Update request

Squashed commit of the following:

commit 5afeab357b73494d690c33952efd41b29367fab5
Author: rijkvanzanten <rijkvanzanten@me.com>
Date:   Fri Feb 24 15:39:15 2023 -0500

    Add dns pre-resolve

commit 68e0e8c8099b5463297185f220e80b2b6d5b980a
Author: rijkvanzanten <rijkvanzanten@me.com>
Date:   Fri Feb 24 12:28:18 2023 -0500

    Start on request interceptor

api/src/request/index.ts

@@ -1,4 +1,5 @@
 import type { AxiosInstance } from 'axios';
+import { requestInterceptor } from './request-interceptor';
 import { responseInterceptor } from './response-interceptor';
 
 export const _cache: { axiosInstance: AxiosInstance | null } = {
@@ -9,6 +10,7 @@ export async function getAxios() {
 	if (!_cache.axiosInstance) {
 		const axios = (await import('axios')).default;
 		_cache.axiosInstance = axios.create();
+		_cache.axiosInstance.interceptors.request.use(requestInterceptor);
 		_cache.axiosInstance.interceptors.response.use(responseInterceptor);
 	}
 

api/src/request/request-interceptor.test.ts

@@ -0,0 +1,104 @@
+import { randIp, randUrl, randWord } from '@ngneat/falso';
+import type { InternalAxiosRequestConfig } from 'axios';
+import axios from 'axios';
+import type { LookupAddress } from 'node:dns';
+import { lookup } from 'node:dns/promises';
+import { isIP } from 'node:net';
+import { URL } from 'node:url';
+import { afterEach, beforeEach, expect, test, vi } from 'vitest';
+import logger from '../logger';
+import { requestInterceptor } from './request-interceptor';
+import { validateIP } from './validate-ip';
+
+vi.mock('axios');
+vi.mock('node:net');
+vi.mock('node:url');
+vi.mock('node:dns/promises');
+vi.mock('./validate-ip');
+vi.mock('../logger');
+
+let sample: {
+	config: InternalAxiosRequestConfig;
+	url: string;
+	hostname: string;
+	ip: string;
+};
+
+beforeEach(() => {
+	sample = {
+		config: {} as InternalAxiosRequestConfig,
+		url: randUrl(),
+		hostname: randWord(),
+		ip: randIp(),
+	};
+
+	vi.mocked(axios.getUri).mockReturnValue(sample.url);
+	vi.mocked(URL).mockReturnValue({ hostname: sample.hostname } as URL);
+	vi.mocked(lookup).mockResolvedValue({ address: sample.ip } as LookupAddress);
+	vi.mocked(isIP).mockReturnValue(0);
+});
+
+afterEach(() => {
+	vi.resetAllMocks();
+});
+
+test('Uses axios getUri to get full URI', async () => {
+	await requestInterceptor(sample.config);
+	expect(axios.getUri).toHaveBeenCalledWith(sample.config);
+});
+
+test('Gets hostname using URL', async () => {
+	await requestInterceptor(sample.config);
+	expect(URL).toHaveBeenCalledWith(sample.url);
+});
+
+test('Checks if hostname is IP', async () => {
+	await requestInterceptor(sample.config);
+	expect(isIP).toHaveBeenCalledWith(sample.hostname);
+});
+
+test('Looks up IP address using dns lookup if hostname is not an IP address', async () => {
+	await requestInterceptor(sample.config);
+	expect(lookup).toHaveBeenCalledWith(sample.hostname);
+});
+
+test('Logs when the lookup throws an error', async () => {
+	const mockError = new Error();
+	vi.mocked(lookup).mockRejectedValue(mockError);
+
+	try {
+		await requestInterceptor(sample.config);
+	} catch {
+		// Expect to error
+	} finally {
+		expect(logger.warn).toHaveBeenCalledWith(mockError, `Couldn't lookup the DNS for url "${sample.url}"`);
+	}
+});
+
+test('Throws error when dns lookup fails', async () => {
+	const mockError = new Error();
+	vi.mocked(lookup).mockRejectedValue(mockError);
+
+	try {
+		await requestInterceptor(sample.config);
+	} catch (err: any) {
+		expect(err).toBeInstanceOf(Error);
+		expect(err.message).toBe(`Requested URL "${sample.url}" resolves to a denied IP address`);
+	}
+});
+
+test('Validates IP', async () => {
+	await requestInterceptor(sample.config);
+	expect(validateIP).toHaveBeenCalledWith(sample.ip, sample.url);
+});
+
+test('Validates IP from hostname if URL hostname is IP', async () => {
+	vi.mocked(isIP).mockReturnValue(4);
+	await requestInterceptor(sample.config);
+	expect(validateIP).toHaveBeenCalledWith(sample.hostname, sample.url);
+});
+
+test('Returns config unmodified', async () => {
+	const config = await requestInterceptor(sample.config);
+	expect(config).toBe(config);
+});

api/src/request/request-interceptor.ts

@@ -0,0 +1,31 @@
+import type { InternalAxiosRequestConfig } from 'axios';
+import axios from 'axios';
+import { lookup } from 'node:dns/promises';
+import { isIP } from 'node:net';
+import { URL } from 'node:url';
+import logger from '../logger';
+import { validateIP } from './validate-ip';
+
+export const requestInterceptor = async (config: InternalAxiosRequestConfig) => {
+	const uri = axios.getUri(config);
+
+	const { hostname } = new URL(uri);
+
+	let ip;
+
+	if (isIP(hostname) === 0) {
+		try {
+			const dns = await lookup(hostname);
+			ip = dns.address;
+		} catch (err: any) {
+			logger.warn(err, `Couldn't lookup the DNS for url "${uri}"`);
+			throw new Error(`Requested URL "${uri}" resolves to a denied IP address`);
+		}
+	} else {
+		ip = hostname;
+	}
+
+	await validateIP(ip, uri);
+
+	return config;
+};