Give a short description/introduction When calling a function from a frontend application in a browser, you may receive an error about missing CORS headers. Here's how you can allow cross-origin requests to a Python function
This example assumes you are familiar with how serverless functions work. If needed, you can check Scaleway's official documentation
This example uses the Scaleway Serverless Framework Plugin. Please set up your environment with the requirements stated in the Scaleway Serverless Framework Plugin before trying out the example.
State the context of the example This example shows how to handle preflight CORS requests that will be sent by a browser when invoking a function. The example uses totally permissive, open CORS, you will may want to modify this to make it more secure.
State what the function does The function of the example is allowing most CORS requests. For more documentation on how to control access for CORS requests, see HTTP response headers
Once your environment is set up, you can run:
npm install
serverless deployUpdate with the tests to run for your example Then, from the given URL, you can run:
# Options request
curl -i -X OPTIONS <function URL>
# Get request
curl -i -X GET <function URL>Update with the expected output The result should be similar to:
HTTP/2 200
access-control-allow-headers: *
access-control-allow-methods: *
access-control-allow-origin: *
content-length: 21
content-type: text/plain
date: Tue, 17 Jan 2023 14:02:46 GMT
server: envoy
x-envoy-upstream-service-time: 222
This is checking CORS%You can also check the result of your function in a browser. It should be "This is checking CORS".