invoke the lambda directly without using the API gateway

Author: Vlasis-Perdikidis

infrastructure/terraform/components/api/module_lambda_supplier_mock.tf

@@ -35,7 +35,8 @@ module "supplier_mock" {
   log_subscription_role_arn = local.acct.log_subscription_role_arn
 
   lambda_env_vars = merge(local.common_lambda_env_vars, {
-    ENVIRONMENT = var.environment
+    ENVIRONMENT               = var.environment
+    GET_LETTERS_FUNCTION_NAME = module.get_letters.function_name
   })
 }
 

lambdas/supplier-mock/src/deps.ts

@@ -1,57 +1,21 @@
-/* eslint-disable sonarjs/no-commented-code */
 import { Logger } from "pino";
 import { createLogger } from "@internal/helpers/src";
 import { LambdaClient } from "@aws-sdk/client-lambda";
-import {
-  APIGatewayClient,
-  paginateGetRestApis,
-} from "@aws-sdk/client-api-gateway";
 import { EnvVars, envVars } from "./env";
 
 export type Deps = {
   logger: Logger;
   env: EnvVars;
   lambdaClient: LambdaClient;
-  apiClient: APIGatewayClient;
-  baseUrl: string;
 };
 
-export async function createDependenciesContainer(): Promise<Deps> {
+export function createDependenciesContainer(): Deps {
   const log = createLogger({ logLevel: envVars.PINO_LOG_LEVEL });
   const lambdaClient = new LambdaClient();
-  const apiClient = new APIGatewayClient();
-  const baseUrl = await getRestApiGatewayBaseUrl(envVars, apiClient, log);
 
   return {
     logger: log,
     env: envVars,
     lambdaClient,
-    apiClient,
-    baseUrl,
   };
 }
-
-async function getRestApiGatewayBaseUrl(
-  environment: EnvVars,
-  apiClient: APIGatewayClient,
-  logger: Logger,
-): Promise<string> {
-  logger.info(
-    "VLASIS - about to retrieve API Gateway base URL using API client",
-  );
-  // const apiName = `nhs-${environment.ENVIRONMENT}-supapi`;
-  const apiName = `nhs-pr535-supapi`;
-  const api = await getApi(apiName, apiClient);
-  // return `https://${api.id}.execute-api.${environment.AWS_REGION}.amazonaws.com/main`;
-  return `https://${api.id}.execute-api.eu-west-2.amazonaws.com/main`;
-}
-
-async function getApi(apiName: string, client: APIGatewayClient) {
-  for await (const page of paginateGetRestApis({ client }, {})) {
-    const filtered = page.items?.filter((api) => api.name === apiName);
-    if (filtered?.length === 1) {
-      return filtered[0];
-    }
-  }
-  throw new Error(`API with name "${apiName}" not found.`);
-}

lambdas/supplier-mock/src/env.ts

@@ -4,6 +4,7 @@ const EnvVarsSchema = z.object({
   PINO_LOG_LEVEL: z.coerce.string().optional(),
   ENVIRONMENT: z.string().optional(),
   AWS_REGION: z.string().optional(),
+  GET_LETTERS_FUNCTION_NAME: z.string().optional(),
 });
 
 export type EnvVars = z.infer<typeof EnvVarsSchema>;

lambdas/supplier-mock/src/index.ts

@@ -4,8 +4,4 @@ import createHandler from "./supplier-mock";
 const containerPromise = createDependenciesContainer();
 
 // eslint-disable-next-line import-x/prefer-default-export
-export const supplierMockHandler = async (
-  ...args: Parameters<ReturnType<typeof createHandler>>
-) => {
-  return createHandler(await containerPromise)(...args);
-};
+export const supplierMockHandler = createHandler(containerPromise);

lambdas/supplier-mock/src/supplier-mock.ts

@@ -1,4 +1,5 @@
 /* eslint-disable sonarjs/no-commented-code */
+import { InvokeCommand } from "@aws-sdk/client-lambda";
 import { Deps } from "./deps";
 import { RequestHeaders } from "../../../tests/constants/request-headers";
 
@@ -35,22 +36,46 @@ export default function createHandler(deps: Deps) {
     //   }),
     // );
 
-    deps.logger.info(
-      "VLASIS - about to make a request to the get letters endpoint of the supplier API",
-    );
-    deps.logger.info(`Base URL from deps: ${deps.baseUrl}`);
+    deps.logger.info("Invoking get_letters lambda directly");
+
+    if (!deps.env.GET_LETTERS_FUNCTION_NAME) {
+      throw new Error("GET_LETTERS_FUNCTION_NAME is not configured");
+    }
+
     const headers: RequestHeaders = {
       "NHSD-Supplier-ID": "TestSupplier1",
       "NHSD-Correlation-ID": "12345",
       "X-Request-ID": "requestId1",
     };
 
-    const getLettersResponse = await fetch(`${deps.baseUrl}/letters`, {
-      method: "GET",
-      headers,
-    });
+    const invokeResponse = await deps.lambdaClient.send(
+      new InvokeCommand({
+        FunctionName: deps.env.GET_LETTERS_FUNCTION_NAME,
+        InvocationType: "RequestResponse",
+        Payload: Buffer.from(
+          JSON.stringify({
+            headers: {
+              "nhsd-supplier-id": headers["NHSD-Supplier-ID"],
+              "nhsd-correlation-id": headers["NHSD-Correlation-ID"],
+              "x-request-id": headers["X-Request-ID"],
+            },
+            queryStringParameters: null,
+            requestContext: {},
+          }),
+        ),
+      }),
+    );
+
+    const responsePayload = invokeResponse.Payload
+      ? JSON.parse(Buffer.from(invokeResponse.Payload).toString("utf8"))
+      : undefined;
+
     deps.logger.info(
-      `Response from get letters lambda: ${getLettersResponse.status} - ${getLettersResponse.statusText}`,
+      {
+        statusCode: responsePayload?.statusCode,
+        functionError: invokeResponse.FunctionError,
+      },
+      "Received response from get_letters lambda",
     );
   };
 }