries may be specifies using separate options or by separating names with colons
(":") in one option. In case more names are given than descriptors, superfluous ones will be
ignored. In case less names are given than descriptors, the remaining file descriptors will be unnamed.
--now¶Start the service program instantly, instead of waiting for a connection on the
socket(s). May not be combined with --accept.
-h, --help¶--version¶$LISTEN_FDS, $LISTEN_PID, $LISTEN_FDNAMES¶See sd_listen_fds(3).
$SYSTEMD_LOG_TARGET, $SYSTEMD_LOG_LEVEL, $SYSTEMD_LOG_TIME, $SYSTEMD_LOG_COLOR, $SYSTEMD_LOG_LOCATION¶Same as in systemd(1).
Example 2. Run a socket-activated instance of systemd-journal-gatewayd(8)
$ systemd-socket-activate -l 19531 /usr/lib/systemd/systemd-journal-gatewayd