Using Axios to communicate between pods in a Kubernetes cluster

Question

I'm trying to get pods in a cluster to communicate using a REST API. Our services are Node.js-based. We formerly used the request networking package, but since it is now deprecated, we are migrating to the Axios network package.

The error I'm currently getting is:

tunneling socket could not be established, cause=connect ECONNREFUSED 127.0.0.1:443

When we were using the request package, we would send a network request with the following command:

request({
  'url': 'https://other-service:8000/api/endpoint',
  'json': true,
  'method', 'post',
  'body': data,
  'auth': {
    'username': '<username>',
    'password': '<password>',
    sendImmediately: true
  },
  'cert': certificate,
  'key': privateKey,
  'strictSSL': false,
  'headers': {
    'username': '<username>'
  }
});

Now, with Axios, the command we issue is:

axios({
  url: 'https://other-service:8000/api/endpoint',
  method: 'post',
  responseType: 'json',
  headers: {
    'username': '<username>'
  },
  auth: {
    'username': '<username>',
    'password': '<password>',
  },
  data: data,
  httpsAgent = tunnel.httpsOverHttps({
    key: privateKey,
    cert: certificate
  }
});

We are now getting the tunneling error:

tunneling socket could not be established, cause=connect ECONNREFUSED 127.0.0.1:443

I'm guessing the issue is related to where the tunnel package is attempting to validate the certificate, because if I comment out the line containing httpsAgent, I then get an error saying the certificate has expired.

Any help would be greatly appreciated.