Swift Configuration Integration

.devcontainer/Dockerfile

@@ -1,4 +1,4 @@
-FROM swift:6.2.0
+FROM swift:6.2.3
 
 RUN apt-get update && export DEBIAN_FRONTEND=noninteractive \
      && apt-get -y install --no-install-recommends make git

.github/workflows/swift-test.yml

@@ -18,8 +18,7 @@ jobs:
     strategy:
       matrix:
         image:
-          - swift:6.1.2
-          - swift:6.2.0
+          - swift:6.2.3
     services:
       localstack:
         image: localstack/localstack

Package.swift

@@ -1,4 +1,4 @@
-// swift-tools-version: 6.1
+// swift-tools-version: 6.2
 
 import PackageDescription
 
@@ -31,14 +31,16 @@ let package = Package(
         .package(url: "https://github.com/swift-server/swift-service-lifecycle.git", from: "2.0.0"),
         .package(url: "https://github.com/soto-project/soto.git", from: "7.0.0"),
         .package(url: "https://github.com/apple/swift-log.git", from: "1.6.2"),
-        .package(url: "https://github.com/apple/swift-docc-plugin", from: "1.0.0"),
+        .package(url: "https://github.com/apple/swift-configuration", from: "1.0.0")
     ],
     targets: [
         .executableTarget(
             name: "BreezeLambdaItemAPI",
             dependencies: [
-                "BreezeLambdaAPI"
-            ]
+                "BreezeLambdaAPI",
+                .product(name: "Configuration", package: "swift-configuration")
+            ],
+            resources: [.copy("Resources")]
         ),
         .target(
             name: "BreezeDynamoDBService",
@@ -54,6 +56,7 @@ let package = Package(
                 .product(name: "AWSLambdaRuntime", package: "swift-aws-lambda-runtime"),
                 .product(name: "AWSLambdaEvents", package: "swift-aws-lambda-events"),
                 .product(name: "ServiceLifecycle", package: "swift-service-lifecycle"),
+                .product(name: "Configuration", package: "swift-configuration"),
                 "BreezeDynamoDBService"
             ]
         ),

README.md

@@ -12,7 +12,7 @@
 Add the dependency `BreezeLambdaDynamoDBAPI` to a package:
 
 ```swift
-// swift-tools-version:6.1
+// swift-tools-version:6.2
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription

Sources/BreezeLambdaAPI/BreezeAPIConfiguration.swift

@@ -7,10 +7,10 @@
 
 import SotoDynamoDB
 import BreezeDynamoDBService
-import AWSLambdaRuntime
+import Configuration
 
 /// Defines the configuration for the Breeze Lambda API.
-public protocol APIConfiguring {
+public protocol APIConfiguring: Sendable {
     var dbTimeout: Int64 { get }
     func operation() throws -> BreezeOperation
     func getConfig() throws -> BreezeDynamoDBConfig
@@ -26,11 +26,30 @@ public protocol APIConfiguring {
 /// - `DYNAMO_DB_TABLE_NAME`: The name of the DynamoDB table.
 /// - `DYNAMO_DB_KEY`: The name of the primary key in the DynamoDB table.
 public struct BreezeAPIConfiguration: APIConfiguring {
+    private enum Keys {
+        static let handler: ConfigKey = "_HANDLER"
+        static let awsRegion: ConfigKey = "AWS_REGION"
+        static let tableName: ConfigKey = "DYNAMO_DB_TABLE_NAME"
+        static let keyName: ConfigKey = "DYNAMO_DB_KEY"
+        static let localstackEndpoint: ConfigKey = "LOCALSTACK_ENDPOINT"
+        static let dbTimeout: ConfigKey = "BREEZE_DB_TIMEOUT"
+    }
 
-    public init() {}
+    private let reader: ConfigReader
 
-    /// Timeout for database operations in seconds.
-    public let dbTimeout: Int64 = 30
+    /// Creates the configuration using the supplied providers. Defaults to environment variables.
+    public init(
+        reader: ConfigReader = ConfigReader(
+            providers: [EnvironmentVariablesProvider()]
+        )
+    ) {
+        self.reader = reader
+    }
+
+    /// Timeout for database operations in seconds, configurable via `BREEZE_DB_TIMEOUT`.
+    public var dbTimeout: Int64 {
+        Int64(reader.int(forKey: Keys.dbTimeout, default: 30))
+    }
 
     /// The operation handler for Breeze operations.
     ///
@@ -43,7 +62,7 @@ public struct BreezeAPIConfiguration: APIConfiguring {
     ///
     ///  See BreezeOperation for more details.
     public func operation() throws -> BreezeOperation {
-        guard let handler = Lambda.env("_HANDLER"),
+        guard let handler = reader.string(forKey: Keys.handler),
               let operation = BreezeOperation(handler: handler)
         else {
             throw BreezeLambdaAPIError.invalidHandler
@@ -78,12 +97,10 @@ public struct BreezeAPIConfiguration: APIConfiguring {
     ///
     /// This method is used to determine the AWS region where the DynamoDB table is located.
     func currentRegion() -> Region {
-        if let awsRegion = Lambda.env("AWS_REGION") {
-            let value = Region(rawValue: awsRegion)
-            return value
-        } else {
-            return .useast1
+        if let awsRegion = reader.string(forKey: Keys.awsRegion) {
+            return Region(rawValue: awsRegion)
         }
+        return .useast1
     }
 
     /// Returns the DynamoDB table name from the `DYNAMO_DB_TABLE_NAME` environment variable.
@@ -92,7 +109,7 @@ public struct BreezeAPIConfiguration: APIConfiguring {
     /// This method is used to retrieve the name of the DynamoDB table that will be used by the Breeze Lambda API.
     /// - Important: The table name is essential for performing operations on the DynamoDB table.
     func tableName() throws -> String {
-        guard let tableName = Lambda.env("DYNAMO_DB_TABLE_NAME") else {
+        guard let tableName = reader.string(forKey: Keys.tableName) else {
             throw BreezeLambdaAPIError.tableNameNotFound
         }
         return tableName
@@ -104,7 +121,7 @@ public struct BreezeAPIConfiguration: APIConfiguring {
     /// This method is used to retrieve the name of the primary key in the DynamoDB table that will be used by the Breeze Lambda API.
     /// - Important: The key name is essential for identifying items in the DynamoDB table.
     func keyName() throws -> String {
-        guard let keyName = Lambda.env("DYNAMO_DB_KEY") else {
+        guard let keyName = reader.string(forKey: Keys.keyName) else {
             throw BreezeLambdaAPIError.keyNameNotFound
         }
         return keyName
@@ -120,7 +137,7 @@ public struct BreezeAPIConfiguration: APIConfiguring {
     ///   - To set it you need to set the `LOCALSTACK_ENDPOINT` environment variable to the URL of your LocalStack instance.
     ///   - The Default LocalStack endpoint is `http://localhost:4566`
     func endpoint() -> String? {
-        if let localstack = Lambda.env("LOCALSTACK_ENDPOINT"),
+        if let localstack = reader.string(forKey: Keys.localstackEndpoint),
            !localstack.isEmpty {
             return localstack
         }

Sources/BreezeLambdaAPI/BreezeLambdaAPI.swift

@@ -71,7 +71,7 @@ public actor BreezeLambdaAPI<T: BreezeCodable>: Service {
             let breezeApi = BreezeLambdaHandler<T>(dbManager: dbManager, operation: operation)
             let runtime = LambdaRuntime(body: breezeApi.handle)
             self.serviceGroup = ServiceGroup(
-                services: [runtime, dynamoDBService],
+                services: [dynamoDBService, runtime],
                 gracefulShutdownSignals: [.sigint],
                 cancellationSignals: [.sigterm],
                 logger: logger

Sources/BreezeLambdaAPI/Docs.docc/Docs.md

@@ -45,7 +45,7 @@ public protocol BreezeCodable: Codable, Sendable {
 ### Add the dependency
 
