Add custom header support for Azure OpenAI

- Adds configuration properties to allow custom header specification
- Implements mechanism to apply custom headers to Azure OpenAI requests
- Enhances flexibility for users to customize API interactions

These changes allow users to add necessary headers for authentication,
tracking, or other purposes when interacting with Azure OpenAI services.

Resolves https://github.com/spring-projects/spring-ai/issues/1284

spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/azure/openai/AzureOpenAiAutoConfiguration.java

@@ -16,6 +16,8 @@
 package org.springframework.ai.autoconfigure.azure.openai;
 
 import java.util.List;
+import java.util.Map;
+import java.util.stream.Collectors;
 
 import org.springframework.ai.azure.openai.AzureOpenAiAudioTranscriptionModel;
 import org.springframework.ai.azure.openai.AzureOpenAiChatModel;
@@ -40,6 +42,7 @@ import com.azure.core.credential.AzureKeyCredential;
 import com.azure.core.credential.KeyCredential;
 import com.azure.core.credential.TokenCredential;
 import com.azure.core.util.ClientOptions;
+import com.azure.core.util.Header;
 
 /**
  * @author Piotr Olaszewski
@@ -57,14 +60,19 @@ public class AzureOpenAiAutoConfiguration {
 	@Bean
 	@ConditionalOnMissingBean({ OpenAIClient.class, TokenCredential.class })
 	public OpenAIClient openAIClient(AzureOpenAiConnectionProperties connectionProperties) {
-
 		if (StringUtils.hasText(connectionProperties.getApiKey())) {
 
 			Assert.hasText(connectionProperties.getEndpoint(), "Endpoint must not be empty");
 
+			Map<String, String> customHeaders = connectionProperties.getCustomHeaders();
+			List<Header> headers = customHeaders.entrySet()
+				.stream()
+				.map(entry -> new Header(entry.getKey(), entry.getValue()))
+				.collect(Collectors.toList());
+			ClientOptions clientOptions = new ClientOptions().setApplicationId(APPLICATION_ID).setHeaders(headers);
 			return new OpenAIClientBuilder().endpoint(connectionProperties.getEndpoint())
 				.credential(new AzureKeyCredential(connectionProperties.getApiKey()))
-				.clientOptions(new ClientOptions().setApplicationId(APPLICATION_ID))
+				.clientOptions(clientOptions)
 				.buildClient();
 		}
 

spring-ai-spring-boot-autoconfigure/src/main/java/org/springframework/ai/autoconfigure/azure/openai/AzureOpenAiConnectionProperties.java

@@ -1,5 +1,5 @@
 /*
- * Copyright 2023 - 2024 the original author or authors.
+ * Copyright 2023-2024 the original author or authors.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -13,8 +13,12 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package org.springframework.ai.autoconfigure.azure.openai;
 
+import java.util.HashMap;
+import java.util.Map;
+
 import org.springframework.boot.context.properties.ConfigurationProperties;
 
 @ConfigurationProperties(AzureOpenAiConnectionProperties.CONFIG_PREFIX)
@@ -40,6 +44,8 @@ public class AzureOpenAiConnectionProperties {
 	 */
 	private String endpoint;
 
+	private Map<String, String> customHeaders = new HashMap<>();
+
 	public String getEndpoint() {
 		return this.endpoint;
 	}
@@ -64,4 +70,12 @@ public class AzureOpenAiConnectionProperties {
 		this.openAiApiKey = openAiApiKey;
 	}
 
+	public Map<String, String> getCustomHeaders() {
+		return customHeaders;
+	}
+
+	public void setCustomHeaders(Map<String, String> customHeaders) {
+		this.customHeaders = customHeaders;
+	}
+
 }

spring-ai-spring-boot-autoconfigure/src/test/java/org/springframework/ai/autoconfigure/azure/AzureOpenAiAutoConfigurationIT.java

@@ -15,6 +15,9 @@
  */
 package org.springframework.ai.autoconfigure.azure;
 
+import com.azure.ai.openai.OpenAIClient;
+import com.azure.ai.openai.implementation.OpenAIClientImpl;
+import com.azure.core.http.*;
 import org.junit.jupiter.api.Test;
 import org.junit.jupiter.api.condition.EnabledIfEnvironmentVariable;
 import org.springframework.ai.autoconfigure.azure.openai.AzureOpenAiAutoConfiguration;
@@ -34,15 +37,6 @@ import org.springframework.boot.test.context.runner.ApplicationContextRunner;
 import org.springframework.core.io.ClassPathResource;
 import org.springframework.core.io.Resource;
 import org.springframework.util.ReflectionUtils;
-
-import com.azure.ai.openai.OpenAIClient;
-import com.azure.ai.openai.implementation.OpenAIClientImpl;
-import com.azure.core.http.HttpHeader;
-import com.azure.core.http.HttpHeaderName;
-import com.azure.core.http.HttpMethod;
-import com.azure.core.http.HttpPipeline;
-import com.azure.core.http.HttpRequest;
-import com.azure.core.http.HttpResponse;
 import reactor.core.publisher.Flux;
 
 import java.lang.reflect.Field;