src: implement OriginProvider and S2Provider

Implements the `OriginProvider` and `S3Provider` classes as described in #111. Allows `R2Provider` to take in a fallback provider that will be used if R2 fails.

src/env.ts

@@ -50,4 +50,6 @@ export interface Env {
    * Host for the www/Digital Ocean/origin server
    */
   FALLBACK_HOST: string;
+
+  ORIGIN_HOST: string;
 }

src/providers/originProvider.ts

@@ -0,0 +1,105 @@
+import { CACHE_HEADERS } from '../constants/cache';
+import { Context } from '../context';
+import {
+  GetFileOptions,
+  GetFileResult,
+  HeadFileResult,
+  HttpResponseHeaders,
+  Provider,
+  ReadDirectoryResult,
+} from './provider';
+
+type OriginProviderCtorOptions = {
+  ctx: Context;
+};
+
+/**
+ * Serves assets from origin.nodejs.org, used as a fallback for if R2 fails.
+ */
+export class OriginProvider implements Provider {
+  private ctx: Context;
+
+  constructor({ ctx }: OriginProviderCtorOptions) {
+    this.ctx = ctx;
+  }
+
+  async headFile(path: string): Promise<HeadFileResult | undefined> {
+    const res = await fetch(this.ctx.env.ORIGIN_HOST + path, {
+      method: 'HEAD',
+      headers: {
+        'user-agent': 'release-cloudflare-worker',
+      },
+    });
+
+    if (res.status === 404) {
+      return undefined;
+    }
+
+    return {
+      httpStatusCode: res.status,
+      httpHeaders: originHeadersToOurHeadersObject(res.headers),
+    };
+  }
+
+  async getFile(
+    path: string,
+    options?: GetFileOptions | undefined
+  ): Promise<GetFileResult | undefined> {
+    const res = await fetch(this.ctx.env.ORIGIN_HOST + path, {
+      headers: {
+        'user-agent': 'release-cloudflare-worker',
+        'if-match': options?.conditionalHeaders?.ifMatch ?? '',
+        'if-none-match': options?.conditionalHeaders?.ifMatch ?? '',
+        'if-modified-since':
+          options?.conditionalHeaders?.ifModifiedSince?.toUTCString() ?? '',
+        'if-unmodified-since':
+          options?.conditionalHeaders?.ifUnmodifiedSince?.toUTCString() ?? '',
+        range: options?.rangeHeader ?? '',
+      },
+    });
+
+    if (res.status === 404) {
+      return undefined;
+    }
+
+    return {
+      contents: res.body,
+      httpStatusCode: res.status,
+      httpHeaders: originHeadersToOurHeadersObject(res.headers),
+    };
+  }
+
+  async readDirectory(path: string): Promise<ReadDirectoryResult | undefined> {
+    const res = await fetch(this.ctx.env.ORIGIN_HOST + path, {
+      headers: {
+        'user-agent': 'release-cloudflare-worker',
+      },
+    });
+
+    if (res.status === 404) {
+      return undefined;
+    }
+
+    return {
+      body: res.body,
+      httpStatusCode: res.status,
+      httpHeaders: originHeadersToOurHeadersObject(res.headers),
+    };
+  }
+}
+
+function originHeadersToOurHeadersObject(
+  headers: Headers
+): HttpResponseHeaders {
+  return {
+    etag: headers.get('etag') ?? '',
+    'accept-range': headers.get('accept-range') ?? 'bytes',
+    'access-control-allow-origin':
+      headers.get('access-control-allow-origin') ?? '',
+    'cache-control': CACHE_HEADERS.failure, // We don't want to cache these responses
+    'last-modified': headers.get('last-modified') ?? '',
+    'content-language': headers.get('content-language') ?? '',
+    'content-disposition': headers.get('content-disposition') ?? '',
+    'content-length': headers.get('content-length') ?? '0',
+  };
+}

src/providers/provider.ts

@@ -32,6 +32,10 @@ export type HttpResponseHeaders = {
 };
 
 export type HeadFileResult = {
+  /**
+   * Status code to send the client
+   */
+  httpStatusCode: number;
   /**
    * Headers to send the client
    */
@@ -72,6 +76,7 @@ export type File = {
 
 export type R2ReadDirectoryResult = {
   subdirectories: string[];
+  hasIndexHtmlFile: boolean;
   files: File[];
 };
 

src/providers/r2Provider.ts

@@ -12,9 +12,11 @@ import {
   Provider,
   ReadDirectoryResult,
 } from './provider';
+import { S3Provider } from './s3Provider';
 
 type R2ProviderCtorOptions = {
   ctx: Context;
+  fallbackProvider?: Provider;
 };
 
 export class R2Provider implements Provider {
@@ -41,6 +43,7 @@ export class R2Provider implements Provider {
     }
 
     return {
+      httpStatusCode: 200,
       httpHeaders: r2MetadataToHeaders(object, 200),
     };
   }
@@ -83,9 +86,12 @@ export class R2Provider implements Provider {
     };
   }
 
