file/file-source-with-transforms/README.adoc

# Camel-Kafka-connector File Source

## Introduction

This is an example for Camel-Kafka-connector File source

## What is needed

- A File System

## Running Kafka

```
$KAFKA_HOME/bin/zookeeper-server-start.sh $KAFKA_HOME/config/zookeeper.properties
$KAFKA_HOME/bin/kafka-server-start.sh $KAFKA_HOME/config/server.properties
$KAFKA_HOME/bin/kafka-topics.sh --create --bootstrap-server localhost:9092 --replication-factor 1 --partitions 1 --topic mytopic
```

## Setting up the needed bits and running the example

You'll need to setup the plugin.path property in your kafka

Open the `$KAFKA_HOME/config/connect-standalone.properties`

and set the `plugin.path` property to your choosen location

You'll need to build your connector starting from an archetype:

```
> mvn archetype:generate  -DarchetypeGroupId=org.apache.camel.kafkaconnector.archetypes  -DarchetypeArtifactId=camel-kafka-connector-extensible-archetype  -DarchetypeVersion=0.10.1
[INFO] Scanning for projects...
[INFO] 
[INFO] ------------------< org.apache.maven:standalone-pom >-------------------
[INFO] Building Maven Stub Project (No POM) 1
[INFO] --------------------------------[ pom ]---------------------------------
[INFO] 
[INFO] >>> maven-archetype-plugin:3.1.2:generate (default-cli) > generate-sources @ standalone-pom >>>
[INFO] 
[INFO] <<< maven-archetype-plugin:3.1.2:generate (default-cli) < generate-sources @ standalone-pom <<<
[INFO] 
[INFO] 
[INFO] --- maven-archetype-plugin:3.1.2:generate (default-cli) @ standalone-pom ---
[INFO] Generating project in Interactive mode
[INFO] Archetype repository not defined. Using the one from [org.apache.camel.kafkaconnector.archetypes:camel-kafka-connector-extensible-archetype:0.10.1] found in catalog remote
Define value for property 'groupId': org.apache.camel.kafkaconnector
Define value for property 'artifactId': file-extended
Define value for property 'version' 1.0-SNAPSHOT: : 0.10.1
Define value for property 'package' org.apache.camel.kafkaconnector: : 
Define value for property 'camel-kafka-connector-name': camel-file-kafka-connector
[INFO] Using property: camel-kafka-connector-version = 0.10.1
Confirm properties configuration:
groupId: org.apache.camel.kafkaconnector
artifactId: file-extended
version: 0.10.1
package: com.github.oscerd
camel-kafka-connector-name: camel-file-kafka-connector
camel-kafka-connector-version: 0.10.1
 Y: : Y
[INFO] ----------------------------------------------------------------------------
[INFO] Using following parameters for creating project from Archetype: camel-kafka-connector-extensible-archetype:0.10.1
[INFO] ----------------------------------------------------------------------------
[INFO] Parameter: groupId, Value: org.apache.camel.kafkaconnector
[INFO] Parameter: artifactId, Value: file-extended
[INFO] Parameter: version, Value: 0.10.1
[INFO] Parameter: package, Value: org.apache.camel.kafkaconnector
[INFO] Parameter: packageInPathFormat, Value: org/apache/camel/kafkaconnector
[INFO] Parameter: package, Value: org.apache.camel.kafkaconnector
[INFO] Parameter: version, Value: 0.10.1
[INFO] Parameter: groupId, Value: org.apache.camel.kafkaconnector
[INFO] Parameter: camel-kafka-connector-name, Value: camel-file-kafka-connector
[INFO] Parameter: camel-kafka-connector-version, Value: 0.10.1
[INFO] Parameter: artifactId, Value: ftps-extended
[INFO] Project created from Archetype in dir: /home/workspace/miscellanea/file-extended
[INFO] ------------------------------------------------------------------------
[INFO] BUILD SUCCESS
[INFO] ------------------------------------------------------------------------
[INFO] Total time:  24.590 s
[INFO] Finished at: 2020-11-05T07:45:43+01:00
[INFO] ------------------------------------------------------------------------
> cd /home/workspace/miscellanea/file-extended
```

We'll need to add a little transform for this example. So import the file-extended project in your IDE and create a class in the only package there

```
package org.apache.camel.kafkaconnector;

import java.io.File;
import java.io.IOException;
import java.nio.charset.StandardCharsets;
import java.util.Map;

import org.apache.camel.component.file.GenericFile;
import org.apache.camel.kafkaconnector.utils.SchemaHelper;
import org.apache.commons.io.FileUtils;
import org.apache.kafka.common.config.ConfigDef;
import org.apache.kafka.connect.connector.ConnectRecord;
import org.apache.kafka.connect.transforms.Transformation;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class FileTransforms<R extends ConnectRecord<R>> implements Transformation<R> {
    public static final String FIELD_KEY_CONFIG = "key";
    public static final ConfigDef CONFIG_DEF = new ConfigDef().define(FIELD_KEY_CONFIG, ConfigDef.Type.STRING, null, ConfigDef.Importance.MEDIUM, "Transforms File to String");

    private static final Logger LOG = LoggerFactory.getLogger(FileTransforms.class);

    @Override
    public R apply(R r) {
        Object value = r.value();

        if (r.value() instanceof GenericFile) {
            LOG.debug("Converting record from RemoteFile to text");
            GenericFile<File> message = (GenericFile<File>)r.value();
            String c = null;
            try {
                c = FileUtils.readFileToString(message.getFile(), StandardCharsets.UTF_8);
            } catch (IOException e) {
                e.printStackTrace();
            }

            return r.newRecord(r.topic(), r.kafkaPartition(), null, r.key(), SchemaHelper.buildSchemaBuilderForType(c), c, r.timestamp());

        } else {
            LOG.debug("Unexpected message type: {}", r.value().getClass());

            return r;
        }
    }

    @Override
    public ConfigDef config() {
        return CONFIG_DEF;
    }

    @Override
    public void close() {

    }

    @Override
    public void configure(Map<String, ?> map) {

    }
```

Now we need to build the connector:

```
> mvn clean package
```

In this example we'll use `/home/oscerd/connectors/` as plugin.path, but we'll need the generated tar.gz from the previois build

```
> cd /home/oscerd/connectors/
> cp /home/workspace/miscellanea/file-extended/target/file-extended-0.10.1-package.tar.gz .
> untar.gz file-extended-0.10.1-package.tar.gz
```

Now it's time to setup the connectors

Open the File connector configuration file

```
name=CamelFileSourceConnector
connector.class=org.apache.camel.kafkaconnector.file.CamelFileSourceConnector
key.converter=org.apache.kafka.connect.storage.StringConverter
transforms=FileTransformer
transforms.FileTransformer.type=org.apache.camel.kafkaconnector.FileTransforms

camel.source.maxPollDuration=10000

topics=mytopic

camel.source.path.directoryName=/tmp/kafkastuff/
camel.source.endpoint.idempotent=true
camel.source.endpoint.noop=true
```

Now you can run the example

```
$KAFKA_HOME/bin/connect-standalone.sh $KAFKA_HOME/config/connect-standalone.properties config/CamelFileSourceConnector.properties
```

Create files into the /tmp/kafkastuff folder with the content "Hello from ckc"

On a different terminal run the kafka-consumer and you should see messages from the SQS queue arriving through Kafka Broker.

```
bin/kafka-console-consumer.sh --bootstrap-server localhost:9092 --topic mytopic --from-beginning
{"schema":{"type":"string","optional":false},"payload":"Hello from ckc"}
% Reached end of topic mytopic [0] at offset 1
```