Allow pg_cron to work on any configured POSTGRES_DB

[stig]

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Description

This fixes ownership of the files in the /etc/postgresql directory, so the pg_cron.sh script can amend these files as it expects to do.

Reasons

Due to incorrect ownership of /etc/postgresql/custom-postgresql.conf the pg_cron.sh script was not able to add POSTGRES_DB to the cron.database_name config. Thus the only DB that would work with pg_cron is the 'circle_test' DB, as this was hard-coded in the example file.

This fixes ownership of the files in the /etc/postgresql directory, so the pg_cron.sh script can run without errors.

Checklist

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• [x] I have made changes to the Dockerfile.template file only
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[JalexChen]

i think this 'works', but because pg_cron.sh is still running and appending to the custom-postgresql.conf. even if you can now edit the file, the initial value of cron.database_name = circle_test would still be there, and i believe pg_cron can only run one instance.

you can run jobs in a separate database with some tinkering, but i think the play would be either:

1) the custom-postgresql.conf database_name value is set to $POSTGRES_DB, and the env is defined in the docker run command to e.g docker run -it -e POSTGRES_DB=something cimg/postgres:xxx

2) a separate env file that can be modified from defaults, sourced, then used

[stig]

i think this 'works', but because pg_cron.sh is still running and appending to the custom-postgresql.conf. even if you can now edit the file, the initial value of cron.database_name = circle_test would still be there, and i believe pg_cron can only run one instance.

you can run jobs in a separate database with some tinkering, but i think the play would be either:

1. the custom-postgresql.conf database_name value is set to $POSTGRES_DB, and the env is defined in the docker run command to e.g docker run -it -e POSTGRES_DB=something cimg/postgres:xxx
2. a separate env file that can be modified from defaults, sourced, then used

We had a brief chat, and decided that (even though the last setting wins) the best course of action would be to remove the two settings pg_cron.sh adds from the custom-postgresql.conf settings so there is no ambiguity.