count.js

#!/usr/bin/env node

// Copyright (c) 2015 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
'use strict';

var ClusterManager = require('./lib/cluster.js');
var program = require('commander');

function main() {
    program
        .description('Count members')
        .option('-h --hosts', 'Count of hosts')
        .option('-m --members', 'Count of members')
        .option('-p --partitions', 'Count of partitions')
        .option('--tchannel-v1')
        .usage('[options] <discoveryUri>');
    program.parse(process.argv);

    var discoveryUri = program.args[0];

    if (!discoveryUri) {
        console.error('Error: discoveryUri is required');
        process.exit(1);
    }

    if (!program.hosts && !program.members && !program.partitions) {
        console.error('Error: one of hosts, members or partitions is required');
        process.exit(1);
    }

    var clusterManager = new ClusterManager({
        useTChannelV1: program.tchannelV1,
        discoveryUri: discoveryUri
    });
    clusterManager.fetchStats(function onStats(err) {
        if (err) {
            console.error('Error: ' + err.message);
            process.exit(1);
        }

        var partitionCount = clusterManager.getPartitionCount();
        if (program.partitions) {
            console.log(partitionCount);
            clusterManager.printConnectionErrorMsg();
            process.exit(0);
        }

        if (partitionCount > 1) {
            console.error('Error: cluster is partitioned. An accurate count cannot be provided.');
            process.exit(1);
        }

        var cluster = clusterManager.getClusterAt(0);

        if (!cluster) {
            console.error('Error: no members in the cluster could be reached');
            process.exit(1);
        }

        if (program.members) {
            console.log(cluster.getNodeCount());
            clusterManager.printConnectionErrorMsg();
            process.exit();
        }

        if (program.hosts) {
            console.log(cluster.getHostCount());
            clusterManager.printConnectionErrorMsg();
            process.exit();
        }
    });
}

if (require.main === module) {
    main();
}