Compatibility with tower and http

[XAMPPRocky]

Hello, the growing popularity of "Sans I/O" HTTP clients has brought some tension between reqwest and other HTTP client libraries including hyper, as currently reqwest does not implement tower::Service at all, and even if it did, reqwest currently uses its own Response type instead of http::Response, meaning that libraries like kube-rs cannot be used with reqwest at all.

It would be nice if reqwest could integrate with rest of the ecosystem, or at the very least provide a compatibility layer for people who want to use reqwest as the client for their tower services.

[jennydaman]

Client implements Service

#491 (comment)

[XAMPPRocky]

@jennydaman Thanks for the update, but as I mention in the original post, reqwest still uses its own HTTP Request and Response types for the Service, so that means you can't use it with HTTP libraries like kube-rs because kube-rs's client looks like this.

Box<dyn tower::Service<http::Request, Response = http:Response>>

Where as currently reqwest is only implemented for tower::Service<reqwest::Request, Response = reqwest::Response> which means that functionally it's only generic over its own types, and still can't be used interchangeably in the wider ecosystem.

[shouya]

I was thinking about the same so I implemented #2060. You may give it a test.