Panics now output to logs

NEXT_CHANGELOG.md

@@ -38,7 +38,6 @@ In addition, the following command line flags have changed:
 * `--apollo-schema-config-delivery-endpoint` -> `--apollo-uplink-url`
 * `--apollo-schema-poll-interval` -> `--apollo-uplink-poll-interval`
 
-### Rhai scripts should be able to do more things (like rust plugins) [PR #971](https://github.com/apollographql/router/pull/971)
 ### Add configuration to declare your own GraphQL endpoint [PR #976](https://github.com/apollographql/router/pull/976)
 You are now able to declare your own GraphQL endpoint in the config like this:
 ```yaml
@@ -56,6 +55,10 @@ This is a re-working of our rhai scripting support. The intent is to make writin
 
 ## 🚀 Features ( :rocket: )
 
+### Panics now output to logs  [PR #1001](https://github.com/apollographql/router/pull/1001)
+Previously panics would get swallowed. Now they are output to the logs.
+Setting `RUST_BACKTRACE=1` or `RUST_BACKTRACE=full` enables the full backtrace to also be logged.
+
 ### Apollo studio Usage Reporting [PR #898](https://github.com/apollographql/router/pull/898)
 If you have [enabled telemetry](https://www.apollographql.com/docs/router/configuration/apollo-telemetry#enabling-usage-reporting), you can now see field usage reporting for your queries by heading to the Apollo studio fields section.
 Here is more information on how to [set up telemetry](https://www.apollographql.com/docs/studio/metrics/usage-reporting#pushing-metrics-from-apollo-server) and [Field Usage](https://www.apollographql.com/docs/studio/metrics/field-usage)
@@ -109,4 +112,4 @@ Rather than pointing to our `LICENSE` file, we now use the `Elastic-2.0` SPDX li
 ## 📚 Documentation ( :books: )
 
 ### Add license notice to first line of Router output  [PR #986](https://github.com/apollographql/router/pull/986)
-Display the [ELv2 license](https://www.elastic.co/blog/elastic-license-v2) at the start of the Router
+Display the [ELv2 license](https://www.elastic.co/blog/elastic-license-v2) at the start of the Router

apollo-router/Cargo.toml

@@ -16,6 +16,7 @@ apollo-router-core = { path = "../apollo-router-core" }
 apollo-uplink = { path = "../uplink" }
 async-trait = "0.1.53"
 atty = "0.2.14"
+backtrace = "0.3.65"
 buildstructor = "0.1.12"
 bytes = "1.1.0"
 clap = { version = "3.1.3", default-features = false, features = ["env", "derive", "std"] }

apollo-router/src/executable.rs

@@ -200,6 +200,8 @@ pub async fn rt_main() -> Result<()> {
     let schema = match (opt.supergraph_path, opt.apollo_key) {
         (Some(supergraph_path), _) => {
             tracing::info!("{apollo_router_msg}");
+            setup_panic_handler();
+
             let supergraph_path = if supergraph_path.is_relative() {
                 current_directory.join(supergraph_path)
             } else {
@@ -276,6 +278,23 @@ pub async fn rt_main() -> Result<()> {
     Ok(())
 }
 
+fn setup_panic_handler() {
+    // Redirect panics to the logs.
+    let backtrace_env = std::env!("RUST_BACKTRACE");
+    let show_backtraces = backtrace_env == "1" || backtrace_env == "full";
+    if show_backtraces {
+        tracing::warn!("RUST_BACKTRACE={} detected. This use useful for diagnostics but will have a performance impact and may leak sensitive information", backtrace_env);
+    }
+    std::panic::set_hook(Box::new(move |e| {
+        if show_backtraces {
+            let backtrace = backtrace::Backtrace::new();
+            tracing::error!("{}\n{:?}", e, backtrace)
+        } else {
+            tracing::error!("{}", e)
+        }
+    }));
+}
+
 fn copy_args_to_env() {
     // Copy all the args to env.
     // This way, Clap is still responsible for the definitive view of what the current options are.

apollo-router/tests/integration_tests.rs

@@ -541,6 +541,10 @@ async fn setup_router_and_registry() -> (
     BoxCloneService<RouterRequest, RouterResponse, BoxError>,
     CountingServiceRegistry,
 ) {
+    std::panic::set_hook(Box::new(|e| {
+        let backtrace = backtrace::Backtrace::new();
+        tracing::error!("{}\n{:?}", e, backtrace)
+    }));
     let schema: Arc<Schema> =
         Arc::new(include_str!("fixtures/supergraph.graphql").parse().unwrap());
     let counting_registry = CountingServiceRegistry::new();