Why is the ENV set correctly in the container by the first Dockerfile but not by the second one?
I have a small script that I want to run every 10 minutes. I dockerized cron and have it call the script (I know that might be a little weird). If I hardcode the env into the script everything works as intended. But I need to pass them in the Dockerfile instead.
This Dockerfile dockerizes the lone script and the ENV is set appropriately.
FROM python:3.10
WORKDIR /app
COPY . /app
ENV c_setting=5
CMD ["python", "script.py"]
Right now the script just calls os.environ[c_setting] and prints it. Like I said, this finds the ENV set in the dockerfile correctly.
This is the cron version of the dockerfile. All it does is call the same script every 10 minutes.
FROM python:3.10
RUN apt-get update && apt-get -y install cron vim
WORKDIR /app
COPY crontab /etc/cron.d/crontab
COPY . /app
ENV c_setting=5
RUN chmod 0644 /etc/cron.d/crontab
RUN /usr/bin/crontab /etc/cron.d/crontab
CMD ["cron", "-f"]
The cron aspect of this works just fine. It hits the KeyError(c_setting) exception at the right time intervals lol.
Why is the ENV set in the first Dockerfile but not in the second?
Something to do with layers and ordering?
script.py for ref
if __name__ == "__main__":
import os
print(os.environ["c_setting"])
crontab for ref
* * * * * cd ../app && /usr/local/bin/python script.py >> script.log 2>>error.log
