firebase.json

{
  "hosting": {
    "public": "build",
    "rewrites": [
      {
        "source": "**",
        "destination": "/index.html"
      }
    ],
    "ignore": [
      "firebase.json",
      "**/.*",
      "**/node_modules/**"
    ],
    "headers": [{
      "source" : "**",
      "headers" : [{
        "key" : "Cache-Control",
        "value" : "max-age=172800"
      }]
    }]
  }
}