Added lambda adapter

.changeset/twelve-apes-try.md

@@ -0,0 +1,5 @@
+---
+"grafserv": patch
+---
+
+Added AWS lambda adapter for grafserv

grafast/grafserv/examples/example-lambda.mjs

@@ -0,0 +1,11 @@
+import { grafserv } from "grafserv/lambda/v1";
+
+import preset from "./graphile.config.mjs";
+import schema from "./schema.mjs";
+
+// Create a Grafserv instance
+const serv = grafserv({ schema, preset });
+
+// Let lambda call into its handler
+export const handler = serv.createHandler()
+

grafast/grafserv/package.json

@@ -96,6 +96,7 @@
     }
   },
   "devDependencies": {
+    "@types/aws-lambda": "^8.10.123",
     "@types/express": "^4.17.17",
     "@types/koa": "^2.13.8",
     "@types/koa-bodyparser": "^4.3.10",

grafast/grafserv/src/servers/lambda/v1/index.ts

@@ -0,0 +1,130 @@
+import type {
+  APIGatewayEvent,
+  APIGatewayProxyEvent,
+  APIGatewayProxyResult,
+  Context as LambdaContext,
+} from "aws-lambda";
+
+import { GrafservBase } from "../../../core/base.js";
+import type {
+  GrafservConfig,
+  RequestDigest,
+  Result,
+} from "../../../interfaces.js";
+import { processHeaders } from "../../../utils.js";
+
+declare global {
+  // eslint-disable-next-line @typescript-eslint/no-namespace
+  namespace Grafast {
+    interface RequestContext {
+      lambdav1: { event: APIGatewayProxyEvent; context: LambdaContext };
+    }
+  }
+}
+
+/** @experimental */
+export class LambdaGrafserv extends GrafservBase {
+  protected lambdaRequestToGrafserv(
+    event: APIGatewayEvent,
+    context: LambdaContext,
+  ): RequestDigest {
+    const version = event.requestContext.protocol.match(
+      /^HTTP\/(?<major>[0-9]+)\.(?<minor>[0-9]+)$/,
+    );
+
+    return {
+      httpVersionMajor: parseInt(version?.groups?.major ?? "1"),
+      httpVersionMinor: parseInt(version?.groups?.minor ?? "0"),
+      isSecure: false, // Because we don't trust X-Forwarded-Proto
+      method: event.httpMethod,
+      path: event.requestContext.path,
+      headers: processHeaders(event.multiValueHeaders),
+      getQueryParams() {
+        return Object.fromEntries(
+          Object.entries(event.queryStringParameters ?? {}).filter(
+            ([_k, v]) => v !== undefined,
+          ),
+        ) as Record<string, string>;
+      },
+      getBody() {
+        return {
+          type: "text",
+          text: event.body ?? "",
+        };
+      },
+      requestContext: {
+        lambdav1: { event, context },
+      },
+      preferJSON: true,
+    };
+  }
+
+  protected grafservResponseToLambda(response: Result | null) {
+    if (response === null) {
+      return {
+        statusCode: 404,
+        body: "¯\\_(ツ)_/¯",
+      };
+    }
+
+    switch (response.type) {
+      case "error": {
+        const { statusCode, headers, error } = response;
+        return {
+          statusCode,
+          headers: { ...headers, "Content-Type": "text/plain" },
+          body: error.message,
+        };
+      }
+
+      case "buffer": {
+        const { statusCode, headers, buffer } = response;
+        return { statusCode, headers, body: buffer.toString("utf8") };
+      }
+
+      case "json": {
+        const { statusCode, headers, json } = response;
+        return { statusCode, headers, body: JSON.stringify(json) };
+      }
+
+      default: {
+        console.log("Unhandled:");
+        console.dir(response);
+        return {
+          statusCode: 501,
+          headers: { "Content-Type": "text/plain" },
+          body: "Server hasn't implemented this yet",
+        };
+      }
+    }
+  }
+
+  createHandler() {
+    // eslint-disable-next-line @typescript-eslint/no-this-alias
+    return async (
+      event: APIGatewayEvent,
+      context: LambdaContext,
+    ): Promise<APIGatewayProxyResult> => {
+      return this.grafservResponseToLambda(
+        await this.processLambdaRequest(
+          event,
+          context,
+          this.lambdaRequestToGrafserv(event, context),
+        ),
+      );
+    };
+  }
+
+  protected processLambdaRequest(
+    _event: APIGatewayEvent,
+    _context: LambdaContext,
+    request: RequestDigest,
+  ) {
+    return this.processRequest(request);
+  }
+}
+
+/** @experimental */
+export function grafserv(config: GrafservConfig) {
+  return new LambdaGrafserv(config);
+}

grafast/grafserv/src/utils.ts

@@ -292,3 +292,13 @@ export function parseGraphQLJSONBody(
     extensions,
   };
 }
+
+export async function concatBufferIterator(
+  bufferIterator: AsyncGenerator<Buffer>,
+) {
+  const buffers = [];
+  for await (const buffer of bufferIterator) {
+    buffers.push(buffer);
+  }
+  return Buffer.concat(buffers);
+}

grafast/website/grafserv/servers/lambda.md

@@ -1,15 +1,26 @@
 # Lambda
 
-**TODO: actually implement this!**
+**THIS INTEGRATION IS EXPERIMENTAL**. PRs improving it are welcome.
+
+Grafserv supports the following AWS lambda configurations:
+
+## AWS API Gateway v2
+
+To deploy Grafserv in API Gateway v2:
+
+- Create an Node 18.x lambda following the instructions at https://docs.aws.amazon.com/lambda/latest/dg/lambda-nodejs.html
+- Add `grafserv` as a dependency using your node package manager of choice
+- Replace your lambda's handler implementation with the code below
+- Deploy your lambda as a zip package following the instructions at https://docs.aws.amazon.com/lambda/latest/dg/nodejs-package.html#nodejs-package-create-dependencies
 
 ```js
-import { grafserv } from "grafserv/lambda";
+import { grafserv } from "grafserv/lambda/v1";
 import preset from "./graphile.config.mjs";
 import schema from "./schema.mjs";
 
 // Create a Grafserv instance
 const serv = grafserv({ schema, preset });
 
 // Export a lambda handler for GraphQL
-export const handler = serv.createGraphQLHandler();
+export const handler = serv.createHandler();
 ```

yarn.lock

@@ -5105,6 +5105,13 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@types/aws-lambda@npm:^8.10.123":
+  version: 8.10.123
+  resolution: "@types/aws-lambda@npm:8.10.123"
+  checksum: 3336788a2b0fbdca0ce1b643ab5c35219e939ef0e0fa474029efe7cd618e5e8c3dc68180bd8ac3eaeb73b234d4cd01c2a30b7601e6eb0ecfc863b5142966c0b0
+  languageName: node
+  linkType: hard
+
 "@types/babel__core@npm:^7.1.14":
   version: 7.20.1
   resolution: "@types/babel__core@npm:7.20.1"
@@ -11789,6 +11796,7 @@ __metadata:
   resolution: "grafserv@workspace:grafast/grafserv"
   dependencies:
     "@graphile/lru": "workspace:^"
+    "@types/aws-lambda": "npm:^8.10.123"
     "@types/express": "npm:^4.17.17"
     "@types/koa": "npm:^2.13.8"
     "@types/koa-bodyparser": "npm:^4.3.10"