41 lines
1.6 KiB
JavaScript
41 lines
1.6 KiB
JavaScript
'use strict';
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exports = module.exports = {
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resolve,
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};
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const assert = require('assert'),
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constants = require('./constants.js'),
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dns = require('dns'),
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safe = require('safetydance'),
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_ = require('underscore');
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// a note on TXT records. It doesn't have quotes ("") at the DNS level. Those quotes
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// are added for DNS server software to enclose spaces. Such quotes may also be returned
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// by the DNS REST API of some providers
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async function resolve(hostname, rrtype, options) {
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assert.strictEqual(typeof hostname, 'string');
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assert.strictEqual(typeof rrtype, 'string');
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assert(options && typeof options === 'object');
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const defaultOptions = { server: '127.0.0.1', timeout: 5000 }; // unbound runs on 127.0.0.1
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const resolver = new dns.promises.Resolver();
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options = _.extend({ }, defaultOptions, options);
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// Only use unbound on a Cloudron
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if (constants.CLOUDRON) resolver.setServers([ options.server ]);
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// should callback with ECANCELLED but looks like we might hit https://github.com/nodejs/node/issues/14814
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const timerId = setTimeout(resolver.cancel.bind(resolver), options.timeout || 5000);
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const [error, result] = await safe(resolver.resolve(hostname, rrtype));
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clearTimeout(timerId);
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if (error && error.code === 'ECANCELLED') error.code = 'TIMEOUT';
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if (error) throw error;
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// when you query a random record, it errors with ENOTFOUND. But, if you query a record which has a different type
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// we sometimes get empty array and sometimes ENODATA. for TXT records, result is 2d array of strings
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return result;
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}
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