diff options
Diffstat (limited to 'frontend-old/node_modules/@grpc/grpc-js/src/resolver-dns.ts')
| -rw-r--r-- | frontend-old/node_modules/@grpc/grpc-js/src/resolver-dns.ts | 412 |
1 files changed, 0 insertions, 412 deletions
diff --git a/frontend-old/node_modules/@grpc/grpc-js/src/resolver-dns.ts b/frontend-old/node_modules/@grpc/grpc-js/src/resolver-dns.ts deleted file mode 100644 index 31e0d0b..0000000 --- a/frontend-old/node_modules/@grpc/grpc-js/src/resolver-dns.ts +++ /dev/null @@ -1,412 +0,0 @@ -/* - * Copyright 2019 gRPC authors. - * - * 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 { - Resolver, - ResolverListener, - registerResolver, - registerDefaultScheme, -} from './resolver'; -import * as dns from 'dns'; -import * as util from 'util'; -import { extractAndSelectServiceConfig, ServiceConfig } from './service-config'; -import { Status } from './constants'; -import { StatusObject } from './call-interface'; -import { Metadata } from './metadata'; -import * as logging from './logging'; -import { LogVerbosity } from './constants'; -import { SubchannelAddress, TcpSubchannelAddress } from './subchannel-address'; -import { GrpcUri, uriToString, splitHostPort } from './uri-parser'; -import { isIPv6, isIPv4 } from 'net'; -import { ChannelOptions } from './channel-options'; -import { BackoffOptions, BackoffTimeout } from './backoff-timeout'; - -const TRACER_NAME = 'dns_resolver'; - -function trace(text: string): void { - logging.trace(LogVerbosity.DEBUG, TRACER_NAME, text); -} - -/** - * The default TCP port to connect to if not explicitly specified in the target. - */ -export const DEFAULT_PORT = 443; - -const DEFAULT_MIN_TIME_BETWEEN_RESOLUTIONS_MS = 30_000; - -const resolveTxtPromise = util.promisify(dns.resolveTxt); -const dnsLookupPromise = util.promisify(dns.lookup); - -/** - * Merge any number of arrays into a single alternating array - * @param arrays - */ -function mergeArrays<T>(...arrays: T[][]): T[] { - const result: T[] = []; - for ( - let i = 0; - i < - Math.max.apply( - null, - arrays.map(array => array.length) - ); - i++ - ) { - for (const array of arrays) { - if (i < array.length) { - result.push(array[i]); - } - } - } - return result; -} - -/** - * Resolver implementation that handles DNS names and IP addresses. - */ -class DnsResolver implements Resolver { - private readonly ipResult: SubchannelAddress[] | null; - private readonly dnsHostname: string | null; - private readonly port: number | null; - /** - * Minimum time between resolutions, measured as the time between starting - * successive resolution requests. Only applies to successful resolutions. - * Failures are handled by the backoff timer. - */ - private readonly minTimeBetweenResolutionsMs: number; - private pendingLookupPromise: Promise<dns.LookupAddress[]> | null = null; - private pendingTxtPromise: Promise<string[][]> | null = null; - private latestLookupResult: TcpSubchannelAddress[] | null = null; - private latestServiceConfig: ServiceConfig | null = null; - private latestServiceConfigError: StatusObject | null = null; - private percentage: number; - private defaultResolutionError: StatusObject; - private backoff: BackoffTimeout; - private continueResolving = false; - private nextResolutionTimer: NodeJS.Timeout; - private isNextResolutionTimerRunning = false; - private isServiceConfigEnabled = true; - private returnedIpResult = false; - constructor( - private target: GrpcUri, - private listener: ResolverListener, - channelOptions: ChannelOptions - ) { - trace('Resolver constructed for target ' + uriToString(target)); - const hostPort = splitHostPort(target.path); - if (hostPort === null) { - this.ipResult = null; - this.dnsHostname = null; - this.port = null; - } else { - if (isIPv4(hostPort.host) || isIPv6(hostPort.host)) { - this.ipResult = [ - { - host: hostPort.host, - port: hostPort.port ?? DEFAULT_PORT, - }, - ]; - this.dnsHostname = null; - this.port = null; - } else { - this.ipResult = null; - this.dnsHostname = hostPort.host; - this.port = hostPort.port ?? DEFAULT_PORT; - } - } - this.percentage = Math.random() * 100; - - if (channelOptions['grpc.service_config_disable_resolution'] === 1) { - this.isServiceConfigEnabled = false; - } - - this.defaultResolutionError = { - code: Status.UNAVAILABLE, - details: `Name resolution failed for target ${uriToString(this.target)}`, - metadata: new Metadata(), - }; - - const backoffOptions: BackoffOptions = { - initialDelay: channelOptions['grpc.initial_reconnect_backoff_ms'], - maxDelay: channelOptions['grpc.max_reconnect_backoff_ms'], - }; - - this.backoff = new BackoffTimeout(() => { - if (this.continueResolving) { - this.startResolutionWithBackoff(); - } - }, backoffOptions); - this.backoff.unref(); - - this.minTimeBetweenResolutionsMs = - channelOptions['grpc.dns_min_time_between_resolutions_ms'] ?? - DEFAULT_MIN_TIME_BETWEEN_RESOLUTIONS_MS; - this.nextResolutionTimer = setTimeout(() => {}, 0); - clearTimeout(this.nextResolutionTimer); - } - - /** - * If the target is an IP address, just provide that address as a result. - * Otherwise, initiate A, AAAA, and TXT lookups - */ - private startResolution() { - if (this.ipResult !== null) { - if (!this.returnedIpResult) { - trace('Returning IP address for target ' + uriToString(this.target)); - setImmediate(() => { - this.listener.onSuccessfulResolution( - this.ipResult!, - null, - null, - null, - {} - ); - }); - this.returnedIpResult = true; - } - this.backoff.stop(); - this.backoff.reset(); - this.stopNextResolutionTimer(); - return; - } - if (this.dnsHostname === null) { - trace('Failed to parse DNS address ' + uriToString(this.target)); - setImmediate(() => { - this.listener.onError({ - code: Status.UNAVAILABLE, - details: `Failed to parse DNS address ${uriToString(this.target)}`, - metadata: new Metadata(), - }); - }); - this.stopNextResolutionTimer(); - } else { - if (this.pendingLookupPromise !== null) { - return; - } - trace('Looking up DNS hostname ' + this.dnsHostname); - /* We clear out latestLookupResult here to ensure that it contains the - * latest result since the last time we started resolving. That way, the - * TXT resolution handler can use it, but only if it finishes second. We - * don't clear out any previous service config results because it's - * better to use a service config that's slightly out of date than to - * revert to an effectively blank one. */ - this.latestLookupResult = null; - const hostname: string = this.dnsHostname; - /* We lookup both address families here and then split them up later - * because when looking up a single family, dns.lookup outputs an error - * if the name exists but there are no records for that family, and that - * error is indistinguishable from other kinds of errors */ - this.pendingLookupPromise = dnsLookupPromise(hostname, { all: true }); - this.pendingLookupPromise.then( - addressList => { - if (this.pendingLookupPromise === null) { - return; - } - this.pendingLookupPromise = null; - this.backoff.reset(); - this.backoff.stop(); - const ip4Addresses: dns.LookupAddress[] = addressList.filter( - addr => addr.family === 4 - ); - const ip6Addresses: dns.LookupAddress[] = addressList.filter( - addr => addr.family === 6 - ); - this.latestLookupResult = mergeArrays(ip6Addresses, ip4Addresses).map( - addr => ({ host: addr.address, port: +this.port! }) - ); - const allAddressesString: string = - '[' + - this.latestLookupResult - .map(addr => addr.host + ':' + addr.port) - .join(',') + - ']'; - trace( - 'Resolved addresses for target ' + - uriToString(this.target) + - ': ' + - allAddressesString - ); - if (this.latestLookupResult.length === 0) { - this.listener.onError(this.defaultResolutionError); - return; - } - /* If the TXT lookup has not yet finished, both of the last two - * arguments will be null, which is the equivalent of getting an - * empty TXT response. When the TXT lookup does finish, its handler - * can update the service config by using the same address list */ - this.listener.onSuccessfulResolution( - this.latestLookupResult, - this.latestServiceConfig, - this.latestServiceConfigError, - null, - {} - ); - }, - err => { - if (this.pendingLookupPromise === null) { - return; - } - trace( - 'Resolution error for target ' + - uriToString(this.target) + - ': ' + - (err as Error).message - ); - this.pendingLookupPromise = null; - this.stopNextResolutionTimer(); - this.listener.onError(this.defaultResolutionError); - } - ); - /* If there already is a still-pending TXT resolution, we