Add support for getting password from file

[kazan417]

Add support for getting password from file.
This is good feature for using docker secrets

[wxiaoguang]

Docker supports env_file: https://docs.docker.com/compose/how-tos/environment-variables/set-environment-variables/#use-the-env_file-attribute , https://docs.docker.com/compose/how-tos/environment-variables/variable-interpolation/#env-file

Does it work for you?

[wxiaoguang]

And Gitea has general "file to env" suppport in "environment-to-ini" https://github.com/go-gitea/gitea/blob/main/contrib/environment-to-ini/environment-to-ini.go

	Environment variables of the form "GITEA__SECTION_NAME__KEY_NAME__FILE"
	will be mapped to the ini section "[section_name]" and the key
	"KEY_NAME" with the value loaded from the specified file.

It is also packed into the docker image. So I think it doesn't need to add a new environment here?

gitea/docker/root/etc/s6/gitea/setup

Line 60 in df9a78c

environment-to-ini --config ${GITEA_CUSTOM}/conf/app.ini

[silverwind]

Suggested change

	DB_PASSWD=`cat $DB_PASSWD_FILE`;
	DB_PASSWD="$(cat $DB_PASSWD_FILE)";

backtick syntax is legacy.

[wxiaoguang]

Before making more changes, I would suggest to use existing mechanisms. See my comments above.

[silverwind]

Yeah I guess there are better solutions than to introduce _FILE variables for every variable.

[kazan417]

supports env_file: https://docs.docker.com/compose/how-tos/environment-variables/set-environment-variables/#use-the-env_file-attribute , https://docs.docker.com/compose/how-tos/environment-variables/variable-interpolation/#env-file

Does it work for

No this not work for swarm mode

[kazan417]

And Gitea has general "file to env" suppport in "environment-to-ini" https://github.com/go-gitea/gitea/blob/main/contrib/environment-to-ini/environment-to-ini.go

	Environment variables of the form "GITEA__SECTION_NAME__KEY_NAME__FILE"
	will be mapped to the ini section "[section_name]" and the key
	"KEY_NAME" with the value loaded from the specified file.

It is also packed into the docker image. So I think it doesn't need to add a new environment here?

gitea/docker/root/etc/s6/gitea/setup

Line 60 in df9a78c

environment-to-ini --config ${GITEA_CUSTOM}/conf/app.ini

Thats what i am looking for, but there is no such example in wiki. We need to add it into wiki exemple