Systemd - Revision history

Hdridder at 18:20, 25 September 2024

2024-09-25T18:20:04Z

@@ Line 7: / Line 7: @@
 The service command invokes a script in /etc/init.d.
 ;service --status-all
 :Run all scripts with the 'status' option. Tells you which services are up.
@@ Line 108: / Line 109: @@
      main()
 </syntaxhighlight>

Hdridder: /* Create a service */

2024-06-05T20:24:58Z

Create a service

← Older revision		Revision as of 20:24, 5 June 2024
Line 67:		Line 67:
	[Unit]		[Unit]
	Description=Test daemon		Description=Test daemon
			After=mnt-www.mount # Start after /mnt/www is mounted

	[Service]		[Service]
	Type=simple		Type=simple
	User=~~hans~~		User=<username> # User dat will run the program
	ExecStart=~~/opt/apo/python~~/daemontest.py		ExecStart=<path to>/daemontest.py
	Restart=on-failure		Restart=on-failure

Hdridder at 20:27, 4 June 2024

2024-06-04T20:27:14Z

← Older revision		Revision as of 20:27, 4 June 2024
Line 60:		Line 60:
	;systemd-analyze [blame\|critical-chain]		;systemd-analyze [blame\|critical-chain]
	:Utility that shows what is holding up the boot process		:Utility that shows what is holding up the boot process


			==Create a service==
			/etc/systemd/system/daemontest.service
			<syntaxhighlight lang=text>
			[Unit]
			Description=Test daemon

			[Service]
			Type=simple
			User=hans
			ExecStart=/opt/apo/python/daemontest.py
			Restart=on-failure

			[Install]
			WantedBy=default.target
			</syntaxhighlight>

			<syntaxhighlight lang=bash>
			systemctl daemon-reload
			systemctl enable daemontest.service
			</syntaxhighlight>

			<syntaxhighlight lang=python>
			#!/usr/bin/env python3

			import daemon
			from time import sleep
			from datetime import datetime

			outfile = '/tmp/testdaemon_{}.out'

			def main():
			count = 5
			while count:
			with open(outfile.format(count),'w') as fh:
			count -= 1
			count2 = 3
			while count2:
			count2 -= 1
			fh.write(f"{datetime.now()} Dit is een test\n")
			sleep(10)


			with daemon.DaemonContext():
			main()
			</syntaxhighlight>

Hdridder at 20:01, 4 January 2023

2023-01-04T20:01:20Z

← Older revision		Revision as of 20:01, 4 January 2023
Line 9:		Line 9:
	;service --status-all		;service --status-all
	:Run all scripts with the 'status' option. Tells you which services are up.		:Run all scripts with the 'status' option. Tells you which services are up.
			;service <service>
			:Show all options for service, usually 'start\|stop\|restart\|reload\|status'
			;service <service> status
			:Show detailed status for <service>
			;systemctl enable <service>
			:Make the service start at boot-time
	;systemctl list-units		;systemctl list-units
	:Show all known units. Alternative for <code>service --status-all</code> that does not work on modern RedHat versions.		:Show all known units. Alternative for <code>service --status-all</code> that does not work on modern RedHat versions.

	;systemctl list-timers		;systemctl list-timers
	:Show all active timers		:Show all active timers
Line 51:		Line 55:
	;systemctl daemon-reload		;systemctl daemon-reload
	:After changing a configuration file reload it		:After changing a configuration file reload it
	;systemctl mask UNIT>		;systemctl mask <UNIT>
	:Link the timer to /dev/null effectively disabling it		:Link the timer to /dev/null effectively disabling it

	;systemd-analyze [blame\|critical-chain]		;systemd-analyze [blame\|critical-chain]
	:Utility that shows what is holding up the boot process		:Utility that shows what is holding up the boot process

Hdridder at 11:33, 17 March 2021

2021-03-17T11:33:51Z

← Older revision		Revision as of 11:33, 17 March 2021
Line 53:		Line 53:
	;systemctl mask UNIT>		;systemctl mask UNIT>
	:Link the timer to /dev/null effectively disabling it		:Link the timer to /dev/null effectively disabling it

			;systemd-analyze [blame\|critical-chain]
			:Utility that shows what is holding up the boot process

Hdridder at 14:02, 27 April 2020

2020-04-27T14:02:34Z

← Older revision		Revision as of 14:02, 27 April 2020
Line 5:		Line 5:
	It also provides timed execution like cron does equally well.		It also provides timed execution like cron does equally well.

