How do we get my UNIT(service) name in unit.sevice

Boobalan M · 01-23-2018, 01:22 AM

I have small design where i need to get unit name inside my servcie script.

For eg:

Below is my service script,

sample.service

[Unit]
Description=job

[Service]
Type=simple
User=root
Type=forking
ExecStart='{here i need service name}'
Restart=always

When start using 'systemctl start sample' i need to get 'sample' inside my 'sample.service' script.

Is this feasible?

ferrari · 01-23-2018, 01:57 AM

Welcome to LinuxQuestions.org Boobalan M!

I'm not sure I follow you, but I do note that you have two 'Type=' directives. You need to be clear about which type you're after. The 'ExecStart=' entry must consist of one command (eg path to an executable shell script).

A typical example might look like this...

Code:

[Unit]
Description=My custom service
After=network.target

[Service]
Type=simple
User=root
WorkingDirectory=/path/to/
ExecStart=/path/to/my_daemon --option=123
Restart=always

[Install]
WantedBy=multi-user.target

Some simple how to's to give a basic idea...
https://www.digitalocean.com/communi...and-unit-files
http://patrakov.blogspot.co.nz/2011/...ice-files.html

Reference:
http://patrakov.blogspot.co.nz/2011/...ice-files.html

Boobalan M · 01-23-2018, 02:08 AM

Hi ferrari,

Thanks for response.

Actual implementation is, i have the case where my executable will be installed in different directory. Let's say executable is "MyExe" and installed in "mypath"

I will be creating on service script like below and i will keep service name like "MyExe.script",

[Unit]
Description=PLIN_SSP_01

[Service]
Type=simple
User=root
Type=forking
Environment="install_dir=mypath"
ExecStart=${install_dir}/{Here i need service script name}'
Restart=always

In this way, always executable and script name will always remains same.

Please give your input on this if this is achievable?

Regards,
Boobalan M

ferrari · 01-23-2018, 02:27 AM

Sorry, I'm still not grasping what you're tying to achieve here. Hopefully others can.

Boobalan M · 01-23-2018, 02:52 AM

Actual query is, my intention is not configure executable name inside script also. Instead, when ever i run "systemctl start MyExe" script should detect that "MyExe" the is executable to be executed(from install directory).

We do not wanted to configure executable inside script also instead will expose like executable and script name are same.

Hope this makes clear.

ferrari · 01-23-2018, 03:17 AM

Now I think I understand

I think what you're after are template unit files in the form <service_name>@<script_name>.service, whereby service instances can be created dynamically as needed. Such a template service could be constructed such that a script called <script_name> can be executed when the given service instance is started.

Described here...
http://0pointer.de/blog/projects/instances.html
https://fedoramagazine.org/systemd-template-unit-files/

Boobalan M · 01-23-2018, 05:03 AM

Not exactly this way i was expecting as i could see that here we need to make our script naming convention like "MyExe@MyExe.service" instead "MyExe.service". Any i will go forward with this option.

Also i could see that, i couldnt use env variable in "WorkingDirectory" inside script.

Environment="INSTALL_DIR=/opt/product/mypath"

WorkingDirectory=${INSTALL_DIR}/bin

I could see that path expansion not working in WorkingDirectory. Is there any way?