feat(ch07s02): Add readiness probe switch (#152)

.gitignore

@@ -69,3 +69,8 @@ nb-configuration.xml
 ## OS X
 ##########################
 .DS_Store
+
+##########################
+## JavaScript
+##########################
+node_modules/

probes/app.js

@@ -2,13 +2,12 @@ var express = require('express'),
   app = express();
 
 var port = process.env.PORT || process.env.OPENSHIFT_NODEJS_PORT || 8080,
-    ip   = process.env.IP   || process.env.OPENSHIFT_NODEJS_IP || '0.0.0.0';
+  ip = process.env.IP || process.env.OPENSHIFT_NODEJS_IP || '0.0.0.0',
+  healthy = true,
+  ready = true;
 
 var route = express.Router();
 
-// global var to track app health
-var healthy = true;
-
 app.use('/', route);
 
 // A route that says hello
@@ -17,11 +16,10 @@ route.get('/', function(req, res) {
 });
 
 // A route that returns readiness status
-// simulates readiness 30 seconds after start up
 route.get('/ready', function (req, res) {
   var now = Math.floor(Date.now() / 1000);
   var lapsed = now - started;
-      if (lapsed > 30) {
+  if (ready && (lapsed > 30)) {
     console.log('ping /ready => pong [ready]');
     res.send('Ready for service requests...\n');
   }
@@ -41,25 +39,30 @@ route.get('/healthz', function(req, res) {
   else {
     console.log('ping /healthz => pong [unhealthy]');
     res.status(503);
-      res.send('Error!. App not healthy!\n');
+    res.send('Error! App not healthy!\n');
   }
 });
 
 // This route handles switching the state of the app
 route.route('/flip').get(function (req, res) {
-
   var flag = req.query.op;
-        if (flag == "kill") {
-	  console.log('Received kill request. Changing app state to unhealthy...');
+  if (flag === 'kill-health') {
+    console.log('Received kill request for health probe.');
     healthy = false;
     res.send('Switched app state to unhealthy...\n');
-	}
-	else if (flag == "awaken") {
-	  console.log('Received awaken request. Changing app state to healthy...');
+  } else if (flag === "awaken-health") {
+    console.log('Received awaken request for health probe.');
     healthy = true;
     res.send('Switched app state to healthy...\n');
-	}
-	else {
+  } else if (flag === 'kill-ready') {
+    console.log('Received kill request for readiness probe.');
+    ready = false;
+    res.send('Switched app state to not ready...\n');
+  } else if (flag === 'awaken-ready') {
+    console.log('Received awaken request for readiness probe.');
+    ready = true;
+    res.send('Switched app state to ready...\n');
+  } else {
     res.send('Error! unknown flag...\n');
   }
 });

probes/package.json

@@ -9,6 +9,6 @@
   "author": "Red Hat Training",
   "license": "ASL",
   "dependencies": {
-    "express": "4.14.x"
+    "express": "4.17.x"
   }
 }