From a368230afab3a64517be462fe49e01210babd7ad Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sybren=20A=2E=20St=C3=BCvel?= <sybren@blender.org>
Date: Fri, 17 Jun 2022 17:13:32 +0200
Subject: [PATCH] Manager: fix race condition in logging of worker name/UUID

Instead of updating the logger in the context, just store a new logger
in a new sub-context.
---
 internal/manager/api_impl/worker_auth.go | 18 ++++++------------
 internal/manager/api_impl/zerolog.go     |  3 +--
 2 files changed, 7 insertions(+), 14 deletions(-)

diff --git a/internal/manager/api_impl/worker_auth.go b/internal/manager/api_impl/worker_auth.go
index 4dffaf09..f5e59634 100644
--- a/internal/manager/api_impl/worker_auth.go
+++ b/internal/manager/api_impl/worker_auth.go
@@ -9,7 +9,6 @@ import (
 	oapi_middle "github.com/deepmap/oapi-codegen/pkg/middleware"
 	"github.com/getkin/kin-openapi/openapi3filter"
 	"github.com/labstack/echo/v4"
-	"github.com/rs/zerolog"
 	"golang.org/x/crypto/bcrypt"
 
 	"git.blender.org/flamenco/internal/manager/persistence"
@@ -65,19 +64,14 @@ func requestWorkerStore(e echo.Context, w *persistence.Worker) {
 	req := e.Request()
 	reqCtx := context.WithValue(req.Context(), workerKey, w)
 
-	// Take copies now to avoid race conditions later.
-	wUUID := w.UUID
-	wName := w.Name
-
 	// Update the logger in this context to reflect the Worker.
-	l := zerolog.Ctx(reqCtx)
-	l.UpdateContext(func(c zerolog.Context) zerolog.Context {
-		return c.
-			Str("wUUID", wUUID).
-			Str("wName", wName)
-	})
+	logger := requestLogger(e).With().
+		Str("wUUID", w.UUID).
+		Str("wName", w.Name).
+		Logger()
 
-	e.SetRequest(req.WithContext(reqCtx))
+	newCtx := logger.WithContext(reqCtx)
+	e.SetRequest(req.WithContext(newCtx))
 }
 
 // requestWorker returns the Worker associated with this HTTP request, or nil if there is none.
diff --git a/internal/manager/api_impl/zerolog.go b/internal/manager/api_impl/zerolog.go
index 6cf055bd..e40741cc 100644
--- a/internal/manager/api_impl/zerolog.go
+++ b/internal/manager/api_impl/zerolog.go
@@ -5,10 +5,9 @@ package api_impl
 import (
 	"github.com/labstack/echo/v4"
 	"github.com/rs/zerolog"
-	"github.com/rs/zerolog/log"
 )
 
 func requestLogger(e echo.Context) zerolog.Logger {
-	logger := log.Ctx(e.Request().Context())
+	logger := zerolog.Ctx(e.Request().Context())
 	return *logger
 }