Add Healthcheck (#6)

* add healthcheck and basic docs

* fix linting

Dockerfile

@@ -16,6 +16,7 @@ WORKDIR /opt/hl7-to-kafka
 COPY --from=build /home/gradle/src/dependencies/ ./
 COPY --from=build /home/gradle/src/spring-boot-loader/ ./
 COPY --from=build /home/gradle/src/application/ ./
+COPY HealthCheck.java .
 
 ARG GIT_REF=""
 ARG GIT_URL=""
@@ -27,8 +28,7 @@ EXPOSE 8080 2575
 
 ENTRYPOINT ["java", "-XX:MaxRAMPercentage=90", "org.springframework.boot.loader.launch.JarLauncher"]
 
-HEALTHCHECK --interval=25s --timeout=3s --retries=2 \
-    CMD curl --fail --silent localhost:8080/actuator/health | grep UP || exit 1
+HEALTHCHECK --interval=25s --timeout=3s --retries=2 CMD ["java", "HealthCheck.java", "||", "exit", "1"]
 
 LABEL org.opencontainers.image.created=${BUILD_TIME} \
     org.opencontainers.image.authors="Sebastian Stöcker" \

HealthCheck.java

@@ -0,0 +1,27 @@
+import java.io.IOException;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse.BodyHandlers;
+
+public class HealthCheck {
+
+    private static final int STATUS_OK = 200;
+
+    public static void main(String[] args)
+        throws InterruptedException, IOException {
+
+        var client = HttpClient.newHttpClient();
+        var request = HttpRequest
+            .newBuilder()
+            .uri(URI.create("http://localhost:8080/actuator/health"))
+            .header("accept", "application/json")
+            .build();
+        var response = client.send(request, BodyHandlers.ofString());
+        if (response.statusCode() != STATUS_OK || !response
+            .body()
+            .contains("UP")) {
+            throw new RuntimeException("Healthcheck failed");
+        }
+    }
+}

README.md

@@ -0,0 +1,54 @@
+# hl7-to-kafka
+[![MegaLinter](https://github.com/diz-unimr/hl7-to-kafka/actions/workflows/mega-linter.yml/badge.svg?branch=main)](https://github.com/diz-unimr/hl7-to-kafka/actions/workflows/mega-linter.yml?query=branch%3Amain) ![java](https://github.com/diz-unimr/hl7-to-kafka/actions/workflows/build.yml/badge.svg) ![docker](https://github.com/diz-unimr/hl7-to-kafka/actions/workflows/release.yml/badge.svg) [![codecov](https://codecov.io/gh/diz-unimr/hl7-to-kafka/graph/badge.svg?token=6vQBSuFCH3)](https://codecov.io/gh/diz-unimr/hl7-to-kafka)
+
+> HL7 v2 to Kafka producer
+
+This project consist of a HL7v2 MLLP listener, which transfers received
+messages to a Kafka topic.
+
+Messages are passed to a Kafka producer and send to a configured topic
+without any mapping. The sender receives an acknowledgement message (ACK) of
+each message sent.
+
+## <a name="deploy_config"></a> Configuration
+
+The following environment variables can be set:
+
+endpoint:
+  kafka.topic: hl7-topic
+  hl7:
+    port: 2575
+    encoding: iso-8859-1
+
+| Variable                 | Default        | Description                                                    |
+|--------------------------|----------------|----------------------------------------------------------------|
+| BOOTSTRAP_SERVERS        | localhost:9092 | Kafka brokers                                                  |
+| SECURITY_PROTOCOL        | PLAINTEXT      | Kafka communication protocol                                   |
+| SSL_TRUST_STORE_PASSWORD |                | Truststore password (if using `SECURITY_PROTOCOL=SSL`)         |
+| SSL_KEY_STORE_PASSWORD   |                | Keystore password (if using `SECURITY_PROTOCOL=SSL`)           |
+| SSL_TRUST_STORE_PASSWORD |                | Truststore password (if using `SECURITY_PROTOCOL=SSL`)         |
+| ENDPOINT_KAFKA_TOPIC     | hl7-topic      | Kafka output topic to send HL7 messages to                     |
+| ENDPOINT_HL7_PORT        | 2575           | HL7 MLLP listener port                                         |
+| ENDPOINT_HL7_ENCODING    | iso-8859-1     | Default encoding to use if not specified in the message header |
+| LOG_LEVEL                | info           | Log level (error, warn, info, debug)                           |
+
+Additional application properties can be set by overriding values form the [application.yaml](src/main/resources/application.yaml) by using environment variables.
+
+## Error handling
+
+> TODO
+
+
+## Development
+
+A [test setup](dev/compose.yaml) and a [script](dev/send-hl7.sh) to send an example
+message is available for development purposes.
+
+### Builds
+
+Available image tags can be found at the [Container Registry](https://github.com/orgs/diz-unimr/packages?repo_name=hl7-to-kafka) or under
+[Releases](https://github.com/diz-unimr/hl7-to-kafka/releases).
+
+## License
+
+[AGPL-3.0](https://www.gnu.org/licenses/agpl-3.0.en.html)

src/main/resources/application.yaml

@@ -1,12 +1,12 @@
 # the name of Camel
 camel:
-  main.name: HL7 to Kafka
+  springboot.name: hl7-to-kafka
   component:
     kafka:
-      brokers: localhost:9092
-      ssl-endpoint-algorithm: PLAINTEXT
-      ssl-truststore-password:
-      ssl-keystore-password:
+      brokers: ${BOOTSTRAP_SERVERS:localhost:9092}
+      ssl-endpoint-algorithm: ${SECURITY_PROTOCOL:PLAINTEXT}
+      ssl-truststore-password: ${SSL_TRUST_STORE_PASSWORD}
+      ssl-keystore-password: ${SSL_KEY_STORE_PASSWORD}
 
 endpoint:
   kafka.topic: hl7-topic