@apolitical/server/src/loaders/probes.loader.js

Node.js module to encapsulate Apolitical's express server setup

'use strict';

module.exports = ({ config, healthService }) => {
  const { HEALTH, LIVENESS, READINESS } = config.ENDPOINTS.PROBES;
  const { API, UI } = config.SERVER.PROBES_OPTIONS;

  function buildPrefix({ prefix }) {
    let result = '';
    if (prefix) {
      if (API.ALLOWED_PREFIXES.some((allowedPrefix) => prefix.includes(allowedPrefix))) {
        result = `${API.PREFIX_PATH}/${prefix}`;
      } else if (UI.ALLOWED_PREFIXES.some((allowedPrefix) => prefix.includes(allowedPrefix))) {
        result = `${UI.PREFIX_PATH}/${prefix}`;
      } else {
        result = prefix;
      }
    }
    return result;
  }

  return function load(app, { probes }) {
    if (probes) {
      const { readinessCheck, livenessCheck } = probes;
      // Overwrite checks when defined
      if (readinessCheck) {
        healthService.registerReadiness(readinessCheck);
      }
      if (livenessCheck) {
        healthService.registerLiveness(livenessCheck);
      }
      // Build base URL
      const probesPath = buildPrefix(probes);
      // Load probes endpoints
      app.get(`${probesPath}${HEALTH}`, healthService.healthEndpoint());
      app.get(`${probesPath}${READINESS}`, healthService.readinessEndpoint());
      app.get(`${probesPath}${LIVENESS}`, healthService.livenessEndpoint());
    }
  };
};