Date header

[jayvdb]

According to RFC 9110:

An origin server with a clock (as defined in Section 5.6.7) MUST generate a Date header field in all 2xx (Successful), 3xx (Redirection), and 4xx (Client Error) responses, and MAY generate a Date header field in 1xx (Informational) and 5xx (Server Error) responses.

An origin server without a clock MUST NOT generate a Date header field.

and Section 5.6.7 is

A "clock" is an implementation capable of providing a reasonable approximation of the current instant in UTC. A clock implementation ought to use NTP ([RFC5905]), or some similar protocol, to synchronize with UTC.

actix-web cant be 100% sure that the time it sees (e.g. use of std::time is using NTP or similar, but it is highly likely, especially given that actix cant build without std

Given this is a MUST, IMO it would be great for actix-web to provide an easy way to comply with the spec.

Using map_response the implementation is roughly

/// Middleware to add Date header to all responses.
/// Usage: `App::new().wrap(map_response(add_date_header))`
async fn add_date_header(
    mut res: actix_web::dev::ServiceResponse<impl actix_web::body::MessageBody>,
) -> actix_web::Result<actix_web::dev::ServiceResponse<impl actix_web::body::MessageBody>> {
    res.headers_mut().insert(
        actix_web::http::header::DATE,
        actix_web::http::header::HttpDate::from(std::time::SystemTime::now()).try_into_value()?,
    );

    Ok(res)
}

[robjtede]

Great news, Actix Web already does this automatically!

 › curl -v http://127.0.0.1:8080
*   Trying 127.0.0.1:8080...
* Connected to 127.0.0.1 (127.0.0.1) port 8080
> GET / HTTP/1.1
> Host: 127.0.0.1:8080
> User-Agent: curl/8.4.0
> Accept: */*
>
< HTTP/1.1 200 OK
< content-length: 6
< date: Wed, 24 Jan 2024 03:52:04 GMT         <-------------------
<
* Connection #0 to host 127.0.0.1 left intact
Hello!%

 › curl -v --http2-prior-knowledge http://127.0.0.1:8080
*   Trying 127.0.0.1:8080...
* Connected to 127.0.0.1 (127.0.0.1) port 8080
* [HTTP/2] [1] OPENED stream for http://127.0.0.1:8080/
* [HTTP/2] [1] [:method: GET]
* [HTTP/2] [1] [:scheme: http]
* [HTTP/2] [1] [:authority: 127.0.0.1:8080]
* [HTTP/2] [1] [:path: /]
* [HTTP/2] [1] [user-agent: curl/8.4.0]
* [HTTP/2] [1] [accept: */*]
> GET / HTTP/2
> Host: 127.0.0.1:8080
> User-Agent: curl/8.4.0
> Accept: */*
>
< HTTP/2 200
< content-length: 6
< date: Wed, 24 Jan 2024 03:52:10 GMT          <-------------------
<
* Connection #0 to host 127.0.0.1 left intact
Hello!%

[jayvdb]

Thanks for the clue bat. Apologies for it being a silly question.

I was testing using actix_web::test::init_service and found that it wasnt adding a Date header. I've moved on to using actix_test::start which does provide the Date header.

Perhaps https://actix.rs/docs/testing/ should indicate that the actix_web::test interface doesnt include some headers.

[robjtede]

Yea there's lots of improvements to be made to the testing docs. I'll remember to include this note as an example of server test != service test.