Return failed health checks with disabled file

config/environments/development.js.example

@@ -174,6 +174,7 @@ var config = {
       x: 0,
       y: 0
     }
+    ,disabled_file: 'pids/disabled'
 
     // Use this as a feature flags enabling/disabling mechanism
     ,enabledFeatures: {

config/environments/production.js.example

@@ -183,6 +183,7 @@ var config = {
       x: 0,
       y: 0
     }
+    ,disabled_file: 'pids/disabled'
 
     // Use this as a feature flags enabling/disabling mechanism
     ,enabledFeatures: {

config/environments/staging.js.example

@@ -183,6 +183,7 @@ var config = {
       x: 0,
       y: 0
     }
+    ,disabled_file: 'pids/disabled'
 
     // Use this as a feature flags enabling/disabling mechanism
     ,enabledFeatures: {

config/environments/test.js.example

@@ -172,6 +172,7 @@ var config = {
       x: 0,
       y: 0
     }
+    ,disabled_file: 'pids/disabled'
 
     // Use this as a feature flags enabling/disabling mechanism
     ,enabledFeatures: {

lib/cartodb/monitoring/health_check.js

@@ -42,7 +42,25 @@ HealthCheck.prototype.check = function(config, callback) {
     var mapnikXmlParams = config;
 
     step(
-        function getDBParams() {
+        function getManualDisable() {
+          disabled_file = global.environment.disabled_file;
+          fs.readFile(disabled_file, this);
+        },
+        function handleDisabledFile(err, data) {
+          var next = this;
+          if (err) {
+            return next();
+          }
+          if (!!data) {
+            err = new Error(data);
+            err.http_status = 503;
+            throw err;
+          }
+        },
+        function getDBParams(err) {
+            if (err) {
+              throw err;
+            }
             startTime = Date.now();
             self.metadataBackend.getAllUserDBParams(config.username, this);
         },

test/acceptance/health_check.js

@@ -5,6 +5,11 @@ var CartodbWindshaft = require(__dirname + '/../../lib/cartodb/cartodb_windshaft
 var serverOptions = require(__dirname + '/../../lib/cartodb/server_options')();
 var server = new CartodbWindshaft(serverOptions);
 
+var metadataBackend = {};
+var tilelive = {};
+var HealthCheck = require('../../lib/cartodb/monitoring/health_check');
+var healthCheck = new HealthCheck(metadataBackend, tilelive);
+
 suite('health checks', function () {
 
     function resetHealthConfig() {
@@ -71,4 +76,44 @@ suite('health checks', function () {
         );
     });
 
+    test('error if disabled file exists', function(done) {
+      var fs = require('fs');
+
+      readFileFn = fs.readFile
+      fs.readFile = function(filename, callback) {
+        callback(null, "Maintenance");
+      }   
+      
+      healthCheck.check(null, function(err, result) {
+        assert.equal(err.message, "Maintenance");
+        assert.equal(err.http_status, 503);
+        done();
+      }); 
+      
+      fs.readFile = readFileFn;
+    }); 
+
+    test('not err if disabled file does not exists', function(done) {
+      resetHealthConfig();
+
+      global.environment.disabled_file = '/tmp/ftreftrgtrccre';
+
+      assert.response(server,
+        healthCheckRequest,
+        {
+          status: 200
+        },
+        function (res, err) {
+          assert.ok(!err);
+
+          var parsed = JSON.parse(res.body);
+
+          assert.equal(parsed.enabled, true);
+          assert.equal(parsed.ok, true);
+
+          done();
+        }
+      );
+    }); 
+
 });