=== NAME ===

duende - run a child process as a daemon 

=== DESCRIPTION ===

duende is a tool for users of init systems which require programs to 
provide their own daemonization. duende is not needed with systemd and 
other init systems which can provide daemonization for network 
services. duende makes a given child process a daemon. The standard 
output and standard error of the child process is logged via syslog() 
with a priority of LOG_INFO. 

=== SYSTEMD ===

duende should not be used if one uses systemd as the init process. 
Instead, files like this should be added to /etc/systemd/system

# Place this file here: 
# /etc/systemd/system/maradns.service 
# Then 
# systemctl enable maradns 
# systemctl start maradns 
[Unit] 
 After=network-online.target 
 ConditionPathExists=/usr/local/bin/maradns 
 Description=MaraDNS 
 Wants=network-online.target 
 
[Service] 
 ExecStart=/usr/local/bin/maradns 
 StandardOutput=journal 
 TimeoutSec=0 
 Type=exec 
 
[Install] 
 WantedBy=multi-user.target

When installed with make install, MaraDNS will look for systemd 
files, and install MaraDNS and Deadwood startup files. 

=== USAGE ===

duende (--pid=/path/to/file) child_process [ all subsequent arguments 
passed on to child ] 

=== DETAILS ===

When duende is invoked, it spawns two processes. In addition to 
spawning the daemonized child process, duende also spawns a process 
which reads and logs the standard output of the daemonized process. The 
parent process stays alive so as to monitor the daemonized process. If 
the optional --pid argument is supplied, duende will write its PID to 
the file specified by the argument. It is an error to supply the --pid 
argument without an equal sign and file name. 

duende requires a blank directory named /etc/maradns/logger to run. 

Should the parent duende process a HUP signal, duende will restart the 
child process. Should the daemonized or logging process received an 
untrapped HUP signal or exit with an exit code of 8, duende will 
restart the process. Should the daemonized or logging process exit for 
any other reason, duende will send the logger process a TERM signal and 
exit. Should the duende parent process receive a TERM or INT signal, 
duende sends all of its children TERM signals, then exits. 

The duende process must be started as the superuser; this is because 
Duende's intended child processes (maradns and zoneserver) need to bind 
to privileged ports, and because duende uses a setuid() call to change 
the user ID of the logging process to the user with ID 707. 

=== LOGGING ===

duende uses the syslog() facility to log the standard output of the 
program that it invokes. The name of the program (in other words, the 
"ident" given to openlog()) is the full path of the first argument 
given to duende. All messages created by the child process are sent to 
syslog() with a priority of LOG_INFO and a "facility" of LOG_DAEMON 
(daemon.info in /etc/syslog.conf); since daemon.info messages are not 
logged by default in FreeBSD, on FreeBSD systems messages generated by 
the child process are logged with a priority of LOG_ALERT and a 
"facility" of LOG_DAEMON (daemon.alert in /etc/syslog.conf). Should 
duende itself encounter an error, it will send messages to syslog() 
with a priority of LOG_ALERT. 

For example, suppose one invokes duende thusly:

	duende /usr/local/sbin/maradns

If invoked thusly, duende will log all messages with the "ident" 
(program name) of "/usr/local/sbin/maradns". If this is not desired, 
invoke duende with something like:

	export PATH=$PATH:/usr/local/sbin 
	duende maradns

This will log messages with a (more sensible) "ident" of maradns. 

Note: If a non-POSIX Bourne shell (such as csh, es, rc, or fish) is 
used to invoke MaraDNS, the above syntax needs to be changed. 

Also, the directory /etc/maradns/logger, while used by duende, is not 
used to store any log messages. That is unless, for some reason, one 
configures syslog to store messages there. 

=== EXAMPLES ===

Using duende to start maradns, where the mararc file is /etc/mararc.2

	duende maradns -f /etc/mararc.2

Using duende to start zoneserver, where the mararc file is 
/etc/mararc.4

	duende zoneserver -f /etc/mararc.4

=== BUGS ===

Duende assumes that all of its children are well-behaved, eating their 
vegetables, going to bed when told, and terminating when receiving a 
TERM signal. 

=== SEE ALSO ===

maradns(8), syslog(3) 
 http://www.maradns.org

=== LEGAL DISCLAIMER ===

THIS SOFTWARE IS PROVIDED BY THE AUTHORS ''AS IS'' AND ANY EXPRESS OR 
IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 
DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE FOR 
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
POSSIBILITY OF SUCH DAMAGE. 

=== AUTHOR ===

Duende and this man page are written by Sam Trenholme. D Richard Felker 
III provided some invaluable assistance with the piping code which 
duende uses.  

