Improve reverse proxy documents and clarify the AppURL guessing behavior (#31003)

Fix #31002

1. Mention Make sure `Host` and `X-Fowarded-Proto` headers are correctly passed to Gitea
2. Clarify the basic requirements and move the "general configuration" to the top
3. Add a comment for the "container registry"
4. Use 1.21 behavior if the reverse proxy is not correctly configured

Co-authored-by: KN4CK3R <admin@oldschoolhack.me>
This commit is contained in:
wxiaoguang 2024-05-19 22:56:08 +08:00 committed by GitHub
parent 58a03e9fad
commit 339bc8bc8f
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5 changed files with 78 additions and 61 deletions

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@ -32,7 +32,7 @@ func IsRelativeURL(s string) bool {
return err == nil && urlIsRelative(s, u)
}
func guessRequestScheme(req *http.Request, def string) string {
func getRequestScheme(req *http.Request) string {
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-Proto
if s := req.Header.Get("X-Forwarded-Proto"); s != "" {
return s
@ -49,10 +49,10 @@ func guessRequestScheme(req *http.Request, def string) string {
if s := req.Header.Get("X-Forwarded-Ssl"); s != "" {
return util.Iif(s == "on", "https", "http")
}
return def
return ""
}
func guessForwardedHost(req *http.Request) string {
func getForwardedHost(req *http.Request) string {
// https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/X-Forwarded-Host
return req.Header.Get("X-Forwarded-Host")
}
@ -63,15 +63,24 @@ func GuessCurrentAppURL(ctx context.Context) string {
if !ok {
return setting.AppURL
}
if host := guessForwardedHost(req); host != "" {
// if it is behind a reverse proxy, use "https" as default scheme in case the site admin forgets to set the correct forwarded-protocol headers
return guessRequestScheme(req, "https") + "://" + host + setting.AppSubURL + "/"
} else if req.Host != "" {
// if it is not behind a reverse proxy, use the scheme from config options, meanwhile use "https" as much as possible
defaultScheme := util.Iif(setting.Protocol == "http", "http", "https")
return guessRequestScheme(req, defaultScheme) + "://" + req.Host + setting.AppSubURL + "/"
// If no scheme provided by reverse proxy, then do not guess the AppURL, use the configured one.
// At the moment, if site admin doesn't configure the proxy headers correctly, then Gitea would guess wrong.
// There are some cases:
// 1. The reverse proxy is configured correctly, it passes "X-Forwarded-Proto/Host" headers. Perfect, Gitea can handle it correctly.
// 2. The reverse proxy is not configured correctly, doesn't pass "X-Forwarded-Proto/Host" headers, eg: only one "proxy_pass http://gitea:3000" in Nginx.
// 3. There is no reverse proxy.
// Without an extra config option, Gitea is impossible to distinguish between case 2 and case 3,
// then case 2 would result in wrong guess like guessed AppURL becomes "http://gitea:3000/", which is not accessible by end users.
// So in the future maybe it should introduce a new config option, to let site admin decide how to guess the AppURL.
reqScheme := getRequestScheme(req)
if reqScheme == "" {
return setting.AppURL
}
return setting.AppURL
reqHost := getForwardedHost(req)
if reqHost == "" {
reqHost = req.Host
}
return reqScheme + "://" + reqHost + setting.AppSubURL + "/"
}
func MakeAbsoluteURL(ctx context.Context, s string) string {