Create a telemetry backend

Create a Quarkus-based telemetry backend that extends the Che telemetry client and implements custom event handling logic.

For fast feedback when developing, develop inside a DevWorkspace. This way, you can run the application in a cluster and receive events from the front-end telemetry plugin.

Prerequisites

You have a running instance of Eclipse Che.
You have a telemetry server deployed to receive events. See Create a telemetry server.

Procedure

Create a Maven Quarkus project:

mvn io.quarkus:quarkus-maven-plugin:2.7.1.Final:create \
    -DprojectGroupId=mygroup -DprojectArtifactId=devworkspace-telemetry-example-plugin \
-DprojectVersion=1.0.0-SNAPSHOT

Remove the files under src/main/java/mygroup and src/test/java/mygroup.

Consult the GitHub packages for the latest version of backend-base and add the following dependencies to your pom.xml:

Example 1. pom.xml

<!-- Required -->
<dependency>
    <groupId>org.eclipse.che.incubator.workspace-telemetry</groupId>
    <artifactId>backend-base</artifactId>
    <version>LATEST VERSION FROM PREVIOUS STEP</version>
</dependency>


<!-- Used to make http requests to the telemetry server -->
<dependency>
    <groupId>io.quarkus</groupId>
    <artifactId>quarkus-rest-client</artifactId>
</dependency>
<dependency>
    <groupId>io.quarkus</groupId>
    <artifactId>quarkus-rest-client-jackson</artifactId>
</dependency>

Create a personal access token with read:packages permissions from GitHub packages and add your GitHub username, the token, and che-incubator repository details in your ~/.m2/settings.xml file:

Example 2. settings.xml

<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
  xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0
http://maven.apache.org/xsd/settings-1.0.0.xsd">
   <servers>
      <server>
         <id>che-incubator</id>
         <username>YOUR GITHUB USERNAME</username>
         <password>YOUR GITHUB TOKEN</password>
      </server>
   </servers>

   <profiles>
      <profile>
         <id>github</id>
         <activation>
            <activeByDefault>true</activeByDefault>
         </activation>
         <repositories>
            <repository>
               <id>central</id>
               <url>https://repo1.maven.org/maven2</url>
               <releases><enabled>true</enabled></releases>
               <snapshots><enabled>false</enabled></snapshots>
               </repository>
               <repository>
               <id>che-incubator</id>
               <url>https://maven.pkg.github.com/che-incubator/che-workspace-telemetry-client</url>
            </repository>
         </repositories>
      </profile>
   </profiles>
</settings>

Create MainConfiguration.java under src/main/java/mygroup. This file contains configuration provided to AnalyticsManager:

Example 3. MainConfiguration.java

package org.my.group;

import java.util.Optional;

import javax.enterprise.context.Dependent;
import javax.enterprise.inject.Alternative;

import org.eclipse.che.incubator.workspace.telemetry.base.BaseConfiguration;
import org.eclipse.microprofile.config.inject.ConfigProperty;

@Dependent
@Alternative
public class MainConfiguration extends BaseConfiguration {
    @ConfigProperty(name = "welcome.message")      (1)
    Optional<String> welcomeMessage;               (2)
}

1	A MicroProfile configuration annotation is used to inject the `welcome.message` configuration. For more details on how to set configuration properties specific to your backend, see the Quarkus Configuration Reference Guide.

Create AnalyticsManager.java under src/main/java/mygroup. This file contains logic specific to the telemetry system:

Example 4. AnalyticsManager.java

package org.my.group;

import java.util.HashMap;
import java.util.Map;

import javax.enterprise.context.Dependent;
import javax.enterprise.inject.Alternative;
import javax.inject.Inject;

import org.eclipse.che.incubator.workspace.telemetry.base.AbstractAnalyticsManager;
import org.eclipse.che.incubator.workspace.telemetry.base.AnalyticsEvent;
import org.eclipse.che.incubator.workspace.telemetry.finder.DevWorkspaceFinder;
import org.eclipse.che.incubator.workspace.telemetry.finder.UsernameFinder;
import org.eclipse.microprofile.rest.client.inject.RestClient;
import org.slf4j.Logger;

import static org.slf4j.LoggerFactory.getLogger;

@Dependent
@Alternative
public class AnalyticsManager extends AbstractAnalyticsManager {

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

    public AnalyticsManager(MainConfiguration mainConfiguration, DevWorkspaceFinder devworkspaceFinder, UsernameFinder usernameFinder) {
        super(mainConfiguration, devworkspaceFinder, usernameFinder);

        mainConfiguration.welcomeMessage.ifPresentOrElse(     (1)
            (str) -> LOG.info("The welcome message is: {}", str),
            () -> LOG.info("No welcome message provided")
        );
    }

    @Override
    public boolean isEnabled() {
        return true;
    }

    @Override
    public void destroy() {}

    @Override
    public void onEvent(AnalyticsEvent event, String ownerId, String ip, String userAgent, String resolution, Map<String, Object> properties) {
        LOG.info("The received event is: {}", event);         (2)
    }

    @Override
    public void increaseDuration(AnalyticsEvent event, Map<String, Object> properties) { }

    @Override
    public void onActivity() {}
}

1	Log the welcome message if it was provided.
2	Log the event received from the front-end plugin.

Add the quarkus.arc.selected-alternatives property to src/main/resources/application.properties to specify the alternative beans:
Example 5. application.properties
quarkus.arc.selected-alternatives=MainConfiguration,AnalyticsManager

Verification

Run the Quarkus application and verify that it starts without errors:
```
mvn quarkus:dev
```

Additional resources