Add redirect capability to sign_out (#314)

* addint redirect capability to sign_out

* updating changelog

CHANGELOG.md

@@ -15,6 +15,7 @@
 - [#300](https://github.com/pusher/oauth2_proxy/pull/300) Added userinfo endpoint (@kbabuadze)
 - [#309](https://github.com/pusher/oauth2_proxy/pull/309) Added support for custom CA when connecting to Redis cache (@lleszczu)
 - [#248](https://github.com/pusher/oauth2_proxy/pull/248) Fix issue with X-Auth-Request-Redirect header being ignored (@webnard)
+- [#314](https://github.com/pusher/oauth2_proxy/pull/314) Add redirect capability to sign_out (@costelmoraru)
 - [#265](https://github.com/pusher/oauth2_proxy/pull/265) Add upstream with static response (@cgroschupp)
 
 # v4.0.0

oauthproxy.go

@@ -620,8 +620,14 @@ func (p *OAuthProxy) UserInfo(rw http.ResponseWriter, req *http.Request) {
 
 // SignOut sends a response to clear the authentication cookie
 func (p *OAuthProxy) SignOut(rw http.ResponseWriter, req *http.Request) {
+	redirect, err := p.GetRedirect(req)
+	if err != nil {
+		logger.Printf("Error obtaining redirect: %s", err.Error())
+		p.ErrorPage(rw, 500, "Internal Error", err.Error())
+		return
+	}
 	p.ClearSessionCookie(rw, req)
-	http.Redirect(rw, req, "/", 302)
+	http.Redirect(rw, req, redirect, 302)
 }
 
 // OAuthStart starts the OAuth2 authentication flow