oracle-ldap-search.js

/* A simple module to query an OID (Oracle Internet Directory) server in order to
 * look up the full connection string for a given database name.
 */

var ldap = require('ldapjs');

module.exports.byAlias = function(dbAlias, callback) {
    var client = ldap.createClient({
        url: 'ldap://oid:123/',
        timeout: "2000", // LDAP operations timeout (milliseconds)
        connectTimeout: "5000", // TCP connection timeout (milliseconds)
        logLevel: 'trace'
    });

    var opts = {
        scope: 'base', // Return only the exact object, no sub-objects
        attributes: ['orclnetdescstring'], // Return only these attributes
        // NON-standard in ldapjs.  See this patch: https://github.com/mcavage/node-ldapjs/issues/134
        //derefAliases: 'always' // LDAP server-side dereference of alias entries
    };

    var username = '', password = '';

    client.on('error', function(err){
        console.log("Client experienced an error.");
    });

    client.on('timeout', function(err){
        console.log("Client timed out.");
        // Unbind at the first operation timeout. Normally you wouldn't do this, but we're only
        // doing one search, and giving up if it doesn't work.
        client.unbind();
    });

    client.on('connectTimeout', function(err){
        console.log("Connection timed out.");
    });

    client.bind(username, password, function (err) {
        if (err) {
            callback(err, null);
            return;
        }

        var onUnbind = function(err) {/*TODO handle error*/};
        var searchBase = 'CN=' + dbAlias + ',CN=OracleContext,DC=ora';

        client.search(searchBase, opts, function (err, res) {
            if (err) {
                callback(err, null);
                client.unbind(onUnbind);
                return;
            }

            var connectionStr = null;
            // Return the first valid ldap entry without delay, then ignore the rest (if any).
            res.on('searchEntry', function (entry) {
                if (!connectionStr && entry.object && entry.object.orclnetdescstring) {
                    connectionStr = entry.object.orclnetdescstring;
                    callback(null, connectionStr);
                }
            });
            // Docs say: "Note that the error event will only be for client/TCP errors, not LDAP error codes"
            res.on('error', function(err) {
                callback(err, null);
                client.unbind(onUnbind);
            });
            res.on('end', function (result) {
                //TODO verify result.status === 0, which indicates success
                client.unbind(onUnbind);
            });
        });
    });
};