Systemd, Debian and former cron jobs

[drmike]

So I am late to the systemd circus. 

Updated a Debian box today with cronjobs that need to fire.

This new systemd appears to make cronjobs no longer run.  Been depreciated and such should be in systemd mess.

Can someone point me to some how-tos or  simple instruction on where stuff formerly we poked in crontab should now go?

Noticed a slew of scheduled jobs didn't run today and need to fix those and clean up backlog.

 

[InertiaNetworks-Ryan]

Here you go Buffa - https://wiki.archlinux.org/index.php/Systemd/Timers

If you want a straight up conversion then checkout the repo https://github.com/kstep/systemd-crontab-generator

 

[Amitz]

This is just another of many reasons why systemd is such a pain and utter mistake... :-(

 

[drmike]

I read the Arch doc earlier and still am going huh big picture.

Going to be a lot of normal folks who when they upgrade run into this problem and determine it after the fact.

We need a better doc for humans to take their nice and straightforward crontab entries and get them converted into Systemd version.

PS: I am not anti-change - systemd has benefits surely.  But complicating cron like this and in upgrade process not addressing scheduled jobs for folks was a BIG MISTAKE by Debian devs.

 

[InertiaNetworks-Ryan]

I see Buffa. I run Arch Linux on my desktop full time so I'm use to systemd. I like how in systemd's timer mechanism everything is just written out in plain english and it just works. With cron that was a different story depending on the program or script interpreter. I also didn't like the @reboot hack in cron since a service can be made if its really important for a process to run on startup and die at reboot/shutdown.

If you want you can PM/Skype me your crontab config and I'll convert it for ya.

 

[drmike]

I see Buffa. I run Arch Linux on my desktop full time so I'm use to systemd. I like how in systemd's timer mechanism everything is just written out in plain english and it just works. With cron that was a different story depending on the program or script interpreter. I also didn't like the @reboot hack in cron since a service can be made if its really important for a process to run on startup and die at reboot/shutdown.

If you want you can PM/Skype me your crontab config and I'll convert it for ya.

Much appreciated.   This is Debian so likely different paths and all that fun.

Maybe we should do some samples for benefit of everyone else out there.  Legit pain for a lot of folks with no tech tolerance or ability to Google the solution (results to queries in Google even Debian specific are Arch results ) === BAD.

Let's take example of just a standard crontab scheduled job.  This is a recorder for a gardening show.


0 6 * * 7 /home/recorder http://gcnplayer.gcnlive.com:80/channel3-hi.mp3 paulparent /home/recorder/ 14400

Runs on Sunday morning at 6AM a script called recorder that is just fronting streamripper in this instance and records the show for 14400 seconds.

How does one take that literal cron entry and get that converted into Systemd's timers --- emphasis on Debian?

PS: Arch keeps taunting me.  Have ArchBang on my shortlist -  long time fan of CrunchBang which went to no more dev.

 

[InertiaNetworks-Ryan]

NOTE... This will make this cronjob/systemd service run as root. If you want it to run as a specified user, you must change the service file name to the following "cron-radiorecorder@(user).service", (user) meaning your account name. You must also update the timer file to reflect the new file name.

 

Make a filed called /etc/systemd/system/cron-radiorecorder.service



[Unit]
Description=Buffas Radio Recorder Service
# The name of the timer that's going to call this service file.
Wants=cron-radiorecorder.timer

[Service]
# Comment out the line below if you want to run it as root.
User=%I
# KISS (Keep It Simple Stupid)
Type=simple
# The actual command that must be called.
ExecStart=/home/recorder http://gcnplayer.gcnlive.com:80/channel3-hi.mp3 paulparent /home/recorder/ 14400

[Install]
WantedBy=basic.target


 


Next make the file called /etc/systemd/system/cron-radiorecorder.timer


[Unit]
Description=Buffas Radio Recorder Job

[Timer]
# To add a time of your choosing here, please refer to systemd.time manual page for the correct format
OnCalendar=Sun *-*-* 06:00:00
# Persistence=true since this script is going to be called every week for life.
Persistent=true
# The name of the actual service must be specified since it contains the command to be run.
Unit=cron-radiorecorder.service

[Install]
WantedBy=basic.target


Now to install and enable it...



# Refresh the daemons that systemd can see.
systemctl daemon-reload
# Enable the cron-radiorecorder timer
systemctl enable cron-radiorecorder.timer
# Enable the cron-radiorecorder service
systemctl enable cron-radiorecorder.service
# Start the cron-radiorecorder timer
systemctl start cron-radiorecorder.timer



And that's all folks!

Since the service is created in systemd, the service can be started or stopped at any time by using "systemctl (start/stop) cron-radiorecorder.service". The cronjob/timer can be enabled/disabled and start/stopped doing "systemctl (enable/disable/start/stop) cron-radiorecorder.timer".

Hopefully this will be able to help you.

 

[drmike]

I'm grateful for the time and effort Mr. Ryan.  Quite a bunch of additional effort for what use to be a very simple cronjob.

I'll give systemd a try on local workstation.  I already purged it from remote VPS instance and went back to cron and none systemd.  Since I had broken stuff...  and not thrilled.

 

[drmike]

There is this doc to remove systemd that worked for me:

http://without-systemd.org/wiki/index.php/How_to_remove_systemd_from_a_Debian_jessie/sid_installation

List of OS options with systemd here:

http://without-systemd.org/wiki/index.php/Main_Page

 

[raindog308]

PS: I am not anti-change - systemd has benefits surely.

Name one.

I didn't know cron was "deprecated".  Works fine in CentOS 7 out of the box and RHEL/CentOS is the home/breeding ground of systemd.