Issue
I have a Python script that runs in a virtual environment on boot from a service file on a Raspberry Pi. The service file is shown below:
[Unit]
Description=Starts IEQ sensors
[Service]
ExecStart = /home/pi/bevo_iaq/.venv/bin/python3 -E /home/pi/bevo_iaq/bevobeacon-iaq/main.py
Restart=always
RestartSec=60s
[Install]
WantedBy=bevobeacon.service
The main.py script includes the following lines to access environment variables:
# AWS credentials
AWS_ACCESS_KEY_ID = os.environ['AWS_ACCESS_KEY_ID']
AWS_SECRET_ACCESS_KEY = os.environ['AWS_SECRET_ACCESS_KEY']
BUCKET_NAME = os.environ['BUCKET_NAME']
I export these variables as the last line from /etc/profile:
export AWS_ACCESS_KEY_ID='<aws_access_key>'
export AWS_SECRET_ACCESS_KEY='<aws_secret_access_key>'
export BUCKET_NAME='<bucket_name>'
When the RPi tries to run the script on boot via the service file, I get the following error:
Feb 21 08:43:57 raspberrypi systemd[1]: Started Starts IEQ sensors.
Feb 21 08:43:58 raspberrypi sudo[296]: root : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/home/pi/bevo_iaq/.venv/bin/python3 -E /home/pi/be
Feb 21 08:43:58 raspberrypi sudo[296]: pam_unix(sudo:session): session opened for user root by (uid=0)
Feb 21 08:44:03 raspberrypi sudo[296]: environ({'LANG': 'en_GB.UTF-8', 'PATH': '/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin',
Feb 21 08:44:03 raspberrypi sudo[296]: Traceback (most recent call last):
Feb 21 08:44:03 raspberrypi sudo[296]: File "/home/pi/bevo_iaq/bevobeacon-iaq/main.py", line 213, in <module>
Feb 21 08:44:03 raspberrypi sudo[296]: asyncio.run(main(beacon = beacon))
Feb 21 08:44:03 raspberrypi sudo[296]: File "/usr/lib/python3.7/asyncio/runners.py", line 43, in run
Feb 21 08:44:03 raspberrypi sudo[296]: return loop.run_until_complete(main)
Feb 21 08:44:03 raspberrypi sudo[296]: File "/usr/lib/python3.7/asyncio/base_events.py", line 584, in run_until_complete
Feb 21 08:44:03 raspberrypi sudo[296]: return future.result()
Feb 21 08:44:03 raspberrypi sudo[296]: File "/home/pi/bevo_iaq/bevobeacon-iaq/main.py", line 32, in main
Feb 21 08:44:03 raspberrypi sudo[296]: AWS_ACCESS_KEY_ID = os.environ['AWS_ACCESS_KEY_ID']
Feb 21 08:44:03 raspberrypi sudo[296]: File "/usr/lib/python3.7/os.py", line 678, in __getitem__
Feb 21 08:44:03 raspberrypi sudo[296]: raise KeyError(key) from None
Feb 21 08:44:03 raspberrypi sudo[296]: KeyError: 'AWS_ACCESS_KEY_ID'
However, when I run the script manually, it works with no issues:
pi@raspberrypi:~/bevo_iaq $ source .venv/bin/activate
(.venv) pi@raspberrypi:~/bevo_iaq $ python3 -E bevobeacon-iaq/main.py
.
.
.
/home/pi/DATA/b07_2022-02-21.csv was uploaded to AWS S3 bucket: <bucket_name>
I am not sure what the issue is but it seems like the environment variables are not loaded in correctly when the script runs from boot. I saw from another question that the environment variables are cleared when using sudo which I am not, but I also see from the error log that I am running the script as the root user - perhaps that is the issue?
If you really want to go down the rabbit hole, the entire project can be found here.
Solution
The user instance of systemd does not inherit environment variables set in files such as .bashrc, /etc/profile, etc.
There are several ways to set environment variables for a systemd service, one is to provide them in your service file:
[Unit]
Description=Starts IEQ sensors
[Service]
EnvironmentFile=/lib/systemd/system/myenv.env
ExecStart = /home/pi/bevo_iaq/.venv/bin/python3 -E /home/pi/bevo_iaq/bevobeacon-iaq/main.py
Restart=always
RestartSec=60s
[Install]
WantedBy=bevobeacon.service
In myenv.env:
AWS_ACCESS_KEY_ID=SECRET_1
AWS_SECRET_ACCESS_KEY=SECRET_2
BUCKET_NAME=SECRET_3
See: https://unix.stackexchange.com/a/455283
Answered By - Cubix48 Answer Checked By - Cary Denson (WPSolving Admin)