Signals are trivial if you know the PID. You can turn your daemon on and off at will. djb's Gift to Us By Steve Litt I don't know djb. MSI (s) (10:9C) [15:22:17:953]: Executing op: CustomActionSchedule(Action=DaemonDriverInstall,Ac tionType=3073,Source=BinaryData,Target=_DaemonDriv [email protected],CustomActionData=d347bus;d347prt) MSI (s) (10C) [15:22:17:953]: Invoking remote custom action. http://comscity.net/daemon-tools/daemon-tools-usb-bootable.html
We can remedy that: 1 #!/bin/bash 2 PATH=/usr/local/bin:/usr/bin:/bin 3 mkdir -p /var/log/carbon 4 exec multilog t s10485760 n5 '!tai64nlocal' /var/log/carbon And now, the only problem left is multilog is running as Steve can be reached at his email address. It knows when the process terminates because the pipe to the process is closed. Now do the following, as user root: cd /service svc -d hello cd /scratch/service/hello cp -p run run.new Warning!
The following is an example: exec envuidgid slitt envdir ./env setuidgid slitt /d/at/python/littcron/littcron.py /d/at/python/littcron/crontab Yes, as a matter of fact, I did make a crude cron replacment out of Python and That makes his stuff easy to understand, even without reading his code, makes it likely to compile most places, and makes his stuff just work, consistently. In this case, it's a simple script, but multilog supports writing to multiple files and log rotations at different sizes for different directories. I want to eliminate /service/telnetd.
Beyond the systemd connections, many who have used daemontools believe it to be exemplary sofrtware that does one thing and does it well. Daemontools is Not Alone By Steve Litt Daemontools is only one of many daemon runners/ available, some of which are built expressly to be run as PID 1. This is a three stage init, with stage 1 for initialize, stage 3 to shut down, and stage 2 to manage everything while running. Daemontools Linux If the ps command reveals no instance of myprogram, it's also probable that svstat /service/myserviced keeps showing the service up for zero or one seconds.
If you were to rename it after that first package/install command, daemontools would silently and mysteriously fail to work. Daemontools Supervise Also, the supervise program allows the root user to control the run script or the program it execs using the svc command, as follows: -u Up Start nonrunning daemon -d Down It might take an added or changed environment variable, or a slight change to the command invoking the program. Steve can be reached at his email address.
Most packages leave it to the user to do the editing. Linux Svc Command OpenRC works with, but doesn't replace, the current /sbin/init. My knowledge is confined to using his programs: daemontools and djbdns. Messing Up Your Original Program As you spend more and more time and energy making diagnostic changes, it gets more probable that one of those diagnostic changes renders your original program
Because daemontools looks for log/run, the logging tool will be supervised as well, ensuring it will always run. http://forum.daemon-tools.cc/f14/device-setup-error-25007-a-4516/ Create the following shellscript, called print_timestamps.sh, in that newly created directory: log=/tmp/junklog.log sleeptime=1 while /bin/true; do mydate=`date +%C%Y%m%d_%H:%M:%S` echo $mydate >> $log echo $mydate sleep $sleeptime done Set the file readable Daemon Tools Stop Service To see the entire list, see http://cr.yp.to/daemontools/svc.html. Daemon Tools Supervise Example During the day, I work on Seevibes, a platform to measure social interactions related to TV shows.
When you're finally pretty sure that dropping all state would probably cause the service to run, do the following steps: cd /service/mydaemond rm -f /service/mydaemond svg -dx . check my blog The following is how you start both the service and its log: svc -t myserviced myserviced/log If you forget the part about the log, the log won't start. Everyone who uses Unix, Linux or *BSD should look at daemontools. Test that assumption every few minutes. Daemontools Multilog
Services are specified by the directory they live in. Steve can be reached at his email address. OpenACS : Forums : OpenACS Q&A : Daemontools disabled error log ... ? this content log Is the Only Hard Coded Directory log is one of the very few "reserved words" in daemontools.
To get a daemontools-provided xterm window without it constantly restarting, use the svc command's "run once" option: svc -o xtermd Your daemontools-provided xterm window provides you a great tool to peer Linux Supervise Djb uses the Unix filesystem as a natural source of hierarchy, for configuration, grouping, and lots of stuff. This is not easy to do reliably.
Reliable restarts. perp by Wayne Marshall, is a daemon runner that's more modern than daemontools. Observe: mkdir /services/somerandomuserservice ed /services/somerandomuserservice/run a #!/bin/sh exec setuidgid somerandomuser somerandomcommand . Supervise Not Running Typically ./run is a shell script.
myprogram runs but either aborts or fails to loop. These include webservers, mail servers, monitoring servers and fastcgi servers. Their priorities seem to be work simply, work reliably, work securely, and then get the hell out of the way. have a peek at these guys A simple and dumb example of /service/carbon/log/run would be: 1 #!/bin/bash 2 PATH=/usr/local/bin:/usr/bin:/bin 3 exec cat > /var/log/carbon.log It's simple because it works: you can tail the file from outside and
Naturally, before running a command from your xtermd service, you should have verified that the program runs properly on a regular terminal in the foreground. cd /service ln -s /scratch/service/xtermd /service/xtermd If everything went right, within five seconds, an xterm window should appear, with your non-root user, available for you to use. If you want to gzip the file on rotation, prepend '!gzip' to the directory and multilog will take care of it. ps ax | grep readproctitle : Although this isn't done to determine existence of a process, reading its output can tell a lot about what happened when the run script tried
daemontools will never replace systemd, or any other init software, because it doesn't natively handle dependencies like "don't start Apache until the DNS server is started". With /service, once you've created your service, it automatically starts within five seconds. The svc command is used to manipulate your daemon, by sending signals to it. This chapter adds logging to the hello service.
If you were to edit the original, and the daemon restarted in the middle of the edit, the half-edited file would almost certainly produce errors: Possibly data-harming errors. Most packages leave it to the user to do the editing. Also, the setuidgid program runs the program as the user and the user's primary group, but it drops the user's auxilliary groups. If only everyone writing free software would follow those guidelines!
Djb's use of a file's name and contents to represent a key->value pair is classic. Certainly it's a good idea to have $HOME set correctly for the user. D. Reliable restarts.
Your hostname is mydesq2. It doesn't have a PID 1 executable. I've never spoken to him. nosh is a simple init system, inspired by daemontools, like most of the rest.
Copyright © 2002, 2003, 2004, Wayne Marshall. Personally, I'm a big fan of the Linux Philosophy, and it's my opinion that djb's software takes the Linux Philosophy where it's never been before. investigate further ps ax | grep myprogram, where myprogram is the program being exec'ed by your run command.