PingCheck.ts

/*
 * Copyright IBM Corporation 2018
 *
 * 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.
 */

import { LivenessCheck } from '../HealthChecker';
import * as http from "http";

class PingCheck extends LivenessCheck {

    constructor(host: string, path = '', port = '80', method = 'HEAD' ) {
        let options = {
            hostname: host,
            port: port,
            path: path,
            method: method
        };

        let promise = () => new Promise<void>(function(resolve, reject) {
            const req = http.request(options, (res) => {
                res.on('data', () => {
                    //Ensures above promise is resolved
                })                
                res.on('end', () => {
                    resolve();
                });
            });
            req.on('error', (e) => {
                reject(new Error(`Failed to ping ${options.method}:${options.hostname}:${options.port}/${options.path}: ${e.message}`));
            });
            req.end();
        });
        super("PingCheck " + options.method + ":" + options.hostname + ":" + options.port + "/" + options.path, promise)
    }
}

export { PingCheck };