From 6d0d07a55b0adf1de199cc1fcdf593786c7f6b27 Mon Sep 17 00:00:00 2001
From: Nick Triller <NickTriller@gmail.com>
Date: Mon, 28 May 2018 16:15:31 +0200
Subject: [PATCH 1/2] Document oauth_auto_login setting

---
 docs/sources/auth/overview.md | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/docs/sources/auth/overview.md b/docs/sources/auth/overview.md
index a372600ac46..d4360d554c1 100644
--- a/docs/sources/auth/overview.md
+++ b/docs/sources/auth/overview.md
@@ -73,7 +73,18 @@ You can hide the Grafana login form using the below configuration settings.
 
 ```bash
 [auth]
-disable_login_form ⁼ true
+disable_login_form = true
+```
+
+### Automatic OAuth login
+
+Set to true to attempt login with OAuth automatically, skipping the login screen. 
+This setting is ignored if multiple OAuth providers are configured. 
+Defaults to `false`.
+
+```bash
+[auth]
+oauth_auto_login = true
 ```
 
 ### Hide sign-out menu

From 3414be18bc46167f7493d12360327d2c5477f1c4 Mon Sep 17 00:00:00 2001
From: Nick Triller <NickTriller@gmail.com>
Date: Mon, 28 May 2018 16:16:48 +0200
Subject: [PATCH 2/2] Implement oauth_auto_login setting

Redirect in backend
---
 pkg/api/login.go       | 22 ++++++++++++++++++++++
 pkg/setting/setting.go |  2 ++
 2 files changed, 24 insertions(+)

diff --git a/pkg/api/login.go b/pkg/api/login.go
index 1083f89adfd..05afc40e59a 100644
--- a/pkg/api/login.go
+++ b/pkg/api/login.go
@@ -39,6 +39,10 @@ func (hs *HTTPServer) LoginView(c *m.ReqContext) {
 		viewData.Settings["loginError"] = loginError
 	}
 
+	if tryOAuthAutoLogin(c) {
+		return
+	}
+
 	if !tryLoginUsingRememberCookie(c) {
 		c.HTML(200, ViewIndex, viewData)
 		return
@@ -53,6 +57,24 @@ func (hs *HTTPServer) LoginView(c *m.ReqContext) {
 	c.Redirect(setting.AppSubUrl + "/")
 }
 
+func tryOAuthAutoLogin(c *m.ReqContext) bool {
+	if !setting.OAuthAutoLogin {
+		return false
+	}
+	oauthInfos := setting.OAuthService.OAuthInfos
+	if len(oauthInfos) != 1 {
+		log.Warn("Skipping OAuth auto login because multiple OAuth providers are configured.")
+		return false
+	}
+	for key := range setting.OAuthService.OAuthInfos {
+		redirectUrl := setting.AppSubUrl + "/login/" + key
+		log.Info("OAuth auto login enabled. Redirecting to " + redirectUrl)
+		c.Redirect(redirectUrl, 307)
+		return true
+	}
+	return false
+}
+
 func tryLoginUsingRememberCookie(c *m.ReqContext) bool {
 	// Check auto-login.
 	uname := c.GetCookie(setting.CookieUserName)
diff --git a/pkg/setting/setting.go b/pkg/setting/setting.go
index 58901e55c6b..7543d91c463 100644
--- a/pkg/setting/setting.go
+++ b/pkg/setting/setting.go
@@ -108,6 +108,7 @@ var (
 	ExternalUserMngLinkUrl  string
 	ExternalUserMngLinkName string
 	ExternalUserMngInfo     string
+	OAuthAutoLogin          bool
 	ViewersCanEdit          bool
 
 	// Http auth
@@ -622,6 +623,7 @@ func (cfg *Cfg) Load(args *CommandLineArgs) error {
 	auth := iniFile.Section("auth")
 	DisableLoginForm = auth.Key("disable_login_form").MustBool(false)
 	DisableSignoutMenu = auth.Key("disable_signout_menu").MustBool(false)
+	OAuthAutoLogin = auth.Key("oauth_auto_login").MustBool(false)
 	SignoutRedirectUrl = auth.Key("signout_redirect_url").String()
 
 	// anonymous access