Simple monitoring with Beszel

What is Beszel

It is a lightweight monitoring platform including docker stats, alerts and a web UI. Take a look at the official documentation HERE

Why not Grafana + Prometheus

If you already have a Grafana + Prometheus stack, you are not missing out on anything. Beszel is a much simpler and lighter alternatives to Grafana+Prometheus. I personally have a full Prometheus + Grafana stack, but I wanted to give Beszel a try and I found it pretty nice.

If you currently have no monitoring stack, and you want something simple to get started with, I would recommend that you give Beszel a try. And if you find it lacking any features that you want, you can then think about Grafana + Prometheus. And if you would like to give Grafana + Prometheus a try, I have a post Setting up Prometheus and Grafana using Docker

How does it work

• Two components : Hub and Agents
• Hub is the backend that runs on a docker container.
• The agents runs on each machine we want to monitor. The Hub connects to the agent via ssh

Let's set it up

Step 1 : Install the Hub

Go to the host where you want to run the Hub. And create the docker compose file

mkdir beszel
cd beszel

Create compose.yml with the following content

services:
  beszel:
    image: henrygd/beszel:latest
    container_name: beszel
    restart: unless-stopped
    extra_hosts:
      - host.docker.internal:host-gateway
    ports:
      - 8090:8090
    volumes:
      - ./beszel_data:/beszel_data

  beszel-agent:
    image: henrygd/beszel-agent:latest
    container_name: beszel-agent
    restart: unless-stopped
    network_mode: host
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
    environment:
      PORT: 45876
      # Do not remove quotes around the key
      KEY: 'UPDATE WITH YOUR PUBLIC KEY (copy from "Add system" dialog)'

Bring it up

docker compose up -d

Step 2 : Setup the Agent

Now, go to your ip where beszel is running:8090 on a browser, create the admin user

From the "Add new system" dialog, copy the public key

Even though the "hub" and "agent" are running on the same docker stack, it uses ssh to communicate.

Back in your compose.yml for Beszel, add the ssh key to the KEY

Step 3 : Finish setting up the hub

Back on your web browser, fill in the name (can be any name). But, the Host/IP must be host.docker.internal

And click Add system

And that should be it!! You should be able to see the dashboard right away!

Step 4 : (Optional) Adding another system

To add a new system, go to your new instance you want to monitor

mkdir beszel-agent
cd beszel-agent

And create the agent compose.yml

services:
  beszel-agent:
    image: henrygd/beszel-agent
    container_name: beszel-agent
    restart: unless-stopped
    network_mode: host
    volumes:
      - /var/run/docker.sock:/var/run/docker.sock:ro
      # monitor other disks / partitions by mounting a folder in /extra-filesystems
      # - /mnt/disk1/.beszel:/extra-filesystems/disk1:ro
    environment:
      PORT: 45876
      KEY: '<public key>'

Now, back in Beszel dashboard, click on Add System (Top right) and

• fill in the details
  • Name: Can be anything
  • Host/IP : Ip address of the instance where Agent is running
• Copy the ssh public key
• Update the key in the KEY for the new agent's compose.yml (the one we just created)
• Do docker-compose up -d again on the new agent

About Firewall rules

The Hub is connecting to the agent. So if your network has firewall restrictions, you must allow the Hub to connect to any agent you wish to monitor over port 45876

For example, this is my firewall rule allowing DOCKER_HOSTS which is where Beszel hub is running

Closing thoughts

If you face any issues, take a look here