Use sqlite3 database as default for Docker image

[twang2218]

The app.ini template file in the Docker image is currently using mysql as default database engine. However, it's not practical as default. Because,

1. It require more setup to run gitea, such as:
   • run a mysql instance inside docker, which has to be named as mysql,
   • prepare a database called gitea,
   • and the password of the mysql's root user has to be empty.
2. People, who are going to use mysql as the database, are more likely provide their own app.ini file, to specify the server address, mysql IP/name, reasonable user & password, etc.

So, my suggestion is that replacing the mysql with sqlite3 as default. So, anyone who just want to simply run the gitea image to get an idea, can just run the image without providing a customized app.ini file or preparing a MySQL server.

Signed-off-by: Tao Wang twang2218@gmail.com

[sapk]

LGTM

[sapk]

This will display by default sqlite3 on /install page if I am not mistaken.

[twang2218]

Yes, the default database type is SQLite3 on the install page:

User still need to go through the install process to get a running server though. My another PR #2201 goes one step further, with environment variable, user can run the gitea docker image with some customization abilities, but without necessary go through the install process, and without the necessary given the app.ini file.

[lunny]

LGTM

[lunny]

make L-G-T-M work