Add support for S3 express endpoints (#629)

* Store credential in middleware context

* Add support for S3 express endpoints

* Update testMiddleware

* Add S3Middleware executionContext task local

* throw error if URL init fails

* Make AWSClient.logger public

Author: adam-fowler

Sources/SotoCore/AWSClient.swift

@@ -48,7 +48,7 @@ public final class AWSClient: Sendable {
     /// HTTP client used by AWSClient
     public let httpClient: AWSHTTPClient
     /// Logger used for non-request based output
-    let clientLogger: Logger
+    public let logger: Logger
     /// client options
     let options: Options
 
@@ -71,13 +71,13 @@ public final class AWSClient: Sendable {
         middleware: some AWSMiddlewareProtocol,
         options: Options = Options(),
         httpClient: AWSHTTPClient = HTTPClient.shared,
-        logger clientLogger: Logger = AWSClient.loggingDisabled
+        logger: Logger = AWSClient.loggingDisabled
     ) {
         self.httpClient = httpClient
         let credentialProvider = credentialProviderFactory.createProvider(
             context: .init(
                 httpClient: self.httpClient,
-                logger: clientLogger,
+                logger: logger,
                 options: options
             )
         )
@@ -88,7 +88,7 @@ public final class AWSClient: Sendable {
             RetryMiddleware(retryPolicy: retryPolicyFactory.retryPolicy)
             ErrorHandlingMiddleware(options: options)
         }
-        self.clientLogger = clientLogger
+        self.logger = logger
         self.options = options
     }
 
@@ -105,13 +105,13 @@ public final class AWSClient: Sendable {
         retryPolicy retryPolicyFactory: RetryPolicyFactory = .default,
         options: Options = Options(),
         httpClient: AWSHTTPClient = HTTPClient.shared,
-        logger clientLogger: Logger = AWSClient.loggingDisabled
+        logger: Logger = AWSClient.loggingDisabled
     ) {
         self.httpClient = httpClient
         let credentialProvider = credentialProviderFactory.createProvider(
             context: .init(
                 httpClient: self.httpClient,
-                logger: clientLogger,
+                logger: logger,
                 options: options
             )
         )
@@ -121,7 +121,7 @@ public final class AWSClient: Sendable {
             RetryMiddleware(retryPolicy: retryPolicyFactory.retryPolicy)
             ErrorHandlingMiddleware(options: options)
         }
-        self.clientLogger = clientLogger
+        self.logger = logger
         self.options = options
     }
 
@@ -402,9 +402,15 @@ extension AWSClient {
             try Task.checkCancellation()
             // combine service and client middleware stacks
             let middlewareStack = config.middleware.map { AWSDynamicMiddlewareStack($0, self.middleware) } ?? self.middleware
+            let credential = try await self.credentialProvider.getCredential(logger: logger)
             let middlewareContext = AWSMiddlewareContext(
                 operation: operationName,
                 serviceConfig: config,
+                credential: StaticCredential(
+                    accessKeyId: credential.accessKeyId,
+                    secretAccessKey: credential.secretAccessKey,
+                    sessionToken: credential.sessionToken
+                ),
                 logger: logger
             )
             // run middleware stack with httpClient execute at the end

Sources/SotoCore/Credential/Credential+IsEmpty.swift

@@ -18,4 +18,8 @@ extension Credential {
     func isEmpty() -> Bool {
         self.accessKeyId.isEmpty || self.secretAccessKey.isEmpty
     }
+
+    func getStaticCredential() -> StaticCredential {
+        .init(accessKeyId: accessKeyId, secretAccessKey: secretAccessKey, sessionToken: sessionToken)
+    }
 }

Sources/SotoCore/Credential/CredentialProvider.swift

@@ -170,7 +170,7 @@ extension CredentialProviderFactory {
     /// Don't supply any credentials
     public static var empty: CredentialProviderFactory {
         Self { _ in
-            StaticCredential(accessKeyId: "", secretAccessKey: "")
+            EmptyCredential()
         }
     }
 

Sources/SotoCore/Credential/EmptyCredential.swift

@@ -0,0 +1,24 @@
+//===----------------------------------------------------------------------===//
+//
+// This source file is part of the Soto for AWS open source project
+//
+// Copyright (c) 2017-2023 the Soto project authors
+// Licensed under Apache License v2.0
+//
+// See LICENSE.txt for license information
+// See CONTRIBUTORS.txt for the list of Soto project authors
+//
+// SPDX-License-Identifier: Apache-2.0
+//
+//===----------------------------------------------------------------------===//
+
+/// Empty credentials
+public struct EmptyCredential: CredentialProvider, Credential {
+    public var accessKeyId: String { "" }
+    public var secretAccessKey: String { "" }
+    public var sessionToken: String? { nil }
+
+    public func getCredential(logger: Logger) async throws -> any Credential {
+        self
+    }
+}

Sources/SotoCore/HTTP/AWSHTTPBody.swift

@@ -74,6 +74,15 @@ public struct AWSHTTPBody: Sendable {
         }
     }
 
+    public var isEmpty: Bool {
+        switch self.storage {
+        case .byteBuffer(let buffer):
+            return buffer.readableBytes == 0
+        case .asyncSequence(_, let length):
+            return length == 0
+        }
+    }
+
     public var isStreaming: Bool {
         switch self.storage {
         case .byteBuffer:

Sources/SotoCore/Middleware/Middleware.swift

@@ -18,6 +18,7 @@ import Logging
 public struct AWSMiddlewareContext: Sendable {
     public var operation: String
     public var serviceConfig: AWSServiceConfig
+    public var credential: StaticCredential
     public var logger: Logger
 }