没有CORS解决方案对我有效…直到现在!

Not sure if anyone else ran into the same issue I did, but I set up CORS like 5 different ways from examples I found and nothing seemed to work. I set up a minimal example with Plunker to see if it was really a bug, but the example ran beautifully. I decided to check the firebase functions logs (found in the firebase console) to see if that could tell me anything. I had a couple errors in my node server code, not CORS related, that when I debugged released me of my CORS error message. I don't know why code errors unrelated to CORS returns a CORS error response, but it led me down the wrong rabbit hole for a good number of hours...

dr -如果没有CORS解决方案工作，检查您的firebase函数日志并调试任何错误

如果你不/不能使用cors插件，在处理函数中首先调用setCorsHeaders()函数也可以工作。

在回复时也使用respondSuccess/Error函数。

const ALLOWED_ORIGINS = ["http://localhost:9090", "https://sub.example.com", "https://example.com"]


// Set CORS headers for preflight requests
function setCorsHeaders (req, res) {
  var originUrl = "http://localhost:9090"


  if(ALLOWED_ORIGINS.includes(req.headers.origin)){
    originUrl = req.headers.origin
  }

  res.set('Access-Control-Allow-Origin', originUrl);
  res.set('Access-Control-Allow-Credentials', 'true');

  if (req.method === 'OPTIONS') {
    // Send response to OPTIONS requests
    res.set('Access-Control-Allow-Methods', 'GET,POST','PUT','DELETE');
    res.set('Access-Control-Allow-Headers', 'Bearer, Content-Type');
    res.set('Access-Control-Max-Age', '3600');
    res.status(204).send('');
  }
}

function respondError (message, error, code, res) {
  var response = {
    message: message,
    error: error
  }
  res.status(code).end(JSON.stringify(response));
}


function respondSuccess (result, res) {
  var response = {
    message: "OK",
    result: result
  }
  res.status(200).end(JSON.stringify(response));
}

通过“*”改变true对我来说很有用，所以它看起来是这样的:

const cors = require('cors')({ origin: "*" })

我尝试了这种方法，因为在一般情况下，这是响应头的设置方式:

'Access-Control-Allow-Origin', '*'

请注意，这将允许任何域调用您的端点，因此它是不安全的。

此外，你可以阅读更多关于文档的内容: https://github.com/expressjs/cors

Go into your Google Cloud Functions. You may have not seen this platform before, but it's how you'll fix this Firebase problem. Find the Firebase function you're searching for and click on the name. If this page is blank, you may need to search for Cloud Functions and select the page from the results. Find your function, click on the name. Go to the permissions tab. Click Add (to add user). Under new principles, type 'allUsers' -- it should autocomplete before you finish typing. Under select a role, search for Cloud Functions, then choose Invoker. Save. Wait a couple minutes.

这应该能解决问题。如果没有，就这样做，并在你的函数代码中添加一个CORS解决方案，比如:

  exports.sendMail = functions.https.onRequest((request, response) => {
  response.set("Access-Control-Allow-Origin", "*");
  response.send("Hello from Firebase!");
});

如果有像我这样的人:如果你想在同一个项目中调用云函数，你可以init firebase sdk并使用onCall方法。它会为你处理一切:

exports.newRequest = functions.https.onCall((data, context) => {
    console.log(`This is the received data: ${data}.`);
    return data;
})

像这样调用这个函数:

// Init the firebase SDK first    
const functions = firebase.functions();
const addMessage = functions.httpsCallable(`newRequest`);

Firebase文档:https://firebase.google.com/docs/functions/callable

如果你不能初始化SDK，以下是其他建议的精髓:

如果在默认位置使用firebase托管和主机，请选择“重写:https://firebase.google.com/docs/hosting/full-config#rewrites” 或者像krishnazden建议的那样使用CORS: https://stackoverflow.com/a/53845986/1293220

在devtool控制台中，同样的访问允许控制源错误，我找到了其他具有更现代语法的解决方案:

我的CORS问题是存储(不是RTDB也不是浏览器…)，然后我没有信用卡(正如上述解决方案所要求的那样)，我的无信用卡解决方案是:

安装gsutil: https://cloud.google.com/storage/docs/gsutil_install#linux-and-macos 创建cors。Json文件通过终端加载与gsutil

gsutil cors set cors.json gs://[ your-bucket ]/-1.appspot.com

https://firebase.google.com/docs/storage/web/download-files#cors_configuration