Move user ID handling to userid package

internal/userid/userid.go

@@ -0,0 +1,20 @@
+package userid
+
+import "context"
+
+type userIDKey struct{}
+
+// NewContext returns a new context with the given user ID added to the
+// context.
+// TODO(hs): this doesn't seem to be used / set currently; implement
+// when/where it makes sense.
+func NewContext(ctx context.Context, userID string) context.Context {
+	return context.WithValue(ctx, userIDKey{}, userID)
+}
+
+// FromContext returns the user ID from the context if it exists
+// and is not empty.
+func FromContext(ctx context.Context) (string, bool) {
+	v, ok := ctx.Value(userIDKey{}).(string)
+	return v, ok && v != ""
+}

logging/handler.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/sirupsen/logrus"
 	"github.com/smallstep/certificates/internal/requestid"
+	"github.com/smallstep/certificates/internal/userid"
 )
 
 // LoggerHandler creates a logger handler
@@ -60,7 +61,7 @@ func (l *LoggerHandler) writeEntry(w ResponseLogger, r *http.Request, t time.Tim
 	if v, ok := requestid.FromContext(ctx); ok {
 		requestID = v
 	}
-	if v, ok := GetUserID(ctx); ok && v != "" {
+	if v, ok := userid.FromContext(ctx); ok {
 		userID = v
 	}