Allow bearer token authentication in OpaConfiguration

README.md

@@ -36,6 +36,37 @@ DesiredResponse response = client.queryForDocument(new QueryForDocumentRequest(y
 // Do whatever you like with the response
 ```
 
+### Setting Headers
+
+You can add headers that will be included in all requests to the OPA server:
+
+```java
+// Add a single header
+OpaClient client = OpaClient.builder()
+                     .opaConfiguration("http://localhost:8181")
+                     .header("X-API-Key", "your-api-key")
+                     .header("Authorization", "Bearer your-token")
+                     .build();
+
+// Add multiple headers at once
+Map<String, String> headers = new HashMap<>();
+headers.put("X-API-Key", "your-api-key");
+headers.put("X-Tenant-ID", "tenant-123");
+headers.put("Authorization", "Bearer your-token");
+
+OpaClient client = OpaClient.builder()
+                     .opaConfiguration("http://localhost:8181")
+                     .headers(headers)
+                     .build();
+
+// You can also combine both approaches
+OpaClient client = OpaClient.builder()
+                     .opaConfiguration("http://localhost:8181")
+                     .headers(headers)
+                     .header("X-Request-ID", "req-456")
+                     .build();
+```
+
 ### Query for a list of documents
 
 This requires [commons-lang3](https://mvnrepository.com/artifact/org.apache.commons/commons-lang3) to be present on your classpath.

examples/query-for-document/src/main/java/com/bisnode/opa/XmasHappening.java

@@ -16,24 +16,26 @@ public class XmasHappening {
     public static final String NAME_QUERY_PATH = "name_rule/access_to_chimney";
     public static final String OPA_URL = "http://localhost:8181/";
 
-
     public static void main(String[] args) {
 
-
         List<OpaInput> sleighCrew = List.of(
                 new OpaInput("SantaClaus", 99, SantaPartyMember.SANTA.name()),
                 new OpaInput("Buddy", 17, SantaPartyMember.ELF.name()),
-                new OpaInput("Grinch",22, SantaPartyMember.GRINCH.name()),
+                new OpaInput("Grinch", 22, SantaPartyMember.GRINCH.name()),
                 new OpaInput("Rudolf", 33, SantaPartyMember.REINDEER.name()),
                 new OpaInput("Niko", 25, SantaPartyMember.REINDEER.name()));
 
         sleighCrew.forEach(XmasHappening::callOpa);
 
     }
 
-    static void callOpa(OpaInput testInput){
+    static void callOpa(OpaInput testInput) {
         log.info("Creating query for input {}", testInput);
-        OpaQueryApi queryApi = OpaClient.builder().opaConfiguration(OPA_URL).build();
+        OpaQueryApi queryApi = OpaClient.builder()
+                .opaConfiguration(OPA_URL)
+                .header("X-API-Key", "secret-key-12345")
+                .header("X-Request-Source", "xmas-app")
+                .build();
 
         QueryForDocumentRequest ageRequest = new QueryForDocumentRequest(testInput, AGE_QUERY_PATH);
         OpaOutput ageResponse = queryApi.queryForDocument(ageRequest, OpaOutput.class);

src/main/java/com/bisnode/opa/client/OpaClient.java

@@ -1,6 +1,5 @@
 package com.bisnode.opa.client;
 
-
 import com.bisnode.opa.client.data.OpaDataApi;
 import com.bisnode.opa.client.data.OpaDataClient;
 import com.bisnode.opa.client.data.OpaDocument;
@@ -16,11 +15,14 @@
 
 import java.lang.reflect.ParameterizedType;
 import java.net.http.HttpClient;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 
 /**
- * Opa client featuring {@link OpaDataApi}, {@link OpaQueryApi} and {@link OpaPolicyApi}
+ * Opa client featuring {@link OpaDataApi}, {@link OpaQueryApi} and
+ * {@link OpaPolicyApi}
  */
 public class OpaClient implements OpaQueryApi, OpaDataApi, OpaPolicyApi {
 
@@ -75,20 +77,71 @@ public void createOrUpdatePolicy(OpaPolicy policy) {
     public static class Builder {
         private OpaConfiguration opaConfiguration;
         private ObjectMapper objectMapper;
+        private Map<String, String> headers = new HashMap<>();
 
         /**
          * @param url URL including protocol and port
