AICORE_SERVICE_KEY in .env file (#129)

* Allow File Path in AI Core Env Var

* Sonarlint

* Documentation

* Update README.md

Co-authored-by: Alexander Dümont <[email protected]>

* Accept both env var and .env

* Updated doc

* Apply suggestions from code review

Co-authored-by: Alexander Dümont <[email protected]>

* Do not use System.getenv anymore

* Fix links

* ℹ️ The environment variable has priority over the `.env` file.

---------

Co-authored-by: Alexander Dümont <[email protected]>

Author: CharlesDuboisSAP

README.md

@@ -12,7 +12,7 @@
 - [Introduction](#introduction)
 - [General Requirements](#general-requirements)
 - [Connecting to SAP AI Core](#connecting-to-sap-ai-core)
-    - [Option 1: Set Credentials as Environment Variable](#option-1-set-credentials-as-environment-variable)
+    - [Option 1: Set Credentials as Environment Variable](#option-1-set-ai-core-credentials)
     - [Option 2: Regular Service Binding in SAP BTP Cloud Foundry](#option-2-regular-service-binding-in-sap-btp-cloud-foundry)
     - [Option 3: Define and Use a Destination](#option-3-define-and-use-a-destination)
 - [Getting Started](#getting-started)
@@ -64,7 +64,7 @@ There are multiple ways to provide these credentials:
 
 | Option | Description                                                                                              |
 |--------|----------------------------------------------------------------------------------------------------------|
-| **1**  | Set an environment variable explicitly: `AICORE_SERVICE_KEY`                                             |
+| **1**  | Create an `.env` file containing an `AICORE_SERVICE_KEY={...}`                                           |
 | **2**  | Regular service binding in SAP BTP Cloud Foundry (results in `VCAP_SERVICES` environment variable entry) |
 | **3**  | Define and use a _Destination_ in the SAP BTP Destination Service                                        |
 
@@ -75,7 +75,7 @@ Additional methods (not recommended for production):
 - Leverage a "user-provided" service binding
 - Define and use a custom `ServiceBinding` or `ServiceBindingAccessor` in your application
 
-### Option 1: Set Credentials as Environment Variable
+### Option 1: Set AI Core Credentials
 
 <details>
 <summary>Click to view detailed steps</summary>
@@ -87,16 +87,33 @@ Additional methods (not recommended for production):
 - Navigate to **Instances and Subscriptions** -> **Instances** -> **AI Core**
 - Click **View Credentials** and copy the JSON content
 
-**2. Set Environment Variable:**
+**2. Create `.env` file:**
+
+- Create an `.env` file in the root directory of your application
+- Add an entry `AICORE_SERVICE_KEY='<content-of-service-key>'`
+
+<details>
+<summary>Set an environment variable instead of .env</summary>
+
+**2. Set an Environment Variable: (alternative)**
 
 - In your IDE or terminal, set the environment variable `AICORE_SERVICE_KEY` with the copied JSON content
 
-Example:
+  ℹ️ The environment variable has priority over the `.env` file.
+
+Example Linux/MacOS:
 
 ```shell
 export AICORE_SERVICE_KEY='{ "clientid": "...", "clientsecret": "...", "url": "...", "serviceurls": { "AI_API_URL": "..." } }'
 ```
 
+Example Windows:
+
+```shell
+$env:AICORE_SERVICE_KEY='{ "clientid": "...", "clientsecret": "...", "url": "...", "serviceurls": { "AI_API_URL": "..." } }'
+```
+
+</details>
 </details>
 
 ### Option 2: Regular Service Binding in SAP BTP Cloud Foundry
@@ -180,7 +197,7 @@ Before you begin, ensure you have:
 - Met the OpenAI Chat Completion module specific requirements
     - Refer to [Prerequisites for OpenAI Chat Completion](docs/guides/OPENAI_CHAT_COMPLETION.md#prerequisites)
 - Set up the AI Core credentials
-  using [(1) Environment Variable](#option-1-set-credentials-as-environment-variable)
+  using [(1) Environment variable or env-file](#option-1-set-ai-core-credentials)
   or [(2) Regular Service Binding](#option-2-regular-service-binding-in-sap-btp-cloud-foundry).
 - Deployed the OpenAI GPT-3.5 Turbo model in SAP AI Core.
     - Refer to [Deploying the OpenAI GPT-3.5 Turbo Model](docs/guides/OPENAI_CHAT_COMPLETION.md#usage)

