feat: log route errors to config manager (#43)

* feat: add dead letter channel for sending error information to the ConfigManager

* chore: log error if sending error logs to ConfigManager fails

* refactor: rename ErrorDto to RouteError

* fix: set HTTP method to POST for sending error logs to ConfigManager

* docs: update CHANGELOG.md

* docs: increase version in POM

CHANGELOG.md

@@ -2,7 +2,11 @@
 
 All notable changes to this project will be documented in this file.
 
-## [1.1.2] - 
+## [1.2.0] - 2021-06-28
+
+### Added
+
+- Log errors during route execution to the Configuration Manager.
 
 ### Changed
 

pom.xml

@@ -36,7 +36,7 @@
 
     <properties>
         <!-- General -->
-        <revision>1.1.2</revision>
+        <revision>1.2.0</revision>
         <email>[email protected]</email>
 
         <!-- Build info -->

src/main/java/de/fraunhofer/isst/dataspaceconnector/camel/config/context/ErrorHandlerConfig.java

@@ -0,0 +1,28 @@
+package de.fraunhofer.isst.dataspaceconnector.camel.config.context;
+
+import org.apache.camel.builder.DeadLetterChannelBuilder;
+import org.apache.camel.processor.errorhandler.RedeliveryPolicy;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Configuration;
+
+/**
+ * Defines beans required for error handling.
+ */
+@Configuration
+public class ErrorHandlerConfig {
+
+    /**
+     * Returns a DeadLetterChannelBuilder instance that routes all failed exchanges to the
+     * designated error handler route.
+     *
+     * @return the DeadLetterChannelBuilder
+     */
+    @Bean
+    public DeadLetterChannelBuilder errorHandler() {
+        final var dlcBuilder = new DeadLetterChannelBuilder();
+        dlcBuilder.setDeadLetterUri("direct:deadLetterChannel");
+        dlcBuilder.setRedeliveryPolicy(new RedeliveryPolicy().disableRedelivery());
+        return dlcBuilder;
+    }
+
+}

src/main/java/de/fraunhofer/isst/dataspaceconnector/camel/errorhandling/DeadLetterChannel.java

@@ -0,0 +1,44 @@
+package de.fraunhofer.isst.dataspaceconnector.camel.errorhandling;
+
+import org.apache.camel.Exchange;
+import org.apache.camel.builder.RouteBuilder;
+import org.springframework.beans.factory.annotation.Value;
+import org.springframework.stereotype.Component;
+
+/**
+ * Defines the route used for handling errors, which will send an error description to the
+ * Configuration Manager endpoint defined in application.properties.
+ */
+@Component
+public class DeadLetterChannel extends RouteBuilder {
+
+    /**
+     * The Configuration Manager endpoint for logging errors.
+     */
+    @Value("${config-manager.error-api.url}")
+    private String errorLogEndpoint;
+
+    /**
+     * Configures the error route. The error route uses a processor to create an {@link RouteError}
+     * and then sends this to the Configuration Manager.
+     *
+     * @throws Exception if an error occurs writing the ErrorDto as JSON.
+     */
+    @Override
+    public void configure() throws Exception {
+        onException(Exception.class)
+                .process(exchange -> {
+                    final var cause = exchange
+                            .getProperty(Exchange.EXCEPTION_CAUGHT, Exception.class);
+                    log.warn("Failed to send error logs to Configuration Manager: {}",
+                            cause.getMessage());
+                })
+                .handled(true);
+
+        from("direct:deadLetterChannel")
+                .process("dlcProcessor")
+                .setHeader(Exchange.HTTP_METHOD, constant("POST"))
+                .to(errorLogEndpoint);
+    }
+
+}

src/main/java/de/fraunhofer/isst/dataspaceconnector/camel/errorhandling/DeadLetterChannelProcessor.java

@@ -0,0 +1,42 @@
+package de.fraunhofer.isst.dataspaceconnector.camel.errorhandling;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import lombok.extern.log4j.Log4j2;
+import org.apache.camel.Exchange;
+import org.apache.camel.Processor;
+import org.springframework.stereotype.Component;
+
+/**
+ * Prepares an {@link RouteError} for a failed exchange.
+ */
+@Component("dlcProcessor")
+@Log4j2
+public class DeadLetterChannelProcessor implements Processor {
+
+    /**
+     * Writes the ErrorDto as JSON.
+     */
+    private final ObjectMapper objectMapper = new ObjectMapper();
+
+    /**
+     * Reads the route's ID, the endpoint where the exchange failed and the exception that caused
+     * the failure from an Exchange object and creates an {@link RouteError}. The ErrorDto is set as
+     * the body of the exchange's message.
+     *
+     * @param exchange the failed exchange.
+     * @throws Exception if an error occurs writing the error DTO as JSON.
+     */
+    @Override
+    public void process(final Exchange exchange) throws Exception {
+        final var routeId = exchange.getProperty("CamelFailureRouteId", String.class);
+        final var failureEndpoint = exchange.getProperty("CamelFailureEndpoint", String.class);
+        final var cause = exchange.getProperty(Exchange.EXCEPTION_CAUGHT, Exception.class);
+
+        final var errorDto = new RouteError(routeId, failureEndpoint, cause.getMessage());
+
+        log.warn("Caught an exception during route execution: {}", errorDto);
+
+        exchange.getIn().setBody(objectMapper.writeValueAsString(errorDto));
+    }
+
+}

src/main/java/de/fraunhofer/isst/dataspaceconnector/camel/errorhandling/RouteError.java

@@ -0,0 +1,32 @@
+package de.fraunhofer.isst.dataspaceconnector.camel.errorhandling;
+
+import lombok.AllArgsConstructor;
+import lombok.Getter;
+import lombok.Setter;
+import lombok.ToString;
+
+/**
+ * DTO for sending error information to the Configuration Manager.
+ */
+@Getter
+@Setter
+@AllArgsConstructor
+@ToString
+public class RouteError {
+
+    /**
+     * ID of the route where an error occurred.
+     */
+    private String routeId;
+
+    /**
+     * The endpoint where the error occurred.
+     */
+    private String endpoint;
+
+    /**
+     * The exception message.
+     */
+    private String message;
+
+}

src/main/resources/application.properties

@@ -18,3 +18,6 @@ server.ssl.key-alias=1
 # HTTP component truststore
 http.truststore.path=classpath:truststore.p12
 http.truststore.password=password
+
+# Configuration Manager
+config-manager.error-api.url=http://localhost:8081/api/ui/route/error