Do not validate SSL cert in Keystone health check

This commit turns off SSL certificate validation for the
Keystone Health check.

Change-Id: I42bdc18a4668baf48ac26614b5301cb10cdd71fa
Story: 2001093
Task: 4754

server/healthcheck/index.js

@@ -21,6 +21,7 @@ module.exports = function healthcheck(plugin, server) {
   const config = server.config();
   const keystoneUrl = util.keystoneUrl(config);
   const request = getRequest();
+  const requestParams = getRequestParams();
 
   server.log(['keystone', 'healthcheck', 'debug'], `keystone url is ${keystoneUrl}`);
 
@@ -41,11 +42,8 @@ module.exports = function healthcheck(plugin, server) {
 
   function check() {
     return new Promise((resolve, reject)=> {
-      const req = request({
-        hostname: getHostname(),
-        port    : getPort(),
-        method  : 'GET'
-      }, (res)=> {
+      const req = request(
+      requestParams, (res)=> {
         const statusCode = res.statusCode;
         if (statusCode >= 400) {
           plugin.status.red('Unavailable');
@@ -115,4 +113,19 @@ module.exports = function healthcheck(plugin, server) {
     return required.request;
   }
 
+  function getRequestParams() {
+    let params;
+
+    params = {
+      hostname: getHostname(),
+      port    : getPort(),
+      method  : 'GET'
+    };
+    if (util.startsWith(keystoneUrl, 'https')) {
+      params.rejectUnauthorized = false;
+    }
+
+    return params;
+  }
+
 };