 ```swift
-// swift-tools-version:6.1
+// swift-tools-version:6.2
 // The swift-tools-version declares the minimum version of Swift required to build this package.
 
 import PackageDescription

Sources/BreezeLambdaItemAPI/BreezeLambdaItemAPI.swift

@@ -12,6 +12,7 @@
 //    See the License for the specific language governing permissions and
 //    limitations under the License.
 
+import Configuration
 import BreezeLambdaAPI
 import BreezeDynamoDBService
 
@@ -39,31 +40,20 @@ struct Item: Codable {
 /// BreezeCodable is a protocol that allows the Item struct to be used with Breeze Lambda API.
 extension Item: BreezeCodable { }
 
-/// APIConfiguration is a struct that conforms to APIConfiguring.
-/// It provides the configuration for the Breeze Lambda API, including the DynamoDB table name, key name, and endpoint.
-/// It also specifies the operation to be performed, which in this case is listing items.
-struct APIConfiguration: APIConfiguring {
-    let dbTimeout: Int64 = 30
-    func operation() throws -> BreezeOperation {
-        .list
-    }
-
-    /// Get the configuration for the DynamoDB service.
-    /// It specifies the region, table name, key name, and endpoint.
-    /// In this example, it uses a local Localstack endpoint for testing purposes.
-    /// You can change the region, table name, key name, and endpoint as needed for your application.
-    /// Remove the endpoint for production use.
-    func getConfig() throws -> BreezeDynamoDBConfig {
-        BreezeDynamoDBConfig(region: .useast1, tableName: "Breeze", keyName: "itemKey", endpoint: "http://localstack:4566")
-    }
-}
 
 @main
 struct BreezeLambdaItemAPI {
     static func main() async throws {
 #if DEBUG
         do {
-            let lambdaAPIService = try await BreezeLambdaAPI<Item>(apiConfig: APIConfiguration())
+            let config = ConfigReader(
+                providers: [
+                    EnvironmentVariablesProvider(),
+                    try await FileProvider<JSONSnapshot>(filePath: "Sources/BreezeLambdaItemAPI/Resources/breeze-item-config.json")
+                ]
+            )
+            let configuration = BreezeAPIConfiguration(reader: config)
+            let lambdaAPIService = try await BreezeLambdaAPI<Item>(apiConfig: configuration)
             try await lambdaAPIService.run()
         } catch {
             print(error.localizedDescription)

Sources/BreezeLambdaItemAPI/Resources/breeze-item-config.json

@@ -0,0 +1,8 @@
+{
+  "_HANDLER": "BreezeLambdaItemAPI.create",
+  "AWS_REGION": "us-east-1",
+  "DYNAMO_DB_TABLE_NAME": "Breeze",
+  "DYNAMO_DB_KEY": "itemKey",
+  "LOCALSTACK_ENDPOINT": "http://localstack:4566",
+  "BREEZE_DB_TIMEOUT": 30
+}