          */
         public Builder opaConfiguration(String url) {
-            this.opaConfiguration = new OpaConfiguration(url);
+            this.opaConfiguration = new OpaConfiguration(url, HttpClient.Version.HTTP_1_1, headers);
             return this;
         }
 
+        /**
+         * @param objectMapper ObjectMapper to be used for JSON
+         *                     serialization/deserialization
+         */
         public Builder objectMapper(ObjectMapper objectMapper) {
             this.objectMapper = objectMapper;
             return this;
         }
 
+        /**
+         * Add a header that will be included in all requests to the OPA server
+         *
+         * @param name  header name
+         * @param value header value
+         * @return this builder instance
+         */
+        public Builder header(String name, String value) {
+            Objects.requireNonNull(name, "Header name cannot be null");
+            Objects.requireNonNull(value, "Header value cannot be null");
+            this.headers.put(name, value);
+            // Recreate configuration if it already exists to include the new header
+            if (this.opaConfiguration != null) {
+                this.opaConfiguration = new OpaConfiguration(
+                        this.opaConfiguration.getUrl(),
+                        this.opaConfiguration.getHttpVersion(),
+                        this.headers);
+            }
+            return this;
+        }
+
+        /**
+         * Add multiple headers that will be included in all requests to the OPA
+         * server
+         *
+         * @param headers map of header names to values
+         * @return this builder instance
+         */
+        public Builder headers(Map<String, String> headers) {
+            if (headers != null) {
+                headers.forEach((name, value) -> {
+                    Objects.requireNonNull(name, "Header name cannot be null");
+                    Objects.requireNonNull(value, "Header value cannot be null");
+                });
+                this.headers.putAll(headers);
+                // Recreate configuration if it already exists to include the new headers
+                if (this.opaConfiguration != null) {
+                    this.opaConfiguration = new OpaConfiguration(
+                            this.opaConfiguration.getUrl(),
+                            this.opaConfiguration.getHttpVersion(),
+                            this.headers);
+                }
+            }
+            return this;
+        }
+
         public OpaClient build() {
             Objects.requireNonNull(opaConfiguration, "build() called without opaConfiguration provided");
             HttpClient httpClient = HttpClient.newBuilder()
@@ -97,7 +150,8 @@ public OpaClient build() {
             ObjectMapper objectMapper = Optional.ofNullable(this.objectMapper)
                     .orElseGet(ObjectMapperFactory.getInstance()::create);
             OpaRestClient opaRestClient = new OpaRestClient(opaConfiguration, httpClient, objectMapper);
-            return new OpaClient(new OpaQueryClient(opaRestClient), new OpaDataClient(opaRestClient), new OpaPolicyClient(opaRestClient));
+            return new OpaClient(new OpaQueryClient(opaRestClient), new OpaDataClient(opaRestClient),
+                    new OpaPolicyClient(opaRestClient));
         }
     }
 }

src/main/java/com/bisnode/opa/client/OpaConfiguration.java

@@ -3,6 +3,9 @@
 import java.beans.ConstructorProperties;
 import java.net.URI;
 import java.net.http.HttpClient;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
 import java.util.Objects;
 
 /**
@@ -11,26 +14,45 @@
 public final class OpaConfiguration {
     private final String url;
     private final HttpClient.Version httpVersion;
+    private final Map<String, String> headersMap;
 
     /**
-     * @param url base URL to OPA server, containing protocol, and port (eg. http://localhost:8181)
+     * @param url base URL to OPA server, containing protocol, and port (eg.