core/pom.xml

@@ -98,6 +98,10 @@
       <groupId>io.vavr</groupId>
       <artifactId>vavr</artifactId>
     </dependency>
+    <dependency>
+      <groupId>io.github.cdimascio</groupId>
+      <artifactId>dotenv-java</artifactId>
+    </dependency>
     <!-- scope "runtime" -->
     <dependency>
       <groupId>com.sap.cloud.sdk.cloudplatform</groupId>

core/src/main/java/com/sap/ai/sdk/core/AiCoreService.java

@@ -15,6 +15,7 @@
 import com.sap.cloud.sdk.cloudplatform.connectivity.exception.DestinationAccessException;
 import com.sap.cloud.sdk.cloudplatform.connectivity.exception.DestinationNotFoundException;
 import com.sap.cloud.sdk.services.openapi.apiclient.ApiClient;
+import io.github.cdimascio.dotenv.Dotenv;
 import java.util.NoSuchElementException;
 import java.util.function.BiFunction;
 import java.util.function.Function;
@@ -104,7 +105,7 @@ protected void destinationSetHeaders(@Nonnull final DefaultHttpDestination.Build
    */
   @Nonnull
   public AiCoreService withDestination(@Nonnull final Destination destination) {
-    baseDestinationHandler = (service) -> destination;
+    baseDestinationHandler = service -> destination;
     return this;
   }
 
@@ -160,7 +161,7 @@ public AiCoreDeployment forDeploymentByScenario(@Nonnull final String scenarioId
   @Nonnull
   protected Destination getBaseDestination()
       throws DestinationAccessException, DestinationNotFoundException {
-    val serviceKey = System.getenv("AICORE_SERVICE_KEY");
+    val serviceKey = Dotenv.configure().ignoreIfMissing().load().get("AICORE_SERVICE_KEY");
     return DestinationResolver.getDestination(serviceKey);
   }
 

core/src/main/java/com/sap/ai/sdk/core/DestinationResolver.java

@@ -22,11 +22,13 @@
 import javax.annotation.Nullable;
 import lombok.AccessLevel;
 import lombok.Getter;
+import lombok.NoArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
 import lombok.val;
 
 /** Utility class to resolve the destination pointing to the AI Core service. */
 @Slf4j
+@NoArgsConstructor(access = AccessLevel.PRIVATE) // utility class should not be instantiated
 class DestinationResolver {
   static final String AI_CLIENT_TYPE_KEY = "URL.headers.AI-Client-Type";
   static final String AI_CLIENT_TYPE_VALUE = "AI SDK Java";

core/src/test/java/com/sap/ai/sdk/core/AiCoreServiceTest.java

@@ -25,7 +25,7 @@
 import org.junit.jupiter.api.AfterEach;
 import org.junit.jupiter.api.Test;
 
-public class AiCoreServiceTest {
+class AiCoreServiceTest {
 
   // setup
   private static final Map<String, Object> URLS = Map.of("AI_API_URL", "https://srv");

pom.xml

@@ -64,6 +64,7 @@
     <system-stubs.version>2.1.3</system-stubs.version>
     <surefire.version>3.5.1</surefire.version>
     <springframework.version>6.1.14</springframework.version>
+    <dotenv-java.version>3.0.0</dotenv-java.version>
     <mockito.version>5.14.2</mockito.version>
     <!--  Quality assurance  -->
     <enforcer.skipBanLoggingFrameworks>false</enforcer.skipBanLoggingFrameworks>
@@ -92,6 +93,11 @@
         <artifactId>spring-web</artifactId>
         <version>${springframework.version}</version>
       </dependency>
+      <dependency>
+        <groupId>io.github.cdimascio</groupId>
+        <artifactId>dotenv-java</artifactId>
+        <version>${dotenv-java.version}</version>
+      </dependency>
       <!-- scope "test" -->
       <dependency>
         <groupId>org.junit.jupiter</groupId>