can just use - * that result when it comes in */ - if (this.isServiceConfigEnabled && this.pendingTxtPromise === null) { - /* We handle the TXT query promise differently than the others because - * the name resolution attempt as a whole is a success even if the TXT - * lookup fails */ - this.pendingTxtPromise = resolveTxtPromise(hostname); - this.pendingTxtPromise.then( - txtRecord => { - if (this.pendingTxtPromise === null) { - return; - } - this.pendingTxtPromise = null; - try { - this.latestServiceConfig = extractAndSelectServiceConfig( - txtRecord, - this.percentage - ); - } catch (err) { - this.latestServiceConfigError = { - code: Status.UNAVAILABLE, - details: `Parsing service config failed with error ${ - (err as Error).message - }`, - metadata: new Metadata(), - }; - } - if (this.latestLookupResult !== null) { - /* We rely here on the assumption that calling this function with - * identical parameters will be essentialy idempotent, and calling - * it with the same address list and a different service config - * should result in a fast and seamless switchover. */ - this.listener.onSuccessfulResolution( - this.latestLookupResult, - this.latestServiceConfig, - this.latestServiceConfigError, - null, - {} - ); - } - }, - err => { - /* If TXT lookup fails we should do nothing, which means that we - * continue to use the result of the most recent successful lookup, - * or the default null config object if there has never been a - * successful lookup. We do not set the latestServiceConfigError - * here because that is specifically used for response validation - * errors. We still need to handle this error so that it does not - * bubble up as an unhandled promise rejection. */ - } - ); - } - } - } - - private startNextResolutionTimer() { - clearTimeout(this.nextResolutionTimer); - this.nextResolutionTimer = setTimeout(() => { - this.stopNextResolutionTimer(); - if (this.continueResolving) { - this.startResolutionWithBackoff(); - } - }, this.minTimeBetweenResolutionsMs).unref?.(); - this.isNextResolutionTimerRunning = true; - } - - private stopNextResolutionTimer() { - clearTimeout(this.nextResolutionTimer); - this.isNextResolutionTimerRunning = false; - } - - private startResolutionWithBackoff() { - if (this.pendingLookupPromise === null) { - this.continueResolving = false; - this.backoff.runOnce(); - this.startNextResolutionTimer(); - this.startResolution(); - } - } - - updateResolution() { - /* If there is a pending lookup, just let it finish. Otherwise, if the - * nextResolutionTimer or backoff timer is running, set the - * continueResolving flag to resolve when whichever of those timers - * fires. Otherwise, start resolving immediately. */ - if (this.pendingLookupPromise === null) { - if (this.isNextResolutionTimerRunning || this.backoff.isRunning()) { - if (this.isNextResolutionTimerRunning) { - trace('resolution update delayed by "min time between resolutions" rate limit'); - } else { - trace('resolution update delayed by backoff timer until ' + this.backoff.getEndTime().toISOString()); - } - this.continueResolving = true; - } else { - this.startResolutionWithBackoff(); - } - } - } - - /** - * Reset the resolver to the same state it had when it was created. In-flight - * DNS requests cannot be cancelled, but they are discarded and their results - * will be ignored. - */ - destroy() { - this.continueResolving = false; - this.backoff.reset(); - this.backoff.stop(); - this.stopNextResolutionTimer(); - this.pendingLookupPromise = null; - this.pendingTxtPromise = null; - this.latestLookupResult = null; - this.latestServiceConfig = null; - this.latestServiceConfigError = null; - this.returnedIpResult = false; - } - - /** - * Get the default authority for the given target. For IP targets, that is - * the IP address. For DNS targets, it is the hostname. - * @param target - */ - static getDefaultAuthority(target: GrpcUri): string { - return target.path; - } -} - -/** - * Set up the DNS resolver class by registering it as the handler for the - * "dns:" prefix and as the default resolver. - */ -export function setup(): void { - registerResolver('dns', DnsResolver); - registerDefaultScheme('dns'); -} - -export interface DnsUrl { - host: string; - port?: string; -} |