Support configurable log visibility in local-backend (#34060)

Manually confirmed that it works! Command line flag affects
log visibility correctly.

GitOrigin-RevId: 6e9d27f5b60b7a54be3743a5d730a33f0d7273d4

crates/application/src/log_visibility.rs

@@ -19,16 +19,24 @@ pub trait LogVisibility<RT: Runtime>: Send + Sync {
     ) -> anyhow::Result<bool>;
 }
 
-pub struct AllowLogging;
+pub struct RedactLogsToClient {
+    redact: bool,
+}
+
+impl RedactLogsToClient {
+    pub fn new(redact: bool) -> Self {
+        Self { redact }
+    }
+}
 
 #[async_trait]
-impl<RT: Runtime> LogVisibility<RT> for AllowLogging {
+impl<RT: Runtime> LogVisibility<RT> for RedactLogsToClient {
     async fn should_redact_logs_and_error(
         &self,
         _tx: &mut Transaction<RT>,
         _identity: Identity,
         _allowed_visibility: AllowedVisibility,
     ) -> anyhow::Result<bool> {
-        Ok(false)
+        Ok(self.redact)
     }
 }

crates/application/src/test_helpers.rs

@@ -108,7 +108,7 @@ use crate::{
         SchemaStatus,
         StartPushRequest,
     },
-    log_visibility::AllowLogging,
+    log_visibility::RedactLogsToClient,
     scheduled_jobs::ScheduledJobExecutor,
     Application,
 };
@@ -275,7 +275,7 @@ impl<RT: Runtime> ApplicationTestExt<RT> for Application<RT> {
             Arc::new(persistence.clone()),
             actions,
             Arc::new(NoopLogSender),
-            Arc::new(AllowLogging),
+            Arc::new(RedactLogsToClient::new(false)),
             Arc::new(ApplicationAuth::new(
                 kb.clone(),
                 Arc::new(NullAccessTokenAuth),

crates/local_backend/src/config.rs

@@ -86,6 +86,15 @@ pub struct LocalConfig {
     /// A tag to identify the self-hosted instance.
     #[clap(long, hide = true, default_value = "self-host")]
     pub beacon_tag: String,
+
+    /// If set, logs will be redacted from clients. Set this on production
+    /// deployments, to prevent information like stacktraces of serverside
+    /// code from being leaked to clients.
+    ///
+    /// On development deployments, it can be helpful to have this information
+    /// reach the client for debugging purposes.
+    #[clap(long, default_value = "false")]
+    pub redact_logs_to_client: bool,
 }
 
 impl fmt::Debug for LocalConfig {

crates/local_backend/src/lib.rs

@@ -19,7 +19,7 @@ use ::storage::{
 };
 use application::{
     api::ApplicationApi,
-    log_visibility::AllowLogging,
+    log_visibility::RedactLogsToClient,
     Application,
     QueryCache,
 };
@@ -246,7 +246,7 @@ pub async fn make_app(
         persistence,
         actions,
         Arc::new(NoopLogSender),
-        Arc::new(AllowLogging),
+        Arc::new(RedactLogsToClient::new(config.redact_logs_to_client)),
         Arc::new(ApplicationAuth::new(
             key_broker.clone(),
             Arc::new(NullAccessTokenAuth),