Allow nextcloud to create the postgres db

[tilosp]

Fixes#345
Closes#516

[J0WI]

Let's wait a few days for nextcloud/server#15187 and nextcloud/server#16064.

postgres has superuser privileges. NextCloud should use the oc_ prefixed user:
https://github.com/nextcloud/server/blob/3f9cdeeb5fe9aee97e410ec59bbdd1c9cf3c33d5/lib/private/Setup/PostgreSQL.php#L62-L71
https://github.com/docker-library/official-images/blob/master/test/tests/nextcloud-cli-postgres/run.sh#L15

[tilosp]

Let's wait a few days for nextcloud/server#15187 and nextcloud/server#16064.

sure let's wait for the rc

postgres has superuser privileges. NextCloud should use the oc_ prefixed user:

It already does so with this pr, nextcloud automatically creates a user oc_test.

[lukasmrtvy]

What should be fixed?

docker run -d \
--name nextcloud-postgres \
--network nexcloud-network \
--restart=unless-stopped \
-e POSTGRES_DB=nextcloud \
-e POSTGRES_PASSWORD=nextcloud \
-e POSTGRES_USER=nextcloud \
-e TZ=Europe/Prague \
postgres:11-alpine
docker run -d \
--name nextcloud \
--network nexcloud-network \
--restart=unless-stopped \
-e POSTGRES_DB=nextcloud \
-e POSTGRES_HOST=nextcloud-postgres \
-e POSTGRES_PASSWORD=nextcloud \
-e POSTGRES_USER=nextcloud \
-e NEXTCLOUD_ADMIN_PASSWORD=admin \
-e NEXTCLOUD_ADMIN_USER=admin \
-e NEXTCLOUD_TRUSTED_DOMAINS=nextcloud.example.com \
nextcloud:16.0.3-apache 

Nextcloud log:

retrying install...
Error while trying to create admin user: Failed to connect to the database: An exception occurred in driver: SQLSTATE[08006] [7] FATAL: permission denied for database "nextcloud"
DETAIL: User does not have CONNECT privilege.
-> retrying install...
Error while trying to create admin user: Failed to connect to the database: An exception occurred in driver: SQLSTATE[08006] [7] FATAL: permission denied for database "nextcloud"
DETAIL: User does not have CONNECT privilege.
-> retrying install...
Error while trying to create admin user: Failed to connect to the database: An exception occurred in driver: SQLSTATE[08006] [7] FATAL: permission denied for database "nextcloud"
DETAIL: User does not have CONNECT privilege.
-> installing of nextcloud failed!

Its not possible to use POSTGRES_USER other than postgres ?

EDIT: Nvm,
maybe there is problem not with #784, but nextcloud/server#15187