Keep cookies between requests

You turn on a client's cookie store so a cookie one response sets is sent on the requests after it, the way a browser keeps you logged in.

fibre_http = "0"

Set up the project#

Start a new binary crate.

cargo new cookies
cd cookies

Put this in the [dependencies] section of Cargo.toml:

[dependencies]
fibre_http = { version = "0", features = ["cookies", "json"] }
serde_json = "1"

The cookies feature adds the cookie store. The json feature is only there to read httpbin's answer.

The program#

httpbin.org's /cookies/set answers with a Set-Cookie header. Its /cookies endpoint shows which cookies your request carried. Replace src/main.rs with this:

use fibre_http::SyncClient;
use serde_json::Value;

fn main() -> Result<(), fibre_http::Error> {
    let plain = SyncClient::new();
    plain.get("https://httpbin.org/cookies/set?session=abc123").send()?;
    let seen: Value = plain.get("https://httpbin.org/cookies").send()?.json()?;
    println!("without a cookie store: {}", seen["cookies"]);

    let client = SyncClient::builder().cookie_store(true).build_sync()?;
    client.get("https://httpbin.org/cookies/set?session=abc123").send()?;
    let seen: Value = client.get("https://httpbin.org/cookies").send()?.json()?;
    println!("with a cookie store: {}", seen["cookies"]);
    Ok(())
}

Run it:

$ cargo run
without a cookie store: {}
with a cookie store: {"session":"abc123"}

What each part does#

A plain client ignores Set-Cookie, so the second request goes out with no cookies.

cookie_store(true) gives the client an in-memory store. It saves every cookie a response sets, including responses to redirects it follows on the way. Later requests carry the cookies that match their domain and path.

The store lives as long as the client and the clients cloned from it. If you set a Cookie header on a request yourself, that request keeps yours.

Where to go next#

The usage guide shows a login form posted with form and a page fetched after it: https://github.com/excsn/fibre/blob/main/http/README.USAGE.md