Add healthcheck container for OOM

Change-Id: Ie4719a0e4705901fd9d0fa3504696fbefc6c704a
Issue-ID: DCAEGEN2-461
Signed-off-by: Jack Lucas <jflucas@research.att.com>

1 files changed, 80 insertions, 0 deletions

diff --git a/healthcheck-container/healthcheck.js b/healthcheck-container/healthcheck.js
new file mode 100644
index 0000000..7555032
--- /dev/null
+++ b/healthcheck-container/healthcheck.js
@@ -0,0 +1,80 @@
+/*
+Copyright(c) 2018 AT&T Intellectual Property. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+
+You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing,
+software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and limitations under the License.
+*/
+
+//Expect ONAP and DCAE namespaces and Helm "release" name to be passed via environment variables
+// 
+const ONAP_NS = process.env.ONAP_NAMESPACE || 'default';
+const DCAE_NS = process.env.DCAE_NAMESPACE || 'default';
+const HELM_REL = process.env.HELM_RELEASE || '';
+
+const HEALTHY = 200;
+const UNHEALTHY = 500;
+const UNKNOWN = 503;
+
+const status = require('./get-status');
+const http = require('http');
+
+const isHealthy = function(summary) {
+	// Current healthiness criterion is simple--all deployments are ready
+	return summary.count && summary.ready && summary.count === summary.ready;
+};
+
+const checkHealth = function (callback) {
+	// Makes queries to Kubernetes and checks results
+	// If we encounter some kind of error contacting k8s (or other), health status is UNKNOWN (500)
+	// If we get responses from k8s but don't find all deployments ready, health status is UNHEALTHY (503)
+	// If we get responses from k8s and all deployments are ready, health status is HEALTHY (200)
+	// This could be a lot more nuanced, but what's here should be sufficient for R2 OOM healthchecking
+	status.getStatusNamespace(DCAE_NS, function(err, res, body) {
+		let ret = {status : UNKNOWN, body: [body]};
+		if (err) {
+			callback(ret);
+		}
+		else if (body.type && body.type === 'summary') {
+			if (isHealthy(body)) {
+				// All the DCAE components report healthy -- check Cloudify Manager
+				let cmDeployment = 'dcae-cloudify-manager';
+				if (HELM_REL.length > 0) {
+					cmDeployment = HELM_REL + '-' + cmDeployment;
+				}
+				status.getStatusSingle(ONAP_NS, cmDeployment, function (err, res, body){
+					ret.body.push(body);
+					if (err) {
+						callback(ret);
+					}
+					if (body.type && body.type === 'summary') {
+						ret.status = isHealthy(body) ? HEALTHY : UNHEALTHY;
+					}
+					callback(ret);
+				});
+			}
+			else {
+				callback(ret);
+			}
+		}
+	});
+};
+
+// Simple HTTP server--any incoming request triggers a health check
+const server = http.createServer(function(req, res) {
+	checkHealth(function(ret) {
+		console.log ((new Date()).toISOString() + ": " + JSON.stringify(ret));
+		res.statusCode = ret.status;
+		res.setHeader('Content-Type', 'application/json');
+		res.end(JSON.stringify(ret.body || {}), 'utf8');
+	});
+});
+server.listen(80);