Gravitee - Can’t connect to API inside docker and internal host

I’ve successfully set up Gravitee 4.2 inside my Docker containers following the official instructions in the docs. Everything seems to be working fine when I use an external API (not on localhost), such as https://catfact.ninja/fact as a gateway.

However, I’m encountering an issue when I try to point the endpoints to either another Docker container running or to an app on my local machine. The API Gateway consistently returns a “502 Bad Gateway” error.

I’ve attempted to use Bash inside the API-gateway container to curl to the container or app running on my local machine, but does not work, I can ping the machine, but when I try to use this command: curl -X GET 127.0.0.1:3000 the server does not respond. I’ve tried various endpoint configurations, including:

127.0.0.1:3000
host.docker.internal:3000
localhost:3000
{container_ip}:3000

But none of these configurations seem to resolve the issue.

I’m wondering if there’s something specific I need to do to make this work. Any guidance would be greatly appreciated.

I’m attempting to use Gravitee as gateway for container running on port 3000 (it’s a backend server that exposing an API that return JSON). I aim to utilize the gateway on port 8082 with the following URL format: http://localhost:8082/message-nifi. The adjacent URL is intended to act as gateway to the API of the container running on port 3000. Here is my export JSON API: https://drive.google.com/file/d/1o-RMhgJTqc-0eDWNNsy9bz5YO80txShn/view?usp=drive_link

As you are running a docker-compose, you need to use the service name as the host.

Let's say your backend running on port 3000 is named my_service, you will need to use http://my_service:3000 as a backend.