"use strict";
/*
* 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.
*
*/
Object.defineProperty(exports, "__esModule", { value: true });
exports.extractAndSelectServiceConfig = exports.validateServiceConfig = void 0;
/* This file implements gRFC A2 and the service config spec:
* https://github.com/grpc/proposal/blob/master/A2-service-configs-in-dns.md
* https://github.com/grpc/grpc/blob/master/doc/service_config.md. Each
* function here takes an object with unknown structure and returns its
* specific object type if the input has the right structure, and throws an
* error otherwise. */
/* The any type is purposely used here. All functions validate their input at
* runtime */
/* eslint-disable @typescript-eslint/no-explicit-any */
const os = require("os");
const load_balancer_1 = require("./load-balancer");
/**
* Recognizes a number with up to 9 digits after the decimal point, followed by
* an "s", representing a number of seconds.
*/
const TIMEOUT_REGEX = /^\d+(\.\d{1,9})?s$/;
/**
* Client language name used for determining whether this client matches a
* `ServiceConfigCanaryConfig`'s `clientLanguage` list.
*/
const CLIENT_LANGUAGE_STRING = 'node';
function validateName(obj) {
if (!('service' in obj) || typeof obj.service !== 'string') {
throw new Error('Invalid method config name: invalid service');
}
const result = {
service: obj.service,
};
if ('method' in obj) {
if (typeof obj.method === 'string') {
result.method = obj.method;
}
else {
throw new Error('Invalid method config name: invalid method');
}
}
return result;
}
function validateMethodConfig(obj) {
const result = {
name: [],
};
if (!('name' in obj) || !Array.isArray(obj.name)) {
throw new Error('Invalid method config: invalid name array');
}
for (const name of obj.name) {
result.name.push(validateName(name));
}
if ('waitForReady' in obj) {
if (typeof obj.waitForReady !== 'boolean') {
throw new Error('Invalid method config: invalid waitForReady');
}
result.waitForReady = obj.waitForReady;
}
if ('timeout' in obj) {
if (!(typeof obj.timeout === 'string') ||
!TIMEOUT_REGEX.test(obj.timeout)) {
throw new Error('Invalid method config: invalid timeout');
}
result.timeout = obj.timeout;
}
if ('maxRequestBytes' in obj) {
if (typeof obj.maxRequestBytes !== 'number') {
throw new Error('Invalid method config: invalid maxRequestBytes');
}
result.maxRequestBytes = obj.maxRequestBytes;
}
if ('maxResponseBytes' in obj) {
if (typeof obj.maxResponseBytes !== 'number') {
throw new Error('Invalid method config: invalid maxRequestBytes');
}
result.maxResponseBytes = obj.maxResponseBytes;
}
return result;
}
function validateServiceConfig(obj) {
const result = {
loadBalancingConfig: [],
methodConfig: [],
};
if ('loadBalancingPolicy' in obj) {
if (typeof obj.loadBalancingPolicy === 'string') {
result.loadBalancingPolicy = obj.loadBalancingPolicy;
}
else {
throw new Error('Invalid service config: invalid loadBalancingPolicy');
}
}
if ('loadBalancingConfig' in obj) {
if (Array.isArray(obj.loadBalancingConfig)) {
for (const config of obj.loadBalancingConfig) {
result.loadBalancingConfig.push(load_balancer_1.validateLoadBalancingConfig(config));
}
}
else {
throw new Error('Invalid service config: invalid loadBalancingConfig');
}
}
if ('methodConfig' in obj) {
if (Array.isArray(obj.methodConfig)) {
for (const methodConfig of obj.methodConfig) {
result.methodConfig.push(validateMethodConfig(methodConfig));
}
}
}
// Validate method name uniqueness
const seenMethodNames = [];
for (const methodConfig of result.methodConfig) {
for (const name of methodConfig.name) {
for (const seenName of seenMethodNames) {
if (name.service === seenName.service &&
name.method === seenName.method) {
throw new Error(`Invalid service config: duplicate name ${name.service}/${name.method}`);
}
}
seenMethodNames.push(name);
}
}
return result;
}
exports.validateServiceConfig = validateServiceConfig;
