Kubernetes HTTP liveness probe fails with "connection refused" even though URL works without it

For anyone interested I've managed to solve this issue.

I was getting a 301 redirect response from Wordpress due to Wordpress forcing my domain name example.com. Solved this issue by disabling Wordpress canonical redirection feature for the specific request http://POD_IP:8080/index.php.

Here's how:

Added the Pod IP address as an environment variable:

- name: K8S_POD_IP  valueFrom:    fieldRef:      fieldPath: status.podIP

Created a Wordpress plugin with a custom redirect_canonical filter that prevents Wordpress from redirecting http://POD_IP:8080/index.php:

<?php/** * Plugin Name: Kubernetes Liveness Probe Exception */add_filter('redirect_canonical', function($redirect_url, $requested_url) {    $K8S_POD_IP = getenv('K8S_POD_IP');    $LIVENESS_URL = "http://" . $K8S_POD_IP . ":8080/index.php";    if ($requested_url == $LIVENESS_URL) {        return $requested_url;    }    return $redirect_url;}, 10, 2);

10.244.3.1 - - [11/Dec/2019:06:39:18 +0000] "GET /index.php HTTP/1.1" 301 264 "-" "kube-probe/1.16"

You're getting a 301 redirect response from Apache. You need to be getting a 2xx to be considered a success.

To check what path it's redirecting you to try curl --location --verbose http://url/index.php

If you can't figure out a way around Apache or Wordpress's redirection, you could consider a tcpSocket probe rather than httpGet

I'd think WP redirects you to a “clean” url of /. Remove the index.php part