TUN-3470: Replace in-house logger calls with zerolog

vendor/github.com/rs/zerolog/ctx.go

@@ -0,0 +1,48 @@
+package zerolog
+
+import (
+	"context"
+)
+
+var disabledLogger *Logger
+
+func init() {
+	SetGlobalLevel(TraceLevel)
+	l := Nop()
+	disabledLogger = &l
+}
+
+type ctxKey struct{}
+
+// WithContext returns a copy of ctx with l associated. If an instance of Logger
+// is already in the context, the context is not updated.
+//
+// For instance, to add a field to an existing logger in the context, use this
+// notation:
+//
+//     ctx := r.Context()
+//     l := zerolog.Ctx(ctx)
+//     l.UpdateContext(func(c Context) Context {
+//         return c.Str("bar", "baz")
+//     })
+func (l *Logger) WithContext(ctx context.Context) context.Context {
+	if lp, ok := ctx.Value(ctxKey{}).(*Logger); ok {
+		if lp == l {
+			// Do not store same logger.
+			return ctx
+		}
+	} else if l.level == Disabled {
+		// Do not store disabled logger.
+		return ctx
+	}
+	return context.WithValue(ctx, ctxKey{}, l)
+}
+
+// Ctx returns the Logger associated with the ctx. If no logger
+// is associated, a disabled logger is returned.
+func Ctx(ctx context.Context) *Logger {
+	if l, ok := ctx.Value(ctxKey{}).(*Logger); ok {
+		return l
+	}
+	return disabledLogger
+}