Server-Side Routing

Server-side routing is used to specify what actions to take for target request addresses, calling handler functions or specifying static files, etc. If one doesn't match, the next is tried. The default server-side routing is as follows (if not written, it defaults to this):

server.configure(|ctx| {
    ctx.use_handlers(false);
});

Here the use_handlers function represents searching for matching handler functions for the request path. If found, it redirects to the corresponding handler function.

In addition to the above handler functions, there are several other routes:

OpenAPI Documentation

Add the following code in the configure function:

server.configure(|ctx| {
    // ...
    ctx.use_openapi("/doc/");
    // ...
});

The path refers to the address for requesting documentation. For production environments,尽量 avoid using documentation interfaces or change to complex paths to avoid exposing interfaces.

Local Directory Routing

Add the following code in the configure function:

server.configure(|ctx| {
    // ...
    ctx.use_location_route("/", "/wwwroot");
    // ...
});

The first parameter is the request path, and the second parameter is the local directory address. If a file /wwwroot/a.json exists, it can be accessed via the request /a.json.

Embedded Resource Routing

Add the following code in the configure function:

server.configure(|ctx| {
    // ...
    ctx.use_embedded_route("/", embed_dir!("assets/wwwroot"));
    // ...
});

Embedded resources mean that the directory specified by the embed_dir macro is built into the executable program at compile time. Subsequently, during runtime, it doesn't require the local path to exist and can still provide corresponding file request responses.

Memory Leak Debugging Routing

The implementation mechanism of this feature is to take over the program's memory allocation actions, recording the memory allocation location each time it allocates. Then at the dump location, it traverses all unreleased memory and prints memory allocation information. Enable the jemalloc feature of the potato library:

cargo add potato --features jemalloc

Then add the following code in the configure function:

server.configure(|ctx| {
    // ...
    ctx.use_jemalloc("/profile.pdf");
    // ...
});

This method requires the function's runtime environment to be Linux, and the following libraries to be installed:

# ubuntu/debian
sudo apt install libjemalloc-dev graphviz ghostscript

After running the service, request /profile.pdf to see the detailed memory allocation records of the program stack. If memory leak issues exist, focus on examining the functions with larger reports for troubleshooting.

Custom Routing

Add the following code in the configure function:

server.configure(|ctx| {
    // ...
    ctx.use_custom(|req| async { Some(HttpResponse::text("hello")) });
    // ...
});

The use_custom function allows you to insert custom request processing logic. It takes an asynchronous closure that receives a request and returns an optional response. If it returns Some(response), the response is returned directly without executing subsequent middleware or handlers; if it returns None, subsequent middleware or handlers continue to execute.

WebDAV Routing

Enable the webdav feature of the potato library:

cargo add potato --features webdav

Then add the following code in the configure function:

server.configure(|ctx| {
    // ...
    ctx.use_webdav_localfs("/webdav", "/tmp");
    // ctx.use_webdav_memfs("/webdav");
    // ...
});

Reverse Proxy Routing

Add the following code in the configure function:

server.configure(|ctx| {
    // ...
    ctx.use_reverse_proxy("/", "http://www.fawdlstty.com", true);
    // ...
});

The use_reverse_proxy function is used to set up reverse proxy routing, and it accepts three parameters:

• First parameter url_path: local path prefix, specifying which request paths need to be proxied
• Second parameter proxy_url: target proxy server address, requests will be forwarded to this address
• Third parameter modify_content: boolean value, specifying whether to modify URLs in the response content (replace proxy server address with local path)

When modify_content is set to true, proxy server addresses in the response content will be replaced with the local path, which is very useful for handling hardcoded URLs in static resources. This feature supports WebSocket connection proxying and can automatically handle protocol upgrades.