Systemd with Multiple Execstart

Systemd with multiple execStart

if Type=simple in your unit file, you can only specify one ExecStart, but you can add as many ExecStartPre, ExecStartPost, but none of this is suited for long running commands, because they are executed serially and everything one start is killed before starting the next one.

If Type=oneshot you can specify multiple ExecStart, they run serially not in parallel.

If what you want is to run multiple units in parallel, there a few things you can do:

If they differ on 1 param

You can use template units, so you create a /etc/systemd/system/foo@.service. NOTE: (the @ is important).

[Unit]
Description=script description %I

[Service]
Type=simple
ExecStart=/script.py %i
Restart=on-failure

[Install]
WantedBy=multi-user.target

And then you exec:

$ systemctl start foo@parameter1.service foo@parameter2.service

or...

Target dependencies

You can create multiple units that links to a single target:

#/etc/systemd/system/bar.target
[Unit]
Description=bar target
Requires=multi-user.target
After=multi-user.target
AllowIsolate=yes

And then you just modify you .service units to be WantedBy=bar.target like:

#/etc/systemd/system/foo@.service
[Unit]
Description=script description %I

[Service]
Type=simple
ExecStart=/script.py %i
Restart=on-failure

[Install]
WantedBy=bar.target

Then you just enable the foo services you want in parallel, and start the bar target like this:

$ systemctl daemon-reload
$ systemctl enable foo@param1.service
$ systemctl enable foo@param2.service
$ systemctl start bar.target

NOTE: that this works with any type of units not only template units.

Execute multiple commands with && in systemd service ExecStart on RedHat 7.9

The command line is not given to a shell, so && is not valid. You would need, for example,

ExecStart=/bin/bash -c 'sleep 45 && /bin/bash bin/eum.sh start'

or you could separate the commands into

ExecStartPre=/usr/bin/sleep 45
ExecStart=/bin/bash bin/eum.sh start

Systemd service with multiple execStart and watchdog for each execStart

I found that using the template service is the better solution and covers what I need. Thanks to you all.

How to execute multiple command in ExecStart

A separate script is a possible solution, as Charles wrote, or you can run the command with bash -c or sh -c, like this:

/bin/bash -c '/bin/tar -zcvf "/var/log/test/$(/bin/date)_syslog_archive.tar.gz" "/tmp/log/"'

As an aside, you probably want a + parameter of the date command, like date +%s or date +%Y%m%d so that you get something that is suitable for a filename, making it something like this:

/bin/bash -c '/bin/tar -zcvf "/var/log/test/$(/bin/date +%s)_syslog_archive.tar.gz" "/tmp/log/"'

How to run multiple command systemd

You can start multiple background processes from one systemd unit, but systemd will not be able to track them for you and do all the nice things that it does to support a daemon, such as send signals to it on various system events or auto-restart it when needed.

If you must have it as a single unit, then you can do one of the following (in my order of preference):

• make the two servers separate units (note you may be able to use the same config file for both, so they are two 'instances' of the same service - which makes sense, they run the same server). You will have two entries in the list of running services when you run 'systemctl'.

• make that unit a one-shot (runs a program that exits and is not monitored and restarted). Make the one-shot command start both servers in background, e.g.,

  sh -c " { pserve production.ini http_port=5000 & pserve production.ini http_port=5001 & } </dev/null >/dev/null >&1"

• make a script that launches both daemons and watches for them, restarting them if needed and kills them when it is killed itself. Then you make that script the 'daemon' that systemd runs. Not really worth it, IMO - because you're doing much of the work that systemd itself is best suited to do. Of course you can spin a new copy of systemd that is configured to run just those two servers (and make that systemd as your 'one-service-for-two-commands' unit), but that seems an overkill.

Executing multiple Python scripts in a particular order using systemd

What you need are 2 different systemd unit and define the dependency using requires

[Unit]
Description=My script

[Service]
ExecStart=/usr/bin/python3 /home/pi/Desktop/myscript.py
Requires=dhangioserver.service 

[Install]
WantedBy=multi-user.target

It will also be good to specify RequiredBy in DjangoService unit

There is a related spec called Wants which differs only in whether service should continue if dependendcy fails or not. Looking at your requirement , it looks like you need Requires and not Wants

systemd : two services are running together

The main process (PID 1625) is most probably forking another process (PID 1627).
To check that the parent process of 1627 is 1625: ps -o ppid 1627

How to run multiple ExecStart in kafka.service for Multiple brokers in Kafka?

You cannot. You could use multiple systemd scripts that depend on each other or wrap all three in one command (for example, docker-compose -f kafka-cluster.yaml up)

FWIW, in no way is this fault tolerant, or really a good idea unless you have at least 18G memory (giving 6G RAM each) and at least a factor of 3 available mechanical HDDs on that machine (three or more pools of JBOD for log.dirs) and at least 3 separate CPU.

Note: ExecStop is also only stopping one of the broker processes

Systemctl starting multiple commands

First, you need to fix [service] to [Service]. That is a syntax error. Second, you need to fix %i to %f. systemd escapes / in instance name to -. %f can get unescaped instance name.

More detail.

• https://www.freedesktop.org/software/systemd/man/systemd.unit.html#String%20Escaping%20for%20Inclusion%20in%20Unit%20Names
• https://www.freedesktop.org/software/systemd/man/systemd.unit.html#Specifiers

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