firebase.json

{
  "hosting": {
    "target": "production",
    "public": ".",
    "ignore": [
      "firebase.json",
      "**/.*",
      "**/node_modules/**"
    ],
    "headers": [
      {
        "source": "**/*.@(eot|otf|ttf|ttc|woff|font.css)",
        "headers": [
          {
            "key": "Access-Control-Allow-Origin",
            "value": "*"
          }
        ]
      },
      {
        "source": "**/*.@(js|css)",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "max-age=604800"
          }
        ]
      },
      {
        "source": "**/*.@(jpg|jpeg|gif|png|mp4|webm)",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "max-age=604800"
          }
        ]
      },
      {
        "source": "404.html",
        "headers": [
          {
            "key": "Cache-Control",
            "value": "max-age=300"
          }
        ]
      }
    ]
  }
}