Textual debug for Camel routes allows to set breakpoints at Route definition.

The Debug Adapter for Apache Camel VS Code extension latest release 0.1.1 supports JMX connection. It opens the possibility to start a Camel application with Camel textual route debugging activated in a single VS Code launch configuration. I thought it would be a five minutes effort but it was a several hours search to configure a not-yet-perfect solution. I hope that sharing the current state will save you few hours! Let’s see the different configurations required to achieve it.

How to configure VS Code

Minimal Camel version

Check that Camel 3.16+ is used.

camel-debug on classpath

camel-debug must be on the classpath for the debug session. As it should not be used in production, a good way to achieve it is to use a Maven profile, for instance:

<profiles>
    <profile>
        <id>camel.debug</id>
        <activation>
            <property>
                <name>camel.debug</name>
                <value>true</value>
            </property>
        </activation>
        <dependencies>
            <dependency>
                 <groupId>org.apache.camel</groupId>
                <artifactId>camel-debug</artifactId>
            </dependency>
        </dependencies>
    </profile>
</profiles>

VS Code task to start application

Next step consist in providing a VS Code task to start the Camel application with camel-debug on the classpath by using the camel.debug profile mentioned in previous point.

In .settings/tasks.json (the file might need to be created), you need to add this kind of task:

{
	"version": "2.0.0",
	"tasks": [
		{
			"label": "Run Camel application with debug Profile",
			"type": "shell",
			"command": "mvn", // mvn binary of Maven must be available on command-line
			"args": [
				"camel:run",
				"-Pcamel.debug" // This depends on your project. The goal here is to have camel-debug on the classpath.
			],
			"problemMatcher": { // Problem matcher is mandatory to avoid a dialog warning on each launch but cannot find a good way to configure it
				"owner": "camel",
				"pattern": {
					"regexp": "^.*$"
				},
				"severity": "error",
				"source": "maven",
				"background": {
					"activeOnStart": true,
					"beginsPattern": "^.*$",
					"endsPattern": "^.*$"
				}
			},
			"presentation": {
				"reveal": "always"
			},
			"isBackground": true // Must be set as background as the Maven commands doesn't return until the Camel application stops.
		}
	]
}

Launch configuration to Attach debugger and start application

The idea here is to provide a Launch configuration which will do both: start the Camel application and attach the Camel debugger.

In .settings/launch.json (the file might need to be created), you need to add this kind of configuration:

{
	"version": "0.2.0",
	"configurations": [
		{
			"name": "Run with Camel Debugger",
			"type": "apache.camel",
			"request": "attach",
			"preLaunchTask": "Run Camel application with debug Profile" // This must match the label provided as task
		}
	]
}

On slow connection, it might not work the first time as the timeout to connect the debugger will be hit. It is not yet configurable, just relaunch it.

Run & Debug

Last action is to call the Launch configuration. If you have a single launch configuration, hitting F5 should work. Otherwise, you can go to the Run and Debug panel and then Run & Debug the launch configuration that you just configured.

Time to set breakpoints and enjoy!

Resources

Here you can see a branch of the Camel Main example with metadata preconfigured for VS Code.

I created a short video to see all of that in action here.

What’s next

I really welcome feedback from VS Code advanced users. The main questions that I have in mind are:

• Are there better ways to handle this use case?
• How to configure properly the problemMatcher?
• Is it possible to stop the task launched in preLaunchTask when disconnecting the debugger (using the postDebugTask)?
• Are there ways to reuse vscode-maven execution commands instead of generic VS Code task of type shell?

Next step will be to provide completions to help combining these configurations. And then maybe providing a fully built-in specific launch configuration.

You can submit your enhancement requests on the VS Code client for Debug Adapter for Camel or in the Red Hat Jira.