unix-dgram() Source/Destination Driver

The unix-dgram() source driver open an AF_UNIX socket and start listening on it for messages. Whereas unix-dgram() destination driver send messages to a UNIX domain socket.

Important Information

Unix-dgram() is used on BSDs and uses SOCK_DGRAM semantics: this may result in lost local messages if the system is overloaded.

In the official documentation, /dev/log is the default entry for system logging. This, in fact, is a socket, not a regular file or a pipe. MacOS, however, uses /var/run/syslog for the same. This needs to be kept in mind while referring to the documentation.

Status

x86	Works
ARM	Works

How to Test

To test the unix-dgram() drivers, we will run two instances of syslog-ng. One where we are transmitting data to a socket using the unix-dgram() destination driver that needs to be tested. And another that will listen for the data on the socket using the unix-stream() source driver.

Source Configuration File

@version: 3.31
@include "scl.conf"

options {
    stats-freq(10);
    time-reopen(10);
};

source s_dgram {
    unix-dgram("/var/run/syslog");
};

destination console{
    file(/dev/stdout);
};

log {
    source(s_dgram);
    destination(console);
};

Note: We need to run the source driver first as it will open the socket to which the destination driver connects to.

Destination Configuration File

@version: 3.31
@include "scl.conf"

options {
    stats-freq(10);
    time-reopen(10);
};

source custom {
    example-msg-generator(
        num(20)
        freq(5)
        template("Message to Default Socket")
    );
};

destination d_dgram {
    unix-dgram("/var/run/syslog");
};

log {
    source(custom);
    destination(d_dgram);
};

Proof