+     *            http://localhost:8181)
      */
-    @ConstructorProperties({"url"})
+    @ConstructorProperties({ "url" })
     public OpaConfiguration(String url) {
         this.url = url;
-        this.httpVersion = "https".equals(URI.create(url).getScheme()) ?
-                HttpClient.Version.HTTP_2 :
-                HttpClient.Version.HTTP_1_1;
+        this.httpVersion = "https".equals(URI.create(url).getScheme()) ? HttpClient.Version.HTTP_2
+                : HttpClient.Version.HTTP_1_1;
+        this.headersMap = Collections.emptyMap();
     }
 
     /**
-     * @param url base URL to OPA server, containing protocol, and port (eg. http://localhost:8181)
+     * @param url         base URL to OPA server, containing protocol, and port (eg.
+     *                    http://localhost:8181)
      * @param httpVersion preferred HTTP version to use for the client
      */
-    @ConstructorProperties({"url", "httpVersion"})
+    @ConstructorProperties({ "url", "httpVersion" })
     public OpaConfiguration(String url, HttpClient.Version httpVersion) {
         this.url = url;
         this.httpVersion = httpVersion;
+        this.headersMap = Collections.emptyMap();
+    }
+
+    /**
+     * @param url         base URL to OPA server, containing protocol, and port
+     *                    (eg.
+     *                    http://localhost:8181)
+     * @param httpVersion preferred HTTP version to use for the client
+     * @param headers     headers to be added to all requests
+     */
+    @ConstructorProperties({ "url", "httpVersion", "headers" })
+    public OpaConfiguration(String url, HttpClient.Version httpVersion, Map<String, String> headers) {
+        this.url = url;
+        this.httpVersion = httpVersion;
+        this.headersMap = headers != null ? Collections.unmodifiableMap(new HashMap<>(headers))
+                : Collections.emptyMap();
     }
 
     /**
@@ -41,7 +63,8 @@ public String getUrl() {
     }
 
     /**
-     * Get HTTP version configured for the client. If not configured will use HTTP2 for "https" scheme
+     * Get HTTP version configured for the client. If not configured will use HTTP2
+     * for "https" scheme
      * and HTTP1.1 for "http" scheme.
      *
      * @return httpVersion configured for use by the client
@@ -50,23 +73,38 @@ public HttpClient.Version getHttpVersion() {
         return this.httpVersion;
     }
 
+    /**
+     * Get headers that will be added to all requests
+     *
+     * @return unmodifiable map of headers
+     */
+    public Map<String, String> getHeaders() {
+        return this.headersMap;
+    }
+
     @Override
     public boolean equals(Object o) {
-        if (this == o) return true;
-        if (o == null || getClass() != o.getClass()) return false;
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
         OpaConfiguration that = (OpaConfiguration) o;
-        return Objects.equals(url, that.url);
+        return Objects.equals(url, that.url) &&
+                Objects.equals(httpVersion, that.httpVersion) &&
+                Objects.equals(headersMap, that.headersMap);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(url);
+        return Objects.hash(url, httpVersion, headersMap);
     }
 
     @Override
     public String toString() {
         return "OpaConfiguration{" +
                 "url='" + url + '\'' +
+                ", httpVersion=" + httpVersion +
+                ", headers=" + headersMap +
                 '}';
     }
 }

src/main/java/com/bisnode/opa/client/rest/OpaRestClient.java

@@ -29,18 +29,25 @@ public OpaRestClient(OpaConfiguration opaConfiguration, HttpClient httpClient, O
     }
 
     /**
-     * Create {@link java.net.http.HttpRequest.Builder} with configured url using provided endpoint
+     * Create {@link java.net.http.HttpRequest.Builder} with configured url using
+     * provided endpoint
      *
      * @param endpoint desired opa endpoint
      * @throws OpaClientException if URL or endpoint is invalid
      */
     public HttpRequest.Builder getBasicRequestBuilder(String endpoint) {
