fix: add middleware to inject http header

Author: Hweinstock

packages/core/src/shared/awsClientBuilderV3.ts

@@ -113,6 +113,7 @@ export class AWSClientBuilderV3 {
         service.middlewareStack.add(telemetryMiddleware, { step: 'deserialize' })
         service.middlewareStack.add(loggingMiddleware, { step: 'finalizeRequest' })
         service.middlewareStack.add(getEndpointMiddleware(settings), { step: 'build' })
+        service.middlewareStack.add(keepAliveMiddleware, { step: 'build' })
         return service
     }
 }
@@ -155,6 +156,9 @@ function getEndpointMiddleware(settings: DevSettings = DevSettings.instance): Bu
         overwriteEndpoint(next, context, settings, args)
 }
 
+const keepAliveMiddleware: BuildMiddleware<any, any> = (next: BuildHandler<any, any>) => async (args: any) =>
+    addKeepAliveHeader(next, args)
+
 export async function emitOnRequest(next: DeserializeHandler<any, any>, context: HandlerExecutionContext, args: any) {
     if (!HttpResponse.isInstance(args.request)) {
         return next(args)
@@ -176,8 +180,9 @@ export async function emitOnRequest(next: DeserializeHandler<any, any>, context:
 }
 
 export async function logOnRequest(next: FinalizeHandler<any, any>, args: any) {
+    const request = args.request
     if (HttpRequest.isInstance(args.request)) {
-        const { hostname, path } = args.request
+        const { hostname, path } = request
         // TODO: omit credentials / sensitive info from the logs.
         const input = partialClone(args.input, 3)
         getLogger().debug(`API Request (%s %s): %O`, hostname, path, input)
@@ -191,14 +196,23 @@ export function overwriteEndpoint(
     settings: DevSettings,
     args: any
 ) {
-    if (HttpRequest.isInstance(args.request)) {
-        const serviceId = getServiceId(context as object)
+    const request = args.request
+    if (HttpRequest.isInstance(request)) {
+        const serviceId = getServiceId(context satisfies { clientName?: string; commandName?: string })
         const endpoint = serviceId ? settings.get('endpoints', {})[serviceId] : undefined
         if (endpoint) {
             const url = new URL(endpoint)
-            Object.assign(args.request, selectFrom(url, 'hostname', 'port', 'protocol', 'pathname'))
-            args.request.path = args.request.pathname
+            Object.assign(request, selectFrom(url, 'hostname', 'port', 'protocol', 'pathname'))
+            request.path = (request as HttpRequest & { pathname: string }).pathname
         }
     }
     return next(args)
 }
+
+export function addKeepAliveHeader(next: BuildHandler<any, any>, args: any) {
+    const request = args.request
+    if (HttpRequest.isInstance(request)) {
+        request.headers['Connection'] = 'keep-alive'
+    }
+    return next(args)
+}

packages/core/src/testE2E/shared/awsClientBuilderV3.test.ts

@@ -7,27 +7,18 @@ import http from 'http'
 import assert from 'assert'
 import { SSMClient, DescribeSessionsCommand } from '@aws-sdk/client-ssm'
 import { NodeHttpHandler } from '@smithy/node-http-handler'
-import { Logger } from '@aws-sdk/types'
 import { globals } from '../../shared'
 
-describe('SDKv3 Client Behavior', function () {
-    const port = 4576
+describe('AWSClientBuilderV3', function () {
+    const port = 3000
     let server: http.Server
-    let testLogger: Logger
     let requests: http.IncomingMessage[]
 
     before(function () {
         server = http.createServer({ keepAlive: true }, (req, rsp) => {
             rsp.writeHead(200, { 'Content-Type': 'application/json' })
             rsp.end(JSON.stringify({ message: 'success' }))
         })
-        const defaultLog = (m: object) => console.log(JSON.stringify(m, undefined, 3))
-        testLogger = {
-            debug: defaultLog,
-            warn: defaultLog,
-            error: defaultLog,
-            info: defaultLog,
-        }
         server.listen(port, () => {})
         server.on('request', (req) => {
             requests.push(req)
@@ -42,20 +33,20 @@ describe('SDKv3 Client Behavior', function () {
         server.close()
     })
 
-    it('reuses connections', async function () {
+    it('reuses existing HTTP connections', async function () {
         const httpHandler = new NodeHttpHandler({
             httpAgent: new http.Agent({ keepAlive: true }),
         })
         const client = await globals.sdkClientBuilderV3.createAwsService(SSMClient, {
             region: 'us-east-1',
             endpoint: `http://localhost:${port}`,
             requestHandler: httpHandler,
-            logger: testLogger,
         })
         await client.send(new DescribeSessionsCommand({ State: 'Active' }))
         await client.send(new DescribeSessionsCommand({ State: 'Active' }))
 
         assert.strictEqual(requests[0].headers.connection, 'keep-alive')
         assert.strictEqual(requests[1].headers.connection, 'keep-alive')
+        assert.strictEqual(server.connections, 1)
     })
 })