Add http-event-listener.connect-http-headers.config-file property

Introduces the `http-event-listener.connect-http-headers.config-file`
property to allow defining custom HTTP headers in an external file
using `key=value` pairs. This supports header names and values
containing commas (`,`) or colons (`:`), which are not supported in
the inline `http-event-listener.connect-http-headers` property.

Only one of `http-event-listener.connect-http-headers` or
`http-event-listener.connect-http-headers.config-file` may be set.
An exception will be raised if both are configured.

Author: danielbelchior

docs/src/main/sphinx/admin/event-listeners-http.md

@@ -75,6 +75,12 @@ event-listener.config-files=etc/http-event-listener.properties,...
     [](http-event-listener-custom-headers) for more details
   - Empty
 
+* - http-event-listener.connect-http-headers.config-file
+  - Path of the config file containing a list of custom HTTP headers to be sent
+    along with the events. See [](http-event-listener-custom-headers) for more
+    details
+  - Empty
+
 * - http-event-listener.connect-http-method
   - Specifies the HTTP method to use for the request. Supported values
     are POST and PUT.
@@ -119,8 +125,23 @@ Providing headers follows the pattern of `key:value` pairs separated by commas:
 http-event-listener.connect-http-headers="Header-Name-1:header value 1,Header-Value-2:header value 2,..."
 ```
 
-If you need to use a comma(`,`) or colon(`:`) in a header name or value,
-escape it using a backslash (`\`).
+If your header names or values need to include special characters such as commas 
+(`,`) or colons (`:`),define them in an external configuration file using:
+
+```text
+http-event-listener.connect-http-headers.config-file=/path/to/headers.conf
+```
+
+The configuration file should contain one `key=value` pair per line, for example:
+
+```text
+Header-Name-1=header value 1
+Header-Name-2=header value with : colon and , comma
+```
+
+Only one of `http-event-listener.connect-http-headers` **or**
+`http-event-listener.connect-http-headers.config-file` can be used at a time.
+If both properties are set, the system will raise an exception during startup.
 
-Keep in mind that these are static, so they can not carry information
-taken from the event itself.
+Keep in mind that these headers are static—they cannot include information
+dynamically taken from the event itself.

plugin/trino-http-event-listener/pom.xml

@@ -157,6 +157,12 @@
             <scope>test</scope>
         </dependency>
 
+        <dependency>
+            <groupId>io.airlift</groupId>
+            <artifactId>testing</artifactId>
+            <scope>test</scope>
+        </dependency>
+
         <dependency>
             <groupId>io.trino</groupId>
             <artifactId>trino-main</artifactId>

plugin/trino-http-event-listener/src/main/java/io/trino/plugin/httpquery/HttpEventListener.java

@@ -19,9 +19,11 @@
 import com.google.common.util.concurrent.Futures;
 import com.google.inject.Inject;
 import io.airlift.bootstrap.LifeCycleManager;
+import io.airlift.configuration.validation.FileExists;
 import io.airlift.http.client.BodyGenerator;
 import io.airlift.http.client.HttpClient;
 import io.airlift.http.client.Request;
+import io.airlift.http.client.StatusResponseHandler.StatusResponse;
 import io.airlift.json.JsonCodec;
 import io.airlift.log.Logger;
 import io.airlift.units.Duration;
@@ -31,18 +33,24 @@
 import io.trino.spi.eventlistener.SplitCompletedEvent;
 import jakarta.annotation.PreDestroy;
 
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.IOException;
+import java.io.UncheckedIOException;
 import java.net.URI;
 import java.net.URISyntaxException;
 import java.util.Map;
+import java.util.Optional;
+import java.util.Properties;
 import java.util.concurrent.ScheduledExecutorService;
 import java.util.concurrent.TimeUnit;
 
 import static com.google.common.base.Verify.verify;
+import static com.google.common.collect.ImmutableMap.toImmutableMap;
 import static com.google.common.net.HttpHeaders.CONTENT_TYPE;
 import static com.google.common.net.MediaType.JSON_UTF_8;
 import static io.airlift.concurrent.Threads.daemonThreadsNamed;
 import static io.airlift.http.client.JsonBodyGenerator.jsonBodyGenerator;
-import static io.airlift.http.client.StatusResponseHandler.StatusResponse;
 import static io.airlift.http.client.StatusResponseHandler.createStatusResponseHandler;
 import static java.util.Objects.requireNonNull;
 import static java.util.concurrent.Executors.newSingleThreadScheduledExecutor;
@@ -73,6 +81,7 @@ public class HttpEventListener
     private final Duration maxDelay;
     private final double backoffBase;
     private final Map<String, String> httpHeaders;
+    private final Optional<@FileExists File> httpHeadersConfigFile;
     private final URI ingestUri;
