more cases for known connection errors we don't need debug info about

this logs a shorter message with just the error code
instead of the traceback

Author: minrk

lib/configproxy.js

@@ -425,15 +425,20 @@ class ConfigurableProxy extends EventEmitter {
     this.statsd.increment("requests." + code, 1);
     if (e) {
       // avoid stack traces on known not-our-problem errors:
-      // ECONNREFUSED (backend isn't there)
-      // ECONNRESET (backend is there, but didn't respond)
-      if (e.code === "ECONNRESET" || e.code === "ECONNREFUSED") {
-        errMsg = e.message;
-      } else {
-        // logging the error object shows a stack trace.
-        // Anything that gets here is an unknown error,
-        // so log more info.
-        errMsg = e;
+      // ECONNREFUSED, EHOSTUNREACH (backend isn't there)
+      // ECONNRESET, ETIMEDOUT (backend is there, but didn't respond)
+      switch (e.code) {
+        case "ECONNREFUSED":
+        case "ECONNRESET":
+        case "EHOSTUNREACH":
+        case "ETIMEDOUT":
+          errMsg = e.message;
+          break;
+        default:
+          // logging the error object shows a stack trace.
+          // Anything that gets here is an unknown error,
+          // so log more info.
+          errMsg = e;
       }
     }
     this.log.error("%s %s %s %s", code, req.method, req.url, errMsg);