Apache apisix routing configuration

I am new to apache APISIX, I want to configure the routing in the Apache APISIX gateway. First I have followed the APISIX official document. In that document, they have used "httpbin.org:80" for the upstream server. and it works for me, If I set the upstream new upstream server which is run in my localhost(127.0.0.1) it does not work for me. it throws a bad gateway error(502)

If anyone knows the answer to fix this issue, please let me know.

{
    "methods": [
        "GET"
    ],
    "host": "example.com",
    "uri": "/anything/*",
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "httpbin.org:80": 1
        }
    }
}

The above routing configuration is working for me. Here is the API GATEWAY (http://127.0.0.1:9080/anything/*) routes the request to http://httpbin.org:80/anything/*)

{
    "methods": [
        "GET"
    ],
    "host": "example.com",
    "uri": "/anything/*",
    "upstream": {
        "type": "roundrobin",
        "nodes": {
            "127.0.0.1:3001": 1
        }
    }
}

In the above configuration, I have configured the routing to service and that service is running on my local machine, and that port is 30001. Now if I call the API (http://127.0.0.1:9080/anything/*) it does not route my request to the server (http://127.0.0.1:3001/anything/*), instead it throws a bad gateway error.

const http = require('http')

const hostname = '127.0.0.1'
const port = 3001

const server = http.createServer((req, res) => {
  res.statusCode = 200
  res.setHeader('Content-Type', 'text/plain')
  res.end('Hello World\n')
})

server.listen(port, hostname, () => {
  console.log(`Server running at http://${hostname}:${port}/`)
})

Here the above code is my backend server, which is running as an upstream server.

If you know the answer to debug the bad gateway exception, kindly let me know.

I have faced the exact issue.

I'm assuming you are deploying APISIX with docker-compose or docker (with is recommended in their official documentation).

The docker applications are running on a docker bridge network named apisix. This is why your localhost application is not reachable by APISIX.