-  readDirectory(_: string): Promise<ReadDirectoryResult | undefined> {
-    // We will use the S3Provider here
-    throw new Error('Method not implemented.');
+  readDirectory(path: string): Promise<ReadDirectoryResult | undefined> {
+    const s3Provider = new S3Provider({
+      ctx: this.ctx,
+      fallbackProvider: this.fallbackProvider,
+    });
+    return s3Provider.readDirectory(path);
   }
 }
 

src/providers/s3Provider.ts

@@ -0,0 +1,107 @@
+import { ListObjectsV2Command, S3Client } from '@aws-sdk/client-s3';
+import { Context } from '../context';
+import {
+  File,
+  GetFileOptions,
+  GetFileResult,
+  HeadFileResult,
+  Provider,
+  ReadDirectoryResult,
+} from './provider';
+import { retryWrapper } from '../utils/provider';
+import { R2_RETRY_LIMIT, S3_MAX_KEYS } from '../constants/limits';
+
+type S3ProviderCtorOptions = {
+  ctx: Context;
+};
+
+/**
+ * This provides assets from an S3-compatible data source. In our case, it's
+ *  still R2. We use this only for directory listing. In R2's bindings api,
+ *  there's some internal response size limit that makes us need to send
+ *  an absurd amount of requests in order to list the full contents of some
+ *  directories. Using the S3 api was the recommended fix from the R2 team.
+ */
+export class S3Provider implements Provider {
+  private ctx: Context;
+  private client: S3Client;
+
+  constructor({ ctx }: S3ProviderCtorOptions) {
+    this.ctx = ctx;
+
+    this.client = new S3Client({
+      region: 'auto',
+      endpoint: ctx.env.S3_ENDPOINT,
+      credentials: {
+        accessKeyId: ctx.env.S3_ACCESS_KEY_ID,
+        secretAccessKey: ctx.env.S3_ACCESS_KEY_SECRET,
+      },
+    });
+  }
+
+  headFile(_: string): Promise<HeadFileResult | undefined> {
+    throw new Error('Method not implemented.');
+  }
+
+  getFile(
+    _: string,
+    _2?: GetFileOptions | undefined
+  ): Promise<GetFileResult | undefined> {
+    throw new Error('Method not implemented.');
+  }
+
+  async readDirectory(path: string): Promise<ReadDirectoryResult | undefined> {
+    const directories = new Set<string>();
+    let hasIndexHtmlFile = false;
+    const files: File[] = [];
+
+    let isTruncated = true;
+    let cursor: string | undefined;
+    while (isTruncated) {
+      const result = await retryWrapper(
+        async () => {
+          return this.client.send(
+            new ListObjectsV2Command({
+              Bucket: this.ctx.env.BUCKET_NAME,
+              Prefix: path,
+              Delimiter: '/',
+              MaxKeys: S3_MAX_KEYS,
+              ContinuationToken: cursor,
+            })
+          );
+        },
+        R2_RETRY_LIMIT,
+        this.ctx.sentry
+      );
+
+      result.CommonPrefixes?.forEach(directory => {
+        directories.add(directory.Prefix!.substring(path.length));
+      });
+
+      result.Contents?.forEach(object => {
+        if (object.Key!.endsWith('index.html')) {
+          hasIndexHtmlFile = true;
+        }
+
+        files.push({
+          name: object.Key!.substring(path.length),
+          size: object.Size!,
+          lastModified: object.LastModified!,
+        });
+      });
+
+      isTruncated = result.IsTruncated ?? false;
+      cursor = result.NextContinuationToken;
+    }
+
+    if (directories.size === 0 && files.length === 0) {
+      return undefined;
+    }
+
+    return {
+      subdirectories: Array.from(directories),
+      hasIndexHtmlFile,
+      files,
+    };
+  }
+}

wrangler.toml

@@ -15,6 +15,7 @@ DIRECTORY_CACHE_CONTROL = 'public, max-age=3600, s-maxage=14400'
 BUCKET_NAME = 'dist-prod'
 USE_FALLBACK_WHEN_R2_FAILS = false
 FALLBACK_HOST = 'https://origin.nodejs.org'
+ORIGIN_HOST = 'https://origin.nodejs.org'
 
 [[r2_buckets]]
 binding = 'R2_BUCKET'
@@ -33,6 +34,7 @@ DIRECTORY_CACHE_CONTROL = 'public, max-age=3600, s-maxage=14400'
 BUCKET_NAME = 'dist-prod'
 USE_FALLBACK_WHEN_R2_FAILS = true
 FALLBACK_HOST = 'https://origin.nodejs.org'
+ORIGIN_HOST = 'https://origin.nodejs.org'
 
 [[env.staging.r2_buckets]]
 binding = 'R2_BUCKET'
@@ -51,6 +53,7 @@ DIRECTORY_CACHE_CONTROL = 'public, max-age=3600, s-maxage=14400'
 BUCKET_NAME='dist-prod'
 USE_FALLBACK_WHEN_R2_FAILS = true
 FALLBACK_HOST = 'https://origin.nodejs.org'
+ORIGIN_HOST = 'https://origin.nodejs.org'
 
 [[env.prod.r2_buckets]]
 binding = 'R2_BUCKET'