Modify db docker service to use the env file

[del9ra]

Fixes #309

What changes did you make?

• moved the environment variables from docker-compose.yml file to .env.docker-example
• replaced the environment section with env_file: - ./app/.env.docker-example in docker-compose.yml
• change the django settings (settings.py) code to use the database variable names that the db container uses

Why did you make the changes (we will use this info to test)?

• to update the db Docker container to use the same .env file as the web container, so we avoid hard-coding values in the docker-compose.yml file

[fyliu]

Thanks for working on this!

I slack messaged Ethan about the sqlite. I think we need to wait for his response to determine how to name the env variables. But, ultimately, we want to get rid of the docker-compose.yml variables like you did here.

[del9ra]

1. Almost done
2. Blocker: I changed each SQL affix to POSTGRES under this section: # postgres settings for local development, but I didn’t change anything under # sqlite settings for local development since it’s for SQLite. I only changed the variable names, not the values.
   Do I need to replace the SQL prefix with POSTGRES in the .env.docker file as well?
3. ETA - November 15

[fyliu]

Sorry I wasn't more clear before. I was also not thinking clearly about the scope of this issue. We're just trying to remove the hardcoded lines in the compose file. Since the project had support for sqlite, we should just let it keep doing that and add a workaround to do both. I wrote the details on what to do in the comments.

[fyliu]

I think this is not too obvious to test, but if you copied app/.env.docker-example to app/.env.docker and ran ./scripts/buildrun.sh, it actually doesn't run. I put the reason for that in the comments. Thanks for working through this!

I'm not sure what this refers to, but the code changes look good and is working right now.

[fyliu]

Thanks for contributing these changes! The code looks good and it's running well.