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Using default Docker network on MacOS: proxy React requests to Flask container

I am working on configuring the proxy requests from my React app to my Flask app. As my setup is now, React is throwing the error:
Proxy error: Could not proxy request /flask_endpoint from localhost:3000 to http://pathways_api_1:5000. See for more information (ECONNREFUSED).

I read in the docker networking documentation that within the default network, you must refer to the name of the container as the prefix. Therefore, I include the line:
"proxy": "http://pathways_api_1:5000" in my package.json, as pathways_api_1 is the name of the backend container according to the docker network inspect command.

Here is a snapshot of my docker network: “Containers”: {
“0ad70bf6b1c70993cf960416fe93596913954179ec8d5e31a08115896445029e”: {
“Name”: “pathways_client_1”,
“EndpointID”: “d5f5c9fedd4d0dcd581aeee29d97ecc8e7a6623331454f999308e93dc847d597”,
“MacAddress”: “02:42:ac:12:00:03”,
“IPv4Address”: “”,
“IPv6Address”: “”
“0fd9948ee7d3b1e242d56852b05cb2d88dab9e4000fa2b4f685bcd9950abb84e”: {
“Name”: “pathways_api_1”,
“EndpointID”: “c9826edfc750eb65d1a7b0ed95bb7d01da44344bbe730b2c61ccc5e2d10f2a24”,
“MacAddress”: “02:42:ac:12:00:02”,
“IPv4Address”: “”,
“IPv6Address”: “”

Additionally, I am using the following docker-compose.yml:

version: ‘3.7’
context: ./react-app
dockerfile: Dockerfile
tty: true
- “3000:3000”
- ./react-app:/app
- /app/node_modules

context: ./react-app/api
dockerfile: Dockerfile
- “5000:5000”

If anyone has any insight into what is going wrong here, that would be amazing. thank you for your assistance!

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You’re kindof on the right track, except thats not the correct names, its relative to the ones in docker-compose

so for you its just “api” or “client” :slight_smile:

I see. I have actually tried that, and I, unfortunately, got the same error: Proxy error: Could not proxy request /flask_endpoint from localhost:3000 to http://api:5000. See for more information (ECONNREFUSED). Could there be something else that I am missing? Thanks for your help!

Is the application listning on port 5000?
can you from the client container, ping the api container?
(docker exec -ti pathways_client_1 ping api)

Thanks for your help! I was able to resolve the issue. It turns out the way I was making Axios requests with react had to be tweaked slightly to work with docker. I needed to use syntax like axios post http://api/backend_endpoint rather than axios post backend_endpoint It turns out the latter only worked on my local network.