[online] Revert GENERATOR_HOST explicit setting (#3287)

modules/openapi-generator-online/Dockerfile

@@ -4,9 +4,10 @@ WORKDIR /generator
 
 COPY target/openapi-generator-online.jar /generator/openapi-generator-online.jar
 
-ENV GENERATOR_HOST=http://localhost
+# GENERATOR_HOST can be used to determine the target location of a download link.
+# The default value asumes binding to host via: docker -p 8080:8080 image_name
+ENV GENERATOR_HOST=http://localhost:8080
 
 EXPOSE 8080
 
-CMD ["java", "-jar", "/generator/openapi-generator-online.jar"]
-
+CMD ["java", "-jar", "/generator/openapi-generator-online.jar" ]

modules/openapi-generator-online/README.md

@@ -1,15 +1,54 @@
 # OpenAPI generated server
 
-Spring Boot Server 
+A Spring Boot Server application which hosts a client/server generator API.
 
 
 ## Overview  
+
 This server was generated by the [OpenAPI Generator](https://openapi-generator.tech) project.
-By using the [OpenAPI-Spec](https://openapis.org), you can easily generate a server stub.
+By using the [OpenAPI-Spec](https://openapis.org), you can easily generate a server stub or one of 100+ client packages.
+
 This is an example of building a OpenAPI-enabled server in Java using the SpringBoot framework.
 
 The underlying library integrating OpenAPI to SpringBoot is [springfox](https://github.com/springfox/springfox)
 
-Start your server as a simple java application
+## Building
 
-Change default port value in application.properties
+Refer to [root README](../../README.md) for build directions.
+
+## Running
+
+### Via command line
+
+Running is as simple as:
+
+```
+java -jar ./target/openapi-generator-online.jar
+```
+
+This exposes the API on local port 8080.
+
+Springfox supports configuration of the "host" value in the output OpenAPI document by setting the `Host` HTTP header in the request.
+To set this explicitly, pass the system property `springfox.documentation.swagger.v2.host` with the desired host. For example:
+
+```
+java -Dspringfox.documentation.swagger.v2.host=example.com:8888 -jar ./target/openapi-generator-online.jar
+```
+
+### Via Docker
+
+After building from source, change to this module directory (`cd modules/openapi-generator-online`) and build the docker image:
+
+```
+docker build -t openapitools/openapi-generator-online:latest .
+```
+
+Now, run the docker image:
+
+```
+docker run -d -p 8888:8080 \
+        -e GENERATOR_HOST=http://localhost:8888 \
+        openapitools/openapi-generator-online
+```
+
+The `GENERATOR_HOST` variable is used here to ensure download links generated by the API refer to the proper API location.

modules/openapi-generator-online/src/main/java/org/openapitools/codegen/online/configuration/OpenAPIDocumentationConfig.java

@@ -52,7 +52,6 @@ public class OpenAPIDocumentationConfig {
 
         String version = properties.getProperty("version", "unknown");
 
-
         return new ApiInfoBuilder()
             .title("OpenAPI Generator Online")
             .description("This is an online openapi generator server.  You can find out more at https://github.com/OpenAPITools/openapi-generator.")
@@ -66,18 +65,7 @@ public class OpenAPIDocumentationConfig {
 
     @Bean
     public Docket customImplementation(){
-        String host;
-        try {
-            String baseUrl = System.getenv("GENERATOR_HOST");
-            if (baseUrl == null) {
-                baseUrl = System.getProperty("generator.host", "http://localhost");
-            }
-            host = new URI(baseUrl).getHost();
-        } catch (URISyntaxException e) {
-            host = "";
-        }
         return new Docket(DocumentationType.SWAGGER_2)
-                .host(host)
                 .select()
                     .apis(RequestHandlerSelectors.basePackage("org.openapitools.codegen.online.api"))
                     .build()