How do I start a cron service on a web server programatically? - linux

Question

I have been stuck on this for a while and this is new territory for me so I need some help. I am working on a project where a cron service is created when a user is created with a web application. However, I am running into problems actually getting the cron service to run. Here is what I have tried
1) Creating a cron service using
crontab -l | { cat; echo "'comand'"; } | crontab -
This creates the job fine. However, it creates it with www-data as the user and those do not show to execute.
I should mention that I am setting path to
PATH=/usr/local/bin:/usr/bin:/usr/local/sbin:/usr/sbin
as I am running a python script that I have made executable using chmod +x and put the appropriate headers to make sure it runs properly (which it does). In addition, all paths are full paths. To be more clear, here is the actual command I am using inside the crontab
*/10 * * * * /home/user/path-to script/script.py --user_id 1 --db_file /home/user/path-to-file/file.db
However, the script never runs.
2) Creating a file under /etc/cron.d, but from my testing, I have realized that this only works if the file is created as a root user, which since the user creating the file is www-data, the job will again, not execute.
for reference, I am doing that as such:
*/10 * * * * user /home/user/path-to script/script.py --user_id 1 --db_file /home/user/path-to-file/file.db
What does work is repeating steps 2 & 3 using a user that is part of the sudo group or is the root user. This tells me that I need to create the cron job using one of those two users, but I am not sure how to do that programmatically when www-data is being used for web activities.
Another option I have considered is using crontab -u user to programmatically add the job to a user I know works, but the issue with that is that in order to do that I need sudo access and I don't want to pass in the sudo password when creating the cronjob or do something that might be potentially dangerous (like removing the need to use sudo as I know that is possible, but in my opinion could be very bad is someone gains access to the account and therefore has escalated privileges)
Help would really be appreciated.
As for the stack, if it's helpful, I am using Ubuntu 18.04.3 (LTS) x64 and Apacahe2