Create a telemetry backend

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

Before you begin

You have a running instance of Red Hat OpenShift Dev Spaces.
You have a telemetry server deployed to receive events. See Create a telemetry server.

About this task

Note:

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

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 Content from github.com is not included.GitHub packages for the latest version of backend-base and add the following dependencies to your pom.xml:

<!-- Required -->
<dependency>
    <groupId>org.eclipse.che.incubator.workspace-telemetry</groupId>
    <artifactId>backend-base</artifactId>
    <version><latest_version></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 Content from docs.github.com is not included.GitHub packages and add your GitHub username, the token, and che-incubator repository details in your ~/.m2/settings.xml file:

<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><github_username></username>
         <password><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:

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")
    Optional<String> welcomeMessage;
}

where:

@ConfigProperty(name = "welcome.message"): A MicroProfile configuration annotation that injects 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:

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(
            (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);
    }

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

    @Override
    public void onActivity() {}
}

where:

ifPresentOrElse(): Log the welcome message if it was provided.
LOG.info("The received event is: {}", event): 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 org.my.group.AnalyticsManager and org.my.group.MainConfiguration:
```
quarkus.arc.selected-alternatives=MainConfiguration,AnalyticsManager
```

Results

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