[online] Remove GENERATOR_HOST defaults (#3289)

The defaults configured for GENERATOR_HOST didn't really make sense.
When running the docker container with `-P`, GENERATOR_HOST defaulted to
http://localhost. This caused download links for generated client/server
code to be incorrect. For most cases, there's no reason to provide
GENERATOR_HOST as the code already figures the appropriate
scheme/host/port from the originating request.

GENERATOR_HOST could still be used for more complex deployment
scenarios, for instance if a specific server is configured as a file
server. I haven't tested this scenario, and it may require mounting /tmp
as a volume when running within a container.

.hub.online.dockerfile

@@ -28,7 +28,7 @@ WORKDIR ${TARGET_DIR}
 
 COPY --from=builder ${GEN_DIR}/modules/openapi-generator-online/target/openapi-generator-online.jar ${TARGET_DIR}/openapi-generator-online.jar
 
-ENV GENERATOR_HOST=http://localhost
+ENV GENERATOR_HOST=""
 
 EXPOSE 8080
 

README.md

@@ -281,7 +281,7 @@ Example usage:
 
 ```sh
 # Start container at port 8888 and save the container id
-> CID=$(docker run -d -p 8888:8080 -e GENERATOR_HOST=http://localhost:8888 openapitools/openapi-generator-online)
+> CID=$(docker run -d -p 8888:8080 openapitools/openapi-generator-online)
 
 # allow for startup
 > sleep 10

docs/online.md

@@ -23,9 +23,7 @@ Example usage:
 
 ```bash
 # Start container at port 8888 and save the container id
-CID=$(docker run -d -p 8888:8080 \
-        -e GENERATOR_HOST=http://localhost:8888 \
-        openapitools/openapi-generator-online)
+CID=$(docker run -d -p 8888:8080 openapitools/openapi-generator-online)
 
 # allow for startup
 sleep 10

modules/openapi-generator-online/Dockerfile

@@ -6,7 +6,9 @@ COPY target/openapi-generator-online.jar /generator/openapi-generator-online.jar
 
 # 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
+# Generally, this "just works" without GENERATOR_HOST, and this is provided only as
+# a workaround if all else fails.
+ENV GENERATOR_HOST=""
 
 EXPOSE 8080
 

modules/openapi-generator-online/README.md

@@ -46,9 +46,12 @@ 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
+docker run -d -p 8888:8080 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.
+
+## Environment
+
+`GENERATOR_HOST` can be set to force the scheme/host/port used for download link generation. In most cases, this environment variable is not
+necessary to be set and the download link will be generated to match the originating request. The variable is provided simply as a fallback.