         OpaUrl url = OpaUrl.of(opaConfiguration.getUrl(), endpoint).normalized();
-        return HttpRequest.newBuilder(url.toUri());
+        HttpRequest.Builder requestBuilder = HttpRequest.newBuilder(url.toUri());
+
+        // Add headers from configuration
+        opaConfiguration.getHeaders().forEach(requestBuilder::header);
+
+        return requestBuilder;
     }
 
     /**
-     * Gets {@link java.net.http.HttpRequest.BodyPublisher} that is capable of serializing to JSON
+     * Gets {@link java.net.http.HttpRequest.BodyPublisher} that is capable of
+     * serializing to JSON
      *
      * @param body object to be serialized
      */
@@ -51,15 +58,16 @@ public HttpRequest.BodyPublisher getJsonBodyPublisher(Object body) throws JsonPr
     /**
      * Gets {@link JsonBodyHandler} that will deserialize JSON to desired class type
      *
-     * @param responseType desired  response type
+     * @param responseType desired response type
      * @param <T>          desired response type
      */
     public <T> JsonBodyHandler<T> getJsonBodyHandler(JavaType responseType) {
         return new JsonBodyHandler<>(responseType, objectMapper);
     }
 
     /**
-     * Sends provided request and returns response mapped using {@link java.net.http.HttpResponse.BodyHandler}
+     * Sends provided request and returns response mapped using
+     * {@link java.net.http.HttpResponse.BodyHandler}
      *
      * @param request     request to be sent
      * @param bodyHandler handler that indicates how to transform incoming body
@@ -68,11 +76,13 @@ public <T> JsonBodyHandler<T> getJsonBodyHandler(JavaType responseType) {
      * @throws IOException          is propagated from {@link HttpClient}
      * @throws InterruptedException is propagated from {@link HttpClient}
      */
-    public <T> HttpResponse<T> sendRequest(HttpRequest request, HttpResponse.BodyHandler<T> bodyHandler) throws IOException, InterruptedException {
+    public <T> HttpResponse<T> sendRequest(HttpRequest request, HttpResponse.BodyHandler<T> bodyHandler)
+            throws IOException, InterruptedException {
         try {
             HttpResponse<T> response = httpClient.send(request, bodyHandler);
             if (response.statusCode() >= 300) {
-                throw new OpaClientException("Error in communication with OPA server, status code: " + response.statusCode());
+                throw new OpaClientException(
+                        "Error in communication with OPA server, status code: " + response.statusCode());
             }
             return response;
         } catch (SocketException exception) {

src/test/groovy/com/bisnode/opa/client/ManagingDocumentSpec.groovy

@@ -93,4 +93,30 @@ class ManagingDocumentSpec extends Specification {
           thrown(OpaServerConnectionException)
 
     }
+
+    def 'should include headers in document requests'() {
+        given:
+          def documentPath = 'somePath'
+          def endpoint = "/v1/data/$documentPath"
+          def headerName = 'X-API-Key'
+          def headerValue = 'secret-key-123'
+          def client = OpaClient.builder()
+                  .opaConfiguration(url)
+                  .header(headerName, headerValue)
+                  .build()
+          wireMockServer
+                  .stubFor(put(urlEqualTo(endpoint))
+                          .withHeader(ContentType.HEADER_NAME, equalTo(APPLICATION_JSON))
+                          .withHeader(headerName, equalTo(headerValue))
+                          .willReturn(aResponse()
+                                  .withStatus(200)
+                                  .withHeader(ContentType.HEADER_NAME, APPLICATION_JSON)
+                                  .withBody('{}')))
+        when:
+          client.createOrOverwriteDocument(new OpaDocument(documentPath, DOCUMENT))
+        then:
+          noExceptionThrown()
+          wireMockServer.verify(putRequestedFor(urlEqualTo(endpoint))
+                  .withHeader(headerName, equalTo(headerValue)))
+    }
 }