Add environment variable support for Docker image

[twang2218]

• Add gettext dependencies as we need envsubst command;
• Modified s6's gitea setup script, instead of cp the template if no
  app.ini exist, it will substitude the envvars and generate the new
  app.ini;
• Make /docker/etc/templates/app.ini a template contains environment
  variables;

The following environment variable can be set:

• APP_NAME: (default: Gitea: Git with a cup of tea)
• APP_MODE: (default: dev)
• [server]:
  • SSH_DOMAIN: (default: localhost)
  • HTTP_PORT: (default: 3000)
  • ROOT_URL: (default: '')
  • DISABLE_SSH: (default: false)
  • SSH_PORT: (default: 22)
• [database]:
  • DB_TYPE: (default: sqlite3)
  • DB_HOST: (default: localhost:3306)
  • DB_NAME: (default: gitea)
  • DB_USER: (default: root)
  • DB_PASSWD: (default: ``)
• [security]:
  • INSTALL_LOCK: (default: true)
  • SECRET_KEY: (default: JPuNRXxX2G)

With these environment variables available, user can easily run the docker image with minor modifications without creating an custom app.ini, such as:

$ docker run -d -p 3000:3000 \
    -e ROOT_URL=http://dev.example.com \
    -e DB_TYPE=mysql \
    -e DB_HOST=1.2.3.4:3306 \
    -e DB_USER=gitea \
    -e DB_PASSWD=Sup3rPassw0rd \
    -e SECRET_KEY=Sup3r3ecre7 \
    gitea/gitea:latest

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

[sapk]

This need rebase. This is good to be configurated by env var but

We shoudn't use a default SECRET_KEY.

I think that we shoud only set INSTALL_LOCK to true only if SECRET_KEY set by user otherwise we should display the /install page.

[twang2218]

@sapk Good point, I updated the PR, only set INSTALL_LOCK to true if SECRET_KEY is not empty, and INSTALL_LOCK is empty. And the default SECRET_KEY is removed.

[vtemian]

Thanks for this PR!

[vtemian]

Small typo: environment

[twang2218]

fixed.

[vtemian]

This is pretty obvious from the instruction itself.
Maybe a more useful comment would by why it's needed to set INSTALL_LOCK to true.

[twang2218]

This is a good question, why it's needed?

It was obviously that we alway go through the installation process to setup the SECRET_KEY. However, why we have to?

I didn't find any document clear the relationship between INSTALL_LOCK and SECRET_KEY, so I read the code, and I found the SECRET_KEY will be randomly generated ONLY during the installation:

gitea/routers/install.go

Lines 315 to 320 in 2c3a229

	var secretKey string
	if secretKey, err = base.GetRandomString(10); err != nil {
	ctx.RenderWithErr(ctx.Tr("install.secret_key_failed", err), tplInstall, &form)
	return
	}
	cfg.Section("security").Key("SECRET_KEY").SetValue(secretKey)

	var secretKey string
	if secretKey, err = base.GetRandomString(10); err != nil {
		ctx.RenderWithErr(ctx.Tr("install.secret_key_failed", err), tplInstall, &form)
		return
	}
	cfg.Section("security").Key("SECRET_KEY").SetValue(secretKey)

Otherwise, it will try to find the user setting SECRET_KEY first, and if user is not providing the value, it will use the default string !#@FDEWREWR&*(, which is not safe and should be random generated.

gitea/modules/setting/setting.go

Line 813 in ced50e0

SecretKey = sec.Key("SECRET_KEY").MustString("!#@FDEWREWR&*(")

	SecretKey = sec.Key("SECRET_KEY").MustString("!#@FDEWREWR&*(")

ping @sapk and @lunny , could you tell me why the default value for the SECRET_KEY is a static value, instead of a randomly generated key?

I read the issue #455 , I'm still not clear. I think the SECRET_KEY should always be generated if the value is not provided by the user, the static default string should be avoided in this case.

[lunny]

@twang2218 It should be.

[lafriks]

LGTM

[lunny]

LGTM

[codecov-io]

Codecov Report

Merging #2201 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #2201   +/-   ##
=======================================
  Coverage   26.85%   26.85%           
=======================================
  Files          89       89           
  Lines       17600    17600           
=======================================
  Hits         4727     4727           
  Misses      12187    12187           
  Partials      686      686

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