prololo: provide more context in errors

src/bot/mod.rs

@@ -4,6 +4,7 @@ use std::{
     path::PathBuf,
 };
 
+use anyhow::Context;
 use matrix_sdk::{
     room::Room,
     ruma::events::{room::member::MemberEventContent, StrippedStateEvent},
@@ -37,7 +38,9 @@ impl Prololo {
     ///
     /// The bot is ready to run once this function has been called.
     pub async fn init(&self) -> anyhow::Result<()> {
-        self.load_or_init_session().await?;
+        self.load_or_init_session()
+            .await
+            .context("couldn't init session for matrix bot")?;
 
         let authorized_rooms = vec![self.config.matrix_room_id.clone()];
 

src/main.rs

@@ -2,6 +2,7 @@ use std::fs::File;
 use std::io::BufReader;
 use std::path::PathBuf;
 
+use anyhow::Context;
 use clap::Clap;
 use rocket::routes;
 
@@ -27,11 +28,13 @@ async fn main() -> anyhow::Result<()> {
     tracing_subscriber::fmt::init();
 
     let opts = Opts::parse();
-    let config_file = opts.config;
-    let config: ProloloConfig = serde_yaml::from_reader(BufReader::new(File::open(config_file)?))?;
+    let config_file = File::open(&opts.config)
+        .with_context(|| format!("couldn't open {}:", opts.config.display()))?;
+    let config: ProloloConfig = serde_yaml::from_reader(BufReader::new(config_file))
+        .context("couldn't parse config file")?;
 
-    let prololo = Prololo::new(config)?;
-    prololo.init().await?;
+    let prololo = Prololo::new(config).context("failed to create prololo bot")?;
+    prololo.init().await.context("failed to init prololo bot")?;
     tokio::spawn(async move { prololo.run().await });
 
     let rocket = rocket::build().mount("/", routes![github_webhook]);

src/webhooks/github.rs

@@ -8,7 +8,7 @@ use serde::Deserialize;
 
 mod signing;
 use signing::SignedGitHubPayload;
-use tracing::info;
+use tracing::{debug, info, warn};
 
 const X_GITHUB_EVENT: &str = "X-GitHub-Event";
 
@@ -31,6 +31,7 @@ pub enum GitHubEventType {
     Issues,
     IssueComment,
     Push,
+    Unknown,
 }
 
 #[rocket::async_trait]
@@ -48,10 +49,24 @@ impl<'r> FromRequest<'r> for GitHubEventType {
 
         let event_type = event_types[0];
 
-        match serde_json::from_str::<GitHubEventType>(event_type) {
-            Ok(ev_type) => Outcome::Success(ev_type),
-            Err(e) => Outcome::Failure((Status::BadRequest, anyhow!(e))),
+        // HACK: serialize the Rust String to a JSON string so that it's deserializable into the
+        // GitHubEventType enum correctly:
+        //
+        // - `create` is not a valid JSON string
+        // - `"create"` is!
+        let event_type_json_value =
+            serde_json::to_value(event_type).expect("`String` serialization should never fail");
+        let event_type = match serde_json::from_value::<GitHubEventType>(event_type_json_value) {
+            Ok(ev_type) => ev_type,
+            Err(e) => {
+                warn!("received unknown event type: {}, {}", event_type, e);
+                GitHubEventType::Unknown
             }
+        };
+
+        debug!("received request with type {:?}", event_type);
+
+        Outcome::Success(event_type)
     }
 }
 

src/webhooks/github/signing.rs

@@ -7,12 +7,14 @@ use rocket::{
     http::{ContentType, Status},
     Data, Request, State,
 };
+use tracing::trace;
 
 use crate::webhooks::github::GitHubSecret;
 
 const X_GITHUB_SIGNATURE: &str = "X-Hub-Signature-256";
 
 fn validate_signature(secret: &str, signature: &str, data: &str) -> bool {
+    trace!("validating signature...");
     use hmac::{Hmac, Mac, NewMac};
     use sha2::Sha256;
 
@@ -54,6 +56,7 @@ impl<'r> FromData<'r> for SignedGitHubPayload {
     type Error = anyhow::Error;
 
     async fn from_data(request: &'r Request<'_>, data: Data<'r>) -> Outcome<'r, Self> {
+        trace!("received payload on GitHub webhook endpoint");
         let json_ct = ContentType::new("application", "json");
         if request.content_type() != Some(&json_ct) {
             return Outcome::Failure((Status::BadRequest, anyhow!("wrong content type")));
@@ -90,6 +93,7 @@ impl<'r> FromData<'r> for SignedGitHubPayload {
             return Outcome::Failure((Status::BadRequest, anyhow!("couldn't verify signature")));
         }
 
+        trace!("validated GitHub payload");
         Outcome::Success(SignedGitHubPayload(content))
     }
 }