octorust: Getting the request URL and request headers that were used

[ctsrc]

When I call a GitHub API endpoint using octorust, I want to be able to extract the URL and request headers that octorust used for the request.

In reqwest, you can use http::Extensions (https://docs.rs/http/latest/http/struct.Extensions.html) to attach additional data to requests and responses in middleware.

I use this in order to extract the GitHub API URL and request headers that octorust uses in its requests.

In order to access the inserted "extensions", I made a small patch for octorust that adds an extensions field to octorust::Response. In the patch, I populate this field by copying the data from reqwest::Response::extensions(). In this way, you can then use http::Extensions in middleware in code that makes use of octorust.

I am making this issue to describe the motivation for my patch, and I will be opening a PR with the patch.

[ctsrc]

PR opened: #98

[ctsrc]

For context, here is how I use the patched octorust in my program:

I have a middleware like this:

struct ReqSaverMiddleware;

#[async_trait::async_trait]
impl Middleware for ReqSaverMiddleware {
    async fn handle(
        &self,
        req: Request,
        extensions: &mut Extensions,
        next: Next<'_>,
    ) -> Result<Response> {
        let req_url = req.url().to_owned();
        let req_headers = req.headers().to_owned();
        let mut resp = next.run(req, extensions).await?;
        resp.extensions_mut().insert(req_url);
        resp.extensions_mut().insert(req_headers);
        Ok(resp)
    }
}

Construct a "custom client":

    let gh_client = {
        let reqwest_client = Client::builder().build()?;
        let gh_custom_client = ClientBuilder::new(reqwest_client)
            .with(ReqSaverMiddleware)
            .build();
        let http_cache = <dyn HttpCache>::noop();
        octorust::Client::custom("", None, gh_custom_client, http_cache)
    };

Send a GitHub API request like normal, for example:

let rate_limit_resp = gh_client.rate_limit().get().await?;

And then I can extract the GitHub URL and the request headers that octorust used:

let req_url: String = rate_limit_resp
    .extensions
    .get::<reqwest::Url>()
    .map(|u| u.as_str().to_owned())
    .expect("Middleware error: request URL lost");
let req_headers: crate::HeaderMap = rate_limit_resp
    .extensions
    .get::<reqwest::header::HeaderMap>()
    .map(Into::into)
    .expect("Middleware error: request headers lost");

And of course still getting the status, response headers and response body as before:

let resp_status = rate_limit_resp.status.as_u16();
let resp_headers: crate::HeaderMap = rate_limit_resp.headers.into();
let resp_body: Option<_> = Some(rate_limit_resp.body);

[ctsrc]

Being able to access the "extensions" that the reqwest::Response had from the octorust::Response has heaps of other use-cases as well too. This just happens to be the specific use-case that motivated me to create the patch and submit the draft PR.

[tamird]

These clients are generated; I don't think they are going to accept your manual edits of the github client.

[ctsrc]

@tamird I wasn't sure if the github/src/lib.rs file, which my PR is for, is also generated or if it's manually maintained.

But if that one is also generated I would highly appreciate some pointers from the repo owners on how that file is generated and I can edit my PR to apply the changes via the tools and/or templates they use for generating that file.