duende - run a child process as a daemon
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
duende child_process [ all subsequent arguments passed on to child ]
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.
duende requires a blank directory named /etc/maradns/logger
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
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 66.
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:
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:
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.
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
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.
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.
Duende and this man page are written by Sam Trenholme. D Richard Felker
III provided some invaluable assistance with the piping code which