feat: wire MysqlError's ReportableError impl into TokenserverError (#1611)

* feat: wire MysqlError's ReportableError impl into TokenserverError

and quiet Pool errors

Closes SYNC-4424

* kluge: allow(clippy::result_large_err) for TokenserverError

(for now) we can get rid of this in a later refactoring

syncserver-db-common/src/error.rs

@@ -41,7 +41,11 @@ impl From<MysqlErrorKind> for MysqlError {
 
 impl ReportableError for MysqlError {
     fn is_sentry_event(&self) -> bool {
-        true
+        #[allow(clippy::match_like_matches_macro)]
+        match &self.kind {
+            MysqlErrorKind::Pool(_) => false,
+            _ => true,
+        }
     }
 
     fn metric_label(&self) -> Option<String> {

syncserver/src/tokenserver/extractors.rs

@@ -320,6 +320,7 @@ impl FromRequest for DbWrapper {
                 .map(Self)
                 .map_err(|e| TokenserverError {
                     context: format!("Couldn't acquire a database connection: {}", e),
+                    source: Some(Box::new(e)),
                     ..TokenserverError::internal_error()
                 })
         })

syncserver/src/tokenserver/mod.rs

@@ -1,4 +1,6 @@
+#[allow(clippy::result_large_err)]
 pub mod extractors;
+#[allow(clippy::result_large_err)]
 pub mod handlers;
 pub mod logging;
 

tokenserver-auth/src/lib.rs

@@ -3,7 +3,9 @@ mod crypto;
 
 #[cfg(not(feature = "py"))]
 pub use crypto::{JWTVerifier, JWTVerifierImpl};
+#[allow(clippy::result_large_err)]
 pub mod oauth;
+#[allow(clippy::result_large_err)]
 mod token;
 use syncserver_common::Metrics;
 pub use token::Tokenlib;

tokenserver-common/src/error.rs

@@ -11,7 +11,7 @@ use syncserver_common::{InternalError, ReportableError};
 
 /// An error type that represents application-specific errors to Tokenserver. This error is not
 /// used to represent database-related errors; database-related errors have their own type.
-#[derive(Clone, Debug)]
+#[derive(Debug)]
 pub struct TokenserverError {
     pub status: &'static str,
     pub location: ErrorLocation,
@@ -24,6 +24,10 @@ pub struct TokenserverError {
     pub backtrace: Box<Backtrace>,
     pub token_type: TokenType,
     pub tags: Option<Box<Vec<(&'static str, String)>>>,
+    /// TODO: refactor TokenserverError to include a TokenserverErrorKind, w/
+    /// variants for sources (currently just DbError). May require moving
+    /// TokenserverError out of common (into syncserver)
+    pub source: Option<Box<dyn ReportableError + Send>>,
 }
 
 #[derive(Clone, Debug)]
@@ -64,6 +68,7 @@ impl Default for TokenserverError {
             backtrace: Box::new(Backtrace::new()),
             token_type: TokenType::Oauth,
             tags: None,
+            source: None,
         }
     }
 }
@@ -275,14 +280,23 @@ impl From<TokenserverError> for HttpResponse {
 
 impl ReportableError for TokenserverError {
     fn backtrace(&self) -> Option<&Backtrace> {
+        if let Some(source) = &self.source {
+            return source.backtrace();
+        }
         Some(&self.backtrace)
     }
 
     fn is_sentry_event(&self) -> bool {
+        if let Some(source) = &self.source {
+            return source.is_sentry_event();
+        }
         self.http_status.is_server_error() && self.metric_label().is_none()
     }
 
     fn metric_label(&self) -> Option<String> {
+        if let Some(source) = &self.source {
+            return source.metric_label();
+        }
         if self.http_status.is_client_error() {
             match self.token_type {
                 TokenType::Oauth => Some("request.error.oauth".to_owned()),

tokenserver-db/src/error.rs

@@ -2,7 +2,7 @@ use std::fmt;
 
 use backtrace::Backtrace;
 use http::StatusCode;
-use syncserver_common::{from_error, impl_fmt_display, InternalError};
+use syncserver_common::{from_error, impl_fmt_display, InternalError, ReportableError};
 use syncserver_db_common::error::MysqlError;
 use thiserror::Error;
 use tokenserver_common::TokenserverError;
@@ -25,6 +25,29 @@ impl DbError {
     }
 }
 
+impl ReportableError for DbError {
+    fn backtrace(&self) -> Option<&Backtrace> {
+        match &self.kind {
+            DbErrorKind::Mysql(e) => e.backtrace(),
+            _ => Some(&self.backtrace),
+        }
+    }
+
+    fn is_sentry_event(&self) -> bool {
+        match &self.kind {
+            DbErrorKind::Mysql(e) => e.is_sentry_event(),
+            _ => true,
+        }
+    }
+
+    fn metric_label(&self) -> Option<String> {
+        match &self.kind {
+            DbErrorKind::Mysql(e) => e.metric_label(),
+            _ => None,
+        }
+    }
+}
+
 #[derive(Debug, Error)]
 enum DbErrorKind {
     #[error("{}", _0)]
@@ -56,7 +79,7 @@ impl From<DbError> for TokenserverError {
         TokenserverError {
             description: db_error.to_string(),
             context: db_error.to_string(),
-            backtrace: db_error.backtrace,
+            backtrace: db_error.backtrace.clone(),
             http_status: if db_error.status.is_server_error() {
                 // Use the status code from the DbError if it already suggests an internal error;
                 // it might be more specific than `StatusCode::SERVICE_UNAVAILABLE`
@@ -64,6 +87,7 @@ impl From<DbError> for TokenserverError {
             } else {
                 StatusCode::SERVICE_UNAVAILABLE
             },
+            source: Some(Box::new(db_error)),
             // An unhandled DbError in the Tokenserver code is an internal error
             ..TokenserverError::internal_error()
         }