[BUG] [rust-client] Unable to generate rust client for docker api

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• What's the version of OpenAPI Generator used?
• Have you search for related issues/PRs?
• What's the actual output vs expected output?
• [Optional] Bounty to sponsor the fix (example)

Description

openapi-generator successfully generates an output for the Docker engine v1.39 spec, albeit with a number of warnings such as

[main] WARN  o.o.codegen.DefaultCodegen - codegenModel is null. Default to UNKNOWN_BASE_TYPE

...

[main] WARN  o.o.c.examples.ExampleGenerator - example value (array/primitive) not handled at the moment: [{ID=ktnbjxoalbkvbvedmg1urrz8h, Version={Index=11}, CreatedAt=2016-11-05T01:20:17.327670065Z, UpdatedAt=2016-11-05T01:20:17.327670065Z, Spec={Name=server.conf}}]

Full output here.

Upon attempting to compile the resulting code, there are numerous errors from the Rust compiler such as:

error[E0412]: cannot find type `Value` in this scope
  --> src/apis/container_api.rs:52:76
   |
52 |     fn container_stats(&self, id: &str, stream: bool) -> Box<Future<Item = Value, Error = Error<serde_json::Value>>>;

...

error[E0277]: the trait bound `models::File: serde::Serialize` is not satisfied
  --> src/apis/plugin_api.rs:58:14
   |
58 |             .with_body_param(body)
   |              ^^^^^^^^^^^^^^^ the trait `serde::Serialize` is not implemented for `models::File`

error: aborting due to 25 previous errors

Full compiler output here.

openapi-generator version

(base) Patricks-MBP:test1 pgrinaway$ openapi-generator version
3.3.4

OpenAPI declaration file content or url

The OpenAPI declaration can be found here

Command line used for generation

I ran:

openapi-generator generate -i https://docs.docker.com/engine/api/v1.39/swagger.yaml -g rust -o rust_client/

Using openapi-generator version 3.3.4 on Mac OS X Mojave 10.14.3.
Cargo version cargo 1.32.0 (8610973aa 2019-01-02)

Steps to reproduce

Generate the rust code:

mkdir rust_docker && openapi-generator generate -i https://docs.docker.com/engine/api/v1.39/swagger.yaml -g rust -o rust_docker/

Attempt to compile:

cd rust_docker && cargo build

Related issues/PRs

I'm not sure if #2527 is related, since it is trying to also generate a client for this API. Possibly PR #2244 is related, but again I am unsure.

Suggest a fix

I am relatively new to rust, but manually inserting a use serde_json::Value; in the generated code did make the error about the Value go away. However, I'm not quite sure how to fix the other errors.

Reproduce the issue with the Docker v1.39 swagger.yaml using the stated openapi-generator command, then run cargo build in the generated rust_docker project. Inspect the reported errors in src/apis/container_api.rs and src/apis/plugin_api.rs and the full compiler output. Done means the generated Rust client compiles without the reported errors.