refactor: refs #6656 set proxy for test environment

.env.example

@@ -1 +1,2 @@
 TARGET='url del servidor local'
+PORT='puerto de acceso'

Dockerfile

@@ -30,3 +30,5 @@ COPY \
     index.html \
     clockIn.html \
     ./
+
+CMD ["node", "proxy.js"]

proxy.js

@@ -12,7 +12,7 @@ const apiProxy = createProxyMiddleware('/api', {
 app.use('/api', apiProxy);
 app.use('/', express.static(__dirname));
 
-const port = 4000;
+const port = process.env.PORT;
 app.listen(port, () => {
   console.log(`Server running on port: ${port}`);
 });