	The service command ~~invoke~~ script in /etc/init.d.		The service command invokes a script in /etc/init.d.

	;service --status-all		;service --status-all

Hdridder at 08:02, 17 April 2020

2020-04-17T08:02:47Z

← Older revision		Revision as of 08:02, 17 April 2020
Line 1:		Line 1:
			[[category:Linux/Unix]]

	Replaces initd. It should be more efficient. Honestly I don't see the benefits.		Replaces initd. It should be more efficient. Honestly I don't see the benefits.

Hdridder at 07:42, 17 April 2020

2020-04-17T07:42:37Z

← Older revision		Revision as of 07:42, 17 April 2020
Line 1:		Line 1:
	Replaces initd. It should be more efficient. Honestly I don't see the benefits.		Replaces initd. It should be more efficient. Honestly I don't see the benefits.

			It also provides timed execution like cron does equally well.

	The service command invoke script in /etc/init.d.		The service command invoke script in /etc/init.d.
Line 6:		Line 8:
	:Run all scripts with the 'status' option. Tells you which services are up.		:Run all scripts with the 'status' option. Tells you which services are up.

	~~It also provides timed execution like cron~~ does ~~equally well~~.		;systemctl list-units
			:Show all known units. Alternative for <code>service --status-all</code> that does not work on modern RedHat versions.

	;systemctl list-timers		;systemctl list-timers

Hdridder at 20:25, 19 April 2019

2019-04-19T20:25:37Z

← Older revision		Revision as of 20:25, 19 April 2019
Line 46:		Line 46:
	;systemctl daemon-reload		;systemctl daemon-reload
	:After changing a configuration file reload it		:After changing a configuration file reload it
			;systemctl mask UNIT>
			:Link the timer to /dev/null effectively disabling it

Hdridder: Created page with "Replaces initd. It should be more efficient. Honestly I don't see the benefits. The service command invoke script in /etc/init.d. ;service --status-all :Run all scripts with..."

2018-11-28T21:22:06Z

Created page with "Replaces initd. It should be more efficient. Honestly I don't see the benefits. The service command invoke script in /etc/init.d. ;service --status-all :Run all scripts with..."

New page

Replaces initd. It should be more efficient. Honestly I don't see the benefits.

The service command invoke script in /etc/init.d.

;service --status-all
:Run all scripts with the 'status' option. Tells you which services are up.

It also provides timed execution like cron does equally well.

;systemctl list-timers
:Show all active timers

E.g for [https://letsencrypt.org/ certbot (letsencrypt)]

<syntaxhighlight lang='bash'>
$ systemctl list-timers
NEXT LEFT LAST PASSED UNIT ACTIVATES
do 2018-11-29 00:00:00 CET 2h 5min left wo 2018-11-28 12:00:01 CET 9h ago certbot.timer certbot.service

2 timers listed.
Pass --all to see loaded but inactive timers, too.

$ cat /lib/systemd/system/certbot.timer
[Unit]
Description=Run certbot twice daily

[Timer]
OnCalendar=*-*-* 00,12:00:00
Persistent=true

[Install]
WantedBy=timers.target

$ cat /lib/systemd/system/certbot.service
[Unit]
Description=Certbot
Documentation=file:///usr/share/doc/python-certbot-doc/html/index.html
Documentation=https://letsencrypt.readthedocs.io/en/latest/
[Service]
Type=oneshot
ExecStartPre=/usr/bin/perl -e 'sleep int(rand(3600))'
ExecStart=/usr/bin/certbot -q renew
PrivateTmp=true
</syntaxhighlight>

;systemctl daemon-reload
:After changing a configuration file reload it