function validateCanaryConfig(obj) {
if (!('serviceConfig' in obj)) {
throw new Error('Invalid service config choice: missing service config');
}
const result = {
serviceConfig: validateServiceConfig(obj.serviceConfig),
};
if ('clientLanguage' in obj) {
if (Array.isArray(obj.clientLanguage)) {
result.clientLanguage = [];
for (const lang of obj.clientLanguage) {
if (typeof lang === 'string') {
result.clientLanguage.push(lang);
}
else {
throw new Error('Invalid service config choice: invalid clientLanguage');
}
}
}
else {
throw new Error('Invalid service config choice: invalid clientLanguage');
}
}
if ('clientHostname' in obj) {
if (Array.isArray(obj.clientHostname)) {
result.clientHostname = [];
for (const lang of obj.clientHostname) {
if (typeof lang === 'string') {
result.clientHostname.push(lang);
}
else {
throw new Error('Invalid service config choice: invalid clientHostname');
}
}
}
else {
throw new Error('Invalid service config choice: invalid clientHostname');
}
}
if ('percentage' in obj) {
if (typeof obj.percentage === 'number' &&
0 <= obj.percentage &&
obj.percentage <= 100) {
result.percentage = obj.percentage;
}
else {
throw new Error('Invalid service config choice: invalid percentage');
}
}
// Validate that no unexpected fields are present
const allowedFields = [
'clientLanguage',
'percentage',
'clientHostname',
'serviceConfig',
];
for (const field in obj) {
if (!allowedFields.includes(field)) {
throw new Error(`Invalid service config choice: unexpected field ${field}`);
}
}
return result;
}
function validateAndSelectCanaryConfig(obj, percentage) {
if (!Array.isArray(obj)) {
throw new Error('Invalid service config list');
}
for (const config of obj) {
const validatedConfig = validateCanaryConfig(config);
/* For each field, we check if it is present, then only discard the
* config if the field value does not match the current client */
if (typeof validatedConfig.percentage === 'number' &&
percentage > validatedConfig.percentage) {
continue;
}
if (Array.isArray(validatedConfig.clientHostname)) {
let hostnameMatched = false;
for (const hostname of validatedConfig.clientHostname) {
if (hostname === os.hostname()) {
hostnameMatched = true;
}
}
if (!hostnameMatched) {
continue;
}
}
if (Array.isArray(validatedConfig.clientLanguage)) {
let languageMatched = false;
for (const language of validatedConfig.clientLanguage) {
if (language === CLIENT_LANGUAGE_STRING) {
languageMatched = true;
}
}
if (!languageMatched) {
continue;
}
}
return validatedConfig.serviceConfig;
}
throw new Error('No matching service config found');
}
/**
* Find the "grpc_config" record among the TXT records, parse its value as JSON, validate its contents,
* and select a service config with selection fields that all match this client. Most of these steps
* can fail with an error; the caller must handle any errors thrown this way.
* @param txtRecord The TXT record array that is output from a successful call to dns.resolveTxt
* @param percentage A number chosen from the range [0, 100) that is used to select which config to use
* @return The service configuration to use, given the percentage value, or null if the service config
* data has a valid format but none of the options match the current client.
*/
function extractAndSelectServiceConfig(txtRecord, percentage) {
for (const record of txtRecord) {
if (record.length > 0 && record[0].startsWith('grpc_config=')) {
/* Treat the list of strings in this record as a single string and remove
* "grpc_config=" from the beginning. The rest should be a JSON string */
const recordString = record.join('').substring('grpc_config='.length);
const recordJson = JSON.parse(recordString);
return validateAndSelectCanaryConfig(recordJson, percentage);
}
}
return null;
}
exports.extractAndSelectServiceConfig = extractAndSelectServiceConfig;
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