     private final HttpEventListenerHttpMethod httpMethod;
     private final ScheduledExecutorService executor;
@@ -102,6 +111,7 @@ public HttpEventListener(
         this.backoffBase = config.getBackoffBase();
         this.httpMethod = config.getHttpMethod();
         this.httpHeaders = ImmutableMap.copyOf(config.getHttpHeaders());
+        this.httpHeadersConfigFile = config.getHttpHeadersConfigFile();
 
         try {
             ingestUri = new URI(config.getIngestUri());
@@ -145,13 +155,22 @@ public void splitCompleted(SplitCompletedEvent splitCompletedEvent)
 
     private void sendLog(BodyGenerator eventBodyGenerator, String queryId)
     {
-        Request request = Request.builder()
+        Request.Builder requestBuilder = Request.builder()
                 .setMethod(httpMethod.name())
-                .addHeaders(Multimaps.forMap(httpHeaders))
                 .addHeader(CONTENT_TYPE, JSON_UTF_8.toString())
                 .setUri(ingestUri)
-                .setBodyGenerator(eventBodyGenerator)
-                .build();
+                .setBodyGenerator(eventBodyGenerator);
+
+        httpHeadersConfigFile.ifPresentOrElse(
+                file -> {
+                    Map<String, String> fileHeaders = loadHttpHeadersFromFile(file);
+                    requestBuilder.addHeaders(Multimaps.forMap(fileHeaders));
+                },
+                () -> {
+                    requestBuilder.addHeaders(Multimaps.forMap(httpHeaders));
+                });
+
+        Request request = requestBuilder.build();
 
         attemptToSend(request, 0, Duration.valueOf("0s"), queryId);
     }
@@ -249,6 +268,22 @@ private Duration nextDelay(Duration delay)
         return newDuration;
     }
 
+    public static Map<String, String> loadHttpHeadersFromFile(File file)
+    {
+        Properties properties = new Properties();
+        try (FileInputStream fis = new FileInputStream(file)) {
+            properties.load(fis);
+        }
+        catch (IOException e) {
+            throw new UncheckedIOException("Failed to read HTTP headers config file: " + file, e);
+        }
+
+        return properties.entrySet().stream()
+                .collect(toImmutableMap(
+                        e -> e.getKey().toString(),
+                        e -> e.getValue().toString()));
+    }
+
     @Override
     public void shutdown()
     {

plugin/trino-http-event-listener/src/main/java/io/trino/plugin/httpquery/HttpEventListenerConfig.java

@@ -11,18 +11,23 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 package io.trino.plugin.httpquery;
 
 import com.google.common.collect.ImmutableMap;
 import io.airlift.configuration.Config;
 import io.airlift.configuration.ConfigDescription;
+import io.airlift.configuration.validation.FileExists;
 import io.airlift.units.Duration;
+import jakarta.validation.constraints.AssertTrue;
 import jakarta.validation.constraints.Min;
 import jakarta.validation.constraints.NotNull;
 
+import java.io.File;
 import java.util.EnumSet;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.stream.Collectors;
 
 public class HttpEventListenerConfig
@@ -35,6 +40,7 @@ public class HttpEventListenerConfig
     private String ingestUri;
     private HttpEventListenerHttpMethod httpMethod = HttpEventListenerHttpMethod.POST;
     private Map<String, String> httpHeaders = ImmutableMap.of();
+    private File httpHeadersConfigFile;
 
     @ConfigDescription("Will log io.trino.spi.eventlistener.QueryCreatedEvent")
     @Config("http-event-listener.log-created")
@@ -130,6 +136,20 @@ public HttpEventListenerConfig setHttpHeaders(List<String> httpHeaders)
         return this;
     }
 
+    public Optional<@FileExists File> getHttpHeadersConfigFile()
+    {
+        return Optional.ofNullable(httpHeadersConfigFile);
+    }
+
+    @Config("http-event-listener.connect-http-headers.config-file")
+    @ConfigDescription("Path to a properties file containing custom HTTP headers, " +
+            "specified as key-value pairs (one per line, e.g., Header-Name=Header Value)")
+    public HttpEventListenerConfig setHttpHeadersConfigFile(File httpHeadersConfigFile)
+    {
+        this.httpHeadersConfigFile = httpHeadersConfigFile;
+        return this;
+    }
+
     @ConfigDescription("Number of retries on server error")
     @Config("http-event-listener.connect-retry-count")
     public HttpEventListenerConfig setRetryCount(int retryCount)
@@ -184,4 +204,11 @@ public Duration getMaxDelay()
     {
         return this.maxDelay;
     }
+
+    @AssertTrue(message = "Exactly one of http-event-listener.connect-http-headers.config-file or " +
+            "http-event-listener.connect-http-headers must be set")
+    public boolean validateHeaderConfigRedundant()
+    {
+        return !(httpHeadersConfigFile != null && !httpHeaders.isEmpty());
+    }
 }