Inconsistent use of GENERATOR_HOST value

Description

While using swaggerapi/swagger-generator:2.4.13 docker image in a multi-container pod along with swagger-editor, noticed server code generation response does not use the value of GENERATOR_HOST env variable. Whereas client code generation honors the value of GENERATOR_HOST

Swagger-codegen version

• swagger-generator:2.4.13
• I think it might be the case for swaggerapi/swagger-generator-v3:3.0.19 too

Swagger declaration file content or url

Use petstore swagger file, which is embedded in the the editor.

Command line used for generation

Not Applicable

Steps to reproduce

Use Developer Tools in Chrome to track Network requests, and preview response.

• Create docker container
  docker run -d -e GENERATOR_HOST=http://locahost:81 -p 80:8080 swaggerapi/swagger-generator:2.4.13
• Open browser and point to http://localhost/. Swagger Editor UI with Pet Store
• Open Developer tools and click on Network tab
• Generate Client code for any language.
• Notice download of Client zip file fails, as the editor is trying to download from http://localhost:81 (EXPECTED. It honors GENERATOR_HOST env variable)
• Generate Server code for any language.
• Server code downloads.
  (UNEXPECTED. It does not honor GENERATOR_HOST env variable)

Related issues/PRs

Unable to find any related

Suggest a fix/enhancement

Able to fix using the below patch

diff --git modules/swagger-generator/src/main/java/io/swagger/generator/resource/SwaggerResource.java modules/swagger-generator/src/main/java/io/swagger/generator/resource/SwaggerResource.java
index 4220e1034..207394f73 100644
--- modules/swagger-generator/src/main/java/io/swagger/generator/resource/SwaggerResource.java
+++ modules/swagger-generator/src/main/java/io/swagger/generator/resource/SwaggerResource.java
@@ -91,19 +91,7 @@ public class SwaggerResource {
             throws Exception {
 
         String filename = Generator.generateClient(language, opts);
-        String host = System.getenv("GENERATOR_HOST");
-
-        if (StringUtils.isBlank(host)) {
-            String scheme = request.getHeader("X-SSL");
-            String port = "";
-            if ("1".equals(scheme)) {
-                scheme = "https";
-            } else {
-                scheme = request.getScheme();
-                port = ":" + request.getServerPort();
-            }
-            host = scheme + "://" + request.getServerName() + port;
-        }
+        String host = getHost(request);
 
         if (filename != null) {
             String code = String.valueOf(UUID.randomUUID().toString());
@@ -192,9 +180,7 @@ public class SwaggerResource {
         String filename = Generator.generateServer(framework, opts);
         System.out.println("generated name: " + filename);
 
-        String host =
-                request.getScheme() + "://" + request.getServerName() + ":"
-                        + request.getServerPort();
+        String host = getHost(request);
 
         if (filename != null) {
             String code = String.valueOf(UUID.randomUUID().toString());
@@ -209,4 +195,11 @@ public class SwaggerResource {
             return Response.status(500).build();
         }
     }
+
+    private String getHost( HttpServletRequest request){
+        String host = System.getenv("GENERATOR_HOST");
+        return StringUtils.isBlank(host)
+               ? (request.getScheme() + "://" + request.getServerName() + ":" + request.getServerPort())
+               : host;
+    }
 }

Inspect modules/swagger-generator/src/main/java/io/swagger/generator/resource/SwaggerResource.java, focusing on how the client and server generation responses construct their download hosts. Reproduce the behavior with the swagger-generator:2.4.13 Docker image, GENERATOR_HOST, and the embedded Petstore definition; done means server downloads honor the configured host as client downloads do.