Log curl command line for all requests at trace

src/api/server_server.rs

@@ -64,7 +64,7 @@ use ruma::{
 };
 use serde_json::value::{to_raw_value, RawValue as RawJsonValue};
 use tokio::sync::RwLock;
-use tracing::{debug, error, field, warn};
+use tracing::{debug, error, field, trace, trace_span, warn};
 
 use super::appservice_server;
 use crate::{
@@ -253,6 +253,14 @@ where
         signature,
     )));
 
+    // can be enabled selectively using `filter =
+    // grapevine[outgoing_request_curl]=trace` in config
+    trace_span!("outgoing_request_curl").in_scope(|| {
+        trace!(
+            cmd = utils::curlify(&http_request),
+            "curl command line for outgoing request"
+        );
+    });
     let reqwest_request = reqwest::Request::try_from(http_request)?;
 
     let url = reqwest_request.url().clone();

src/main.rs

@@ -147,26 +147,42 @@ async fn run_server() -> Result<(), error::Serve> {
     let middlewares = ServiceBuilder::new()
         .sensitive_headers([header::AUTHORIZATION])
         .layer(axum::middleware::from_fn(spawn_task))
-        .layer(TraceLayer::new_for_http().make_span_with(
-            |request: &http::Request<_>| {
-                let endpoint = if let Some(endpoint) =
-                    request.extensions().get::<MatchedPath>()
-                {
-                    endpoint.as_str()
-                } else {
-                    request.uri().path()
-                };
+        .layer(
+            TraceLayer::new_for_http()
+                .make_span_with(|request: &http::Request<_>| {
+                    let endpoint = if let Some(endpoint) =
+                        request.extensions().get::<MatchedPath>()
+                    {
+                        endpoint.as_str()
+                    } else {
+                        request.uri().path()
+                    };
 
-                let method = request.method();
+                    let method = request.method();
 
-                tracing::info_span!(
-                    "http_request",
-                    otel.name = format!("{method} {endpoint}"),
-                    %method,
-                    %endpoint,
-                )
-            },
-        ))
+                    tracing::info_span!(
+                        "http_request",
+                        otel.name = format!("{method} {endpoint}"),
+                        %method,
+                        %endpoint,
+                    )
+                })
+                .on_request(
+                    |request: &http::Request<_>, _span: &tracing::Span| {
+                        // can be enabled selectively using `filter =
+                        // grapevine[incoming_request_curl]=trace` in config
+                        tracing::trace_span!("incoming_request_curl").in_scope(
+                            || {
+                                tracing::trace!(
+                                    cmd = utils::curlify(request),
+                                    "curl command line for incoming request \
+                                     (guessed hostname)"
+                                );
+                            },
+                        );
+                    },
+                ),
+        )
         .layer(axum::middleware::from_fn(unrecognized_method))
         .layer(
             CorsLayer::new()

src/utils.rs

@@ -306,6 +306,66 @@ impl<'a> TryFrom<&'a MxcUri> for MxcData<'a> {
     }
 }
 
+fn curlify_args<T>(req: &http::Request<T>) -> Option<Vec<String>> {
+    let mut args =
+        vec!["curl".to_owned(), "-X".to_owned(), req.method().to_string()];
+
+    for (name, val) in req.headers() {
+        args.extend([
+            "-H".to_owned(),
+            format!("{name}: {}", val.to_str().ok()?),
+        ]);
+    }
+
+    let fix_uri = || {
+        if req.uri().scheme().is_some() {
+            return None;
+        }
+        if req.uri().authority().is_some() {
+            return None;
+        }
+        let mut parts = req.uri().clone().into_parts();
+
+        parts.scheme = Some(http::uri::Scheme::HTTPS);
+
+        let host =
+            req.headers().get(http::header::HOST)?.to_str().ok()?.to_owned();
+        parts.authority =
+            Some(http::uri::Authority::from_maybe_shared(host).ok()?);
+
+        http::uri::Uri::from_parts(parts).ok()
+    };
+
+    let uri = if let Some(new_uri) = fix_uri() {
+        Cow::Owned(new_uri)
+    } else {
+        Cow::Borrowed(req.uri())
+    };
+
+    args.push(uri.to_string());
+
+    Some(args)
+}
+
+pub(crate) fn curlify<T>(req: &http::Request<T>) -> Option<String> {
+    let args = curlify_args(req)?;
+
+    Some(
+        args.into_iter()
+            .map(|arg| {
+                if arg.chars().all(|c| {
+                    c.is_alphanumeric() || ['-', '_', ':', '/'].contains(&c)
+                }) {
+                    arg
+                } else {
+                    format!("'{}'", arg.replace('\'', "\\'"))
+                }
+            })
+            .collect::<Vec<_>>()
+            .join(" "),
+    )
+}
+
 #[cfg(test)]
 mod tests {
     use crate::utils::dbg_truncate_str;