Additional OAuth2 providers (#1010)

* add google+

* sort signin oauth2 providers based on the name so order is always the same

* update auth tip for google+

* add gitlab provider

* add bitbucket provider (and some go fmt)

* add twitter provider

* add facebook provider

* add dropbox provider

* add openid connect provider incl. new format of tips section in "Add New Source"

* lower the amount of disk storage for each session to prevent issues while building cross platform (and disk overflow)

* imports according to goimport and code style

* make it possible to set custom urls to gitlab and github provider (only these could have a different host)

* split up oauth2 into multiple files

* small typo in comment

* fix indention

* fix indentation

* fix new line before external import

* fix layout of signin part

* update "broken" dependency

11 files changed, 67 insertions, 5 deletions

diff --git a/public/css/index.css b/public/css/index.css
index b0fc396cca..3fa2d6d0fd 100644
--- a/public/css/index.css
+++ b/public/css/index.css
@@ -965,7 +965,7 @@ footer .ui.language .menu {
   float: left;
 }
 .signin .oauth2 a {
-  margin-right: 5px;
+  margin-right: 3px;
 }
 .signin .oauth2 a:last-child {
   margin-right: 0px;
@@ -974,6 +974,9 @@ footer .ui.language .menu {
   width: 32px;
   height: 32px;
 }
+.signin .oauth2 img.openidConnect {
+  width: auto;
+}
 .user.activate form,
 .user.forgot.password form,
 .user.reset.password form,
diff --git a/public/img/auth/bitbucket.png b/public/img/auth/bitbucket.png
new file mode 100644
index 0000000000..b3d022a5a7
--- /dev/null
+++ b/public/img/auth/bitbucket.png
diff --git a/public/img/auth/dropbox.png b/public/img/auth/dropbox.png
new file mode 100644
index 0000000000..da2348872a
--- /dev/null
+++ b/public/img/auth/dropbox.png
diff --git a/public/img/auth/facebook.png b/public/img/auth/facebook.png
new file mode 100644
index 0000000000..29273af14f
--- /dev/null
+++ b/public/img/auth/facebook.png
diff --git a/public/img/github.png b/public/img/auth/github.png
index 1fa19c55d2..1fa19c55d2 100644
--- a/public/img/github.png
+++ b/public/img/auth/github.png
diff --git a/public/img/auth/gitlab.png b/public/img/auth/gitlab.png
new file mode 100644
index 0000000000..ca30b45901
--- /dev/null
+++ b/public/img/auth/gitlab.png
diff --git a/public/img/auth/google_plus.png b/public/img/auth/google_plus.png
new file mode 100644
index 0000000000..720824230a
--- /dev/null
+++ b/public/img/auth/google_plus.png
diff --git a/public/img/auth/openid_connect.png b/public/img/auth/openid_connect.png
new file mode 100644
index 0000000000..af033cd1fe
--- /dev/null
+++ b/public/img/auth/openid_connect.png
diff --git a/public/img/auth/twitter.png b/public/img/auth/twitter.png
new file mode 100644
index 0000000000..a4f14de57a
--- /dev/null
+++ b/public/img/auth/twitter.png
diff --git a/public/js/index.js b/public/js/index.js
index 9b48c24cd3..31b15a76a7 100644
--- a/public/js/index.js
+++ b/public/js/index.js
@@ -1047,6 +1047,56 @@ function initAdmin() {
         }
     }
 
+    function onOAuth2Change() {
+        $('.open_id_connect_auto_discovery_url, .oauth2_use_custom_url').hide();
+        $('.open_id_connect_auto_discovery_url input[required]').removeAttr('required');
+
+        var provider = $('#oauth2_provider').val();
+        switch (provider) {
+            case 'github':
+            case 'gitlab':
+                $('.oauth2_use_custom_url').show();
+                break;
+            case 'openidConnect':
+                $('.open_id_connect_auto_discovery_url input').attr('required', 'required');
+                $('.open_id_connect_auto_discovery_url').show();
+                break;
+        }
+        onOAuth2UseCustomURLChange();
+    }
+
+    function onOAuth2UseCustomURLChange() {
+        var provider = $('#oauth2_provider').val();
+        $('.oauth2_use_custom_url_field').hide();
+        $('.oauth2_use_custom_url_field input[required]').removeAttr('required');
+
+        if ($('#oauth2_use_custom_url').is(':checked')) {
+            if (!$('#oauth2_token_url').val()) {
+                $('#oauth2_token_url').val($('#' + provider + '_token_url').val());
+            }
+            if (!$('#oauth2_auth_url').val()) {
+                $('#oauth2_auth_url').val($('#' + provider + '_auth_url').val());
+            }
+            if (!$('#oauth2_profile_url').val()) {
+                $('#oauth2_profile_url').val($('#' + provider + '_profile_url').val());
+            }
+            if (!$('#oauth2_email_url').val()) {
+                $('#oauth2_email_url').val($('#' + provider + '_email_url').val());
+            }
+            switch (provider) {
+                case 'github':
+                    $('.oauth2_token_url input, .oauth2_auth_url input, .oauth2_profile_url input, .oauth2_email_url input').attr('required', 'required');
+                    $('.oauth2_token_url, .oauth2_auth_url, .oauth2_profile_url, .oauth2_email_url').show();
+                    break;
+                case 'gitlab':
+                    $('.oauth2_token_url input, .oauth2_auth_url input, .oauth2_profile_url input').attr('required', 'required');
+                    $('.oauth2_token_url, .oauth2_auth_url, .oauth2_profile_url').show();
+                    $('#oauth2_email_url').val('');
+                    break;
+            }
+        }
+    }
+
     // New authentication
     if ($('.admin.new.authentication').length > 0) {
         $('#auth_type').change(function () {
@@ -1075,22 +1125,28 @@ function initAdmin() {
                     break;
                 case '6':     // OAuth2
                     $('.oauth2').show();
-                    $('.oauth2 input').attr('required', 'required');
+                    $('.oauth2 div.required:not(.oauth2_use_custom_url,.oauth2_use_custom_url_field,.open_id_connect_auto_discovery_url) input').attr('required', 'required');
+                    onOAuth2Change();
                     break;
             }
-
             if (authType == '2' || authType == '5') {
                 onSecurityProtocolChange()
             }
         });
         $('#auth_type').change();
-        $('#security_protocol').change(onSecurityProtocolChange)
+        $('#security_protocol').change(onSecurityProtocolChange);
+        $('#oauth2_provider').change(onOAuth2Change);
+        $('#oauth2_use_custom_url').change(onOAuth2UseCustomURLChange);
     }
     // Edit authentication
     if ($('.admin.edit.authentication').length > 0) {
         var authType = $('#auth_type').val();
         if (authType == '2' || authType == '5') {
             $('#security_protocol').change(onSecurityProtocolChange);
+        } else if (authType == '6') {
+            $('#oauth2_provider').change(onOAuth2Change);
+            $('#oauth2_use_custom_url').change(onOAuth2UseCustomURLChange);
+            onOAuth2Change();
         }
     }
 
diff --git a/public/less/_form.less b/public/less/_form.less
index fc0fdddad1..4542c092db 100644
--- a/public/less/_form.less
+++ b/public/less/_form.less
@@ -56,7 +56,7 @@
 			}
 		}
 		a {
-		  margin-right: 5px;
+		  margin-right: 3px;
 			&:last-child {
 			  margin-right: 0px;
 			}
@@ -64,6 +64,9 @@
 		img {
 		  width: 32px;
 		  height: 32px;
+		  &.openidConnect {
+			width: auto;
+		  }
 		}
 	}
 }