README

This readme explain how to remote debug metricbeat running on docker/kubernetes from your laptop with your local IDE.

Steps to run on docker:

0. Move into metricbeat folder from the root folder of this project. Note: For some reason even if we are building in a subfolder, the substitutePath.to is still pointing to our root folder.

cd metricbeat

1. cross build image for linux

GOOS=linux GOARCH=amd64 go build -gcflags "-N -l" -o metricbeat main.go

2. buld docker container

docker build -t metricbeat-debugger-image -f Dockerfile.debug .

3. run docker container

docker run -p 56268:56268 --network elastic-package-stack_default -v $(pwd)/metric.docker.yml:/usr/share/metricbeat/metricbeat.yml metricbeat-debugger-image -c /usr/share/metricbeat/metricbeat.yml -e

You can customize the metricbeat configuration by mounting a different file instead of $(pwd)/metric.docker.yml.

4. Attach to the remote debugger via your local IDE. Follow Attach to remote debugger

Steps to run on kubernetes:

Steps from 0 to 2 (included) are the same as Steps to run on docker

0. Move into metricbeat folder from the root folder of this project. Note: For some reason even if we are building in a subfolder, the substitutePath.to is still pointing to our root folder.

cd metricbeat

1. cross build image for linux

GOOS=linux GOARCH=amd64 go build -gcflags "-N -l" -o metricbeat main.go

2. buld docker container

docker build -t metricbeat-debugger-image -f Dockerfile.debug .

3. load image into Kind in order to run on kubernetes

kind load docker-image metricbeat-debugger-image:latest

4. Edit deploy/kubernetes/metricbeat-kubernetes.yaml with these changes

containers:
- name: metricbeat
  # image: docker.elastic.co/beats/metricbeat:8.2.0
  image: metricbeat-debugger-image:latest
  imagePullPolicy: Never
  args: [
    "-c", "/etc/metricbeat.yml",
    "-e",
    "--system.hostfs=/hostfs",
  ]
  ports:
    - containerPort: 56268
      hostPort: 56268
      protocol: TCP

Namely you need:

• change the docker image used
• add imagePullPolicy to pull the image from inside Kind
• add a ports to expose the port in order to remote debug from laptop

Compared to the docker example, here the metricbeat config is provided in the kubernetes manifest and mounted as a volume.

5. Apply the changes in kubernetes to run the metricbeat

kubectl apply -f metricbeat-kubernetes.yaml

6. Port forward from k8s to localhost

kubectl port-forward -n kube-system <pod-name> 56268:56268

where <pod-name> is the name of the pod running on k8s

7. Attach to the remote debugger via your local IDE. Follow Attach to remote debugger

Attach to remote debugger via your local IDE

Visual Studio Code

In order to attach to the remote debugger running on docker container or a k8s pod you need to provide a file .vscode/launch.json on your local machine with some configurations.

You can use the following template, but remember to replace <absolute path> with the absolute path of the root folder of your project.

{
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Connect to server",
            "type": "go",
            "request": "attach",
            "mode": "remote",
            "debugAdapter": "dlv-dap",
            "port": 56268,
            "host": "127.0.0.1",
            "showLog": true,
            "trace": "trace",
            "cwd": "${workspaceFolder}",
            "substitutePath": [
                {
	                "from": "${workspaceFolder}",
					        "to": "<absolute path>"
                }
            ]
        }

    ]
}

Goland/IntelliJ

More info at here