kubernetes-probes

kubernetes-probes

Library for an express listener on specified port to expose an http probe endpoint that kubelet can use to check container status.

Usage

var k8sProbes = require('kubernetes-probes');
k8sProbes.addReadinessFunction(alive);
k8sProbes.addLivenessFunction(ready);
k8sProbes.listen(80);
//
// Readiness function
var ready = function(cb) {
    cb(true, "I am ready.");
};
//
// Liveness function
var alive = function(cb) {
    cb(true, "I am alive.");
};

Dependencies

• Express

API

• addReadinessFunction(alive, name)
  • alive - [REQUIRED] - function(cb). Called by kubernetes-probes when kubernetes requests a liveness probe. If this function is not defined, kubernetes-probes response will be "liveness function undefined." with status 400.
    • cb - [REQUIRED] - function(isAlive, message). Called to return liveness state to kubernetes-probes.
      • isAlive - [REQUIRED] - boolean. TRUE indicates alive, response status is 200. FALSE indicates not alive, response status is 400.
      • message - [OPTIONAL] - string. returned in response to probe.
        • default if isAlive TRUE - "alive".
        • default if isAlive FALSE - "dead".
  • name - [OPTIONAL] - string. Name of this particular aspect of being ready. Default is "All".
• addLivenessFunction(ready, name)
  • ready - [REQUIRED] - function(cb). Called by kubernetes-probes when kubernetes requests a readiness probe. If this function is not defined, kubernetes-probes response will be "readiness function undefined." with status 400.
    • cb - [REQUIRED] - function(isReady, message). Called to return liveness state to kubernetes-probes.
      • isReady - [REQUIRED] - boolean. TRUE indicates ready, response status is 200. FALSE indicates not ready, response status is 400.
      • message - [OPTIONAL] - string. returned in response to probe.
        • default if isAlive TRUE - "ready".
        • default if isAlive FALSE - "not ready".
  • name - [OPTIONAL] - string. Name of this particular aspect of being lively. Default is "All".
• listen(port)
  • port - [REQUIRED] - integer. kubernetes-probes will start listening on this port.