Add healthcheck container for OOM

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

1 files changed, 109 insertions, 0 deletions

diff --git a/healthcheck-container/get-status.js b/healthcheck-container/get-status.js
new file mode 100644
index 0000000..2ed1d3d
--- /dev/null
+++ b/healthcheck-container/get-status.js
@@ -0,0 +1,109 @@
+/*
+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.
+*/
+
+/*
+ * Query Kubernetes for status of deployments and extract readiness information
+ */
+
+const fs = require('fs');
+const request = require('request');
+
+const K8S_CREDS = '/var/run/secrets/kubernetes.io/serviceaccount';
+const K8S_API = 'https://kubernetes.default.svc.cluster.local/';	// Full name to match cert for TLS
+const K8S_PATH = 'apis/apps/v1beta2/namespaces/';
+
+//Get token and CA cert
+const ca = fs.readFileSync(K8S_CREDS + '/ca.crt');
+const token = fs.readFileSync(K8S_CREDS + '/token');
+
+const summarizeDeploymentList = function(list) {
+	// list is a DeploymentList object returned by k8s
+	// Individual deployments are in the array 'items'
+	
+	let ret = 
+	{
+		type: "summary",
+		count: 0,
+		ready: 0,
+		items: []
+	};
+	
+	// Extract readiness information
+	for (let deployment of list.items) {
+		ret.items.push(
+			{
+				name: deployment.metadata.name,
+				ready: deployment.status.readyReplicas || 0,
+				unavailable: deployment.status.unavailableReplicas || 0
+			}
+		);
+		ret.count ++;
+		ret.ready = ret.ready + (deployment.status.readyReplicas || 0);
+	}
+	
+	return ret;
+};
+
+const summarizeDeployment = function(deployment) {
+	// deployment is a Deployment object returned by k8s
+	// we make it look enough like a DeploymentList object to
+	// satisfy summarizeDeploymentList
+	return summarizeDeploymentList({items: [deployment]});
+};
+
+const queryKubernetes = function(path, callback) {
+	// Make request to Kubernetes
+	
+	const options = {
+		url: K8S_API + path,
+		ca : ca,
+		headers: {
+			Authorization: 'bearer ' + token
+		},
+		json: true
+	};
+	console.log ("request url: " + options.url);
+	request(options, function(error, res, body) {
+		console.log ("status: " + (res && res.statusCode) ? res.statusCode : "NONE");
+		if (error) {
+			console.log("error: " + error);
+		}
+		callback(error, res, body);
+	});
+};
+
+const getStatus = function(path, extract, callback) {
+	// Get info from k8s and extract readiness info
+	queryKubernetes(path, function(error, res, body) {
+		let ret = body;
+		if (!error && res && res.statusCode === 200) {
+			ret = extract(body);
+		}
+		callback (error, res, ret);
+	});
+};
+
+exports.getStatusNamespace = function (namespace, callback) {
+	// Get readiness information for all deployments in namespace
+	const path = K8S_PATH + namespace + '/deployments';
+	getStatus(path, summarizeDeploymentList, callback);
+};
+
+exports.getStatusSingle = function (namespace, deployment, callback) {
+	// Get readiness information for a single deployment
+	const path = K8S_PATH + namespace + '/deployments/' + deployment;
+	getStatus(path, summarizeDeployment, callback);
+};
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