From 9f680874c5aa15304c3ab3b942170a743287f87b Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Fri, 14 Mar 2025 17:33:48 +0100
Subject: [PATCH] Make the JSON logger more robust

We now ignore connection / write errors.
---
 src/libutil/logging.cc | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/src/libutil/logging.cc b/src/libutil/logging.cc
index 1d0d3fa2d..21f13d3c0 100644
--- a/src/libutil/logging.cc
+++ b/src/libutil/logging.cc
@@ -204,6 +204,7 @@ struct JSONLogger : Logger {
 
     struct State
     {
+        bool enabled = true;
     };
 
     Sync<State> _state;
@@ -216,8 +217,18 @@ struct JSONLogger : Logger {
 
         /* Acquire a lock to prevent log messages from clobbering each
            other. */
-        auto state(_state.lock());
-        writeLine(fd, line);
+        try {
+            auto state(_state.lock());
+            if (state->enabled)
+                writeLine(fd, line);
+        } catch (...) {
+            bool enabled = false;
+            std::swap(_state.lock()->enabled, enabled);
+            if (enabled) {
+                ignoreExceptionExceptInterrupt();
+                logger->warn("disabling JSON logger due to write errors");
+            }
+        }
     }
 
     void log(Verbosity lvl, std::string_view s) override