[FIXED JENKINS-10675] use X-Forwarded-Proto if present

core/src/main/java/jenkins/model/Jenkins.java

@@ -1916,7 +1916,12 @@ public class Jenkins extends AbstractCIBase implements ModifiableTopLevelItemGro
     public String getRootUrlFromRequest() {
         StaplerRequest req = Stapler.getCurrentRequest();
         StringBuilder buf = new StringBuilder();
-        buf.append(req.getScheme()+"://");
+        String scheme = req.getScheme();
+        String forwardedScheme = req.getHeader("X-Forwarded-Proto");
+        if (forwardedScheme != null) {
+            scheme = forwardedScheme;
+        }
+        buf.append(scheme+"://");
         buf.append(req.getServerName());
         if(req.getServerPort()!=80)
             buf.append(':').append(req.getServerPort());

core/src/test/java/jenkins/model/JenkinsGetRootUrlTest.java

@@ -102,6 +102,30 @@ public class JenkinsGetRootUrlTest {
         accessing("http://localhost:8080/");
         rootUrlIs("https://ci/jenkins/");
     }
+    
+    @Bug(10675)
+    @Test
+    public void useForwardedProtoWhenPresent() {
+        configured("https://ci/jenkins/");
+        
+        // Without a forwarded protocol, it should use the request protocol
+        accessing("http://ci/jenkins/");
+        rootUrlFromRequestIs("http://ci/jenkins/");
+        
+        // With a forwarded protocol, it should use the forwarded protocol
+        accessing("http://ci/jenkins/");
+        withHeader("X-Forwarded-Proto", "https");
+        rootUrlFromRequestIs("https://ci/jenkins/");
+        
+        accessing("https://ci/jenkins/");
+        withHeader("X-Forwarded-Proto", "http");
+        rootUrlFromRequestIs("http://ci/jenkins/");
+    }
+    
+    private void rootUrlFromRequestIs(final String expectedRootUrl) {
+        
+        assertThat(jenkins.getRootUrlFromRequest(), equalTo(expectedRootUrl));
+    }
 
     private void rootUrlIs(final String expectedRootUrl) {
 
@@ -112,6 +136,11 @@ public class JenkinsGetRootUrlTest {
 
         when(config.getUrl()).thenReturn(configuredHost);
     }
+    
+    private void withHeader(String name, String value) {
+        final StaplerRequest req = Stapler.getCurrentRequest();
+        when(req.getHeader(name)).thenReturn(value);
+    }
 
     private void accessing(final String realUrl) {