I am trying to pass an environment variable defined in the current shell to one of the systemd
unit I am writing.
DB_URL=databus.dev.mysite.io:8080
I am using this in a python script which is running as a service. My systemd
unit will run this script as a unit making use of the variable for its working.
[Unit]
Description=device-CompStatus: Computes device availability status
[Service]
Type=simple
ExecStart=/usr/bin/bash -c "/usr/bin/python /opt/deviceCompStatus/deviceCompStatusHandler.py"
Restart=always
[Install]
WantedBy=default.target
The way am using the variable in Python script would be
if os.environ.get('DB_URL') is not None:
dbEndPoint = "http://" + os.environ['DB_URL']
The problem is am not able to use the variable when running the script in systemd
. I looked up couple of resources Using environment variables in systemd units, it says to use assignment under [Service]
directly as
[Service]
Environment=DB_URL=databus.dev.mysite.io:8080
As you can see, my DB_URL
could change depending upon the environment I am deploying my machine, it could be a developer, or a production setup, in which the URLs would vary.
How do I do this dynamically? i.e. pass whatever value available to DB_URL
to systemd
environment?
I also tried using the EnvironmentFile=
option to define a file and pass it to service. But the same problem again, my variable could be dynamic and cannot be hardcoded.
Update
After using the option
systemctl import-environment DB_URL
I am able to see the variable available in the environment of systemd
which I confirmed by
systemctl show-environment
DB_URL=databus.dev.mysite.io:8080
LANG=en_US.UTF-8
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin
but still the value is not reflected in the python
application which I run. Is os.environ('DB_URL')
a wrong way to access the variable?