Contents

• Overview
• Pre-requisites
• Installation & Configuration
  • Post Configuration
  • Import Dashboard
  • Alerting
  • Test Alerts
    • Service Down
    • High Load
• Security Considerations
• Troubleshooting
  • Mac Users

A Prometheus & Grafana demo

Here's a quick start tutorial using only docker and docker-compose to start-up a Prometheus demo on your local machine containing Prometheus, Grafana, cadvisor and node-exporter to monitor your Docker infrastructure and machine.

Prometheus and Grafana is a strong combo which can be used to monitor other things such as Kubernetes. If you want to know how to monitor Kubernetes and workloads with Prometheus take a look at Digital Oceans tutorial.

Pre-requisites

Before we get started setting up the Prometheus demo ensure you install the latest version of docker and docker-compose on your machine.

Currently the repo requires 18.06.0+ version of docker and 1.25.0+ of docker-compose as it uses version 3.7 of the compose file format.

You can check your versions by running docker --version and docker-compose --version

Installation & Configuration

Clone this project locally to your machine.

If you would like to change which targets should be monitored or make configuration changes edit the prometheus.yml file. The targets section is where you define what should be monitored by Prometheus. The names defined in this file are sourced from the service name in the docker-compose file. If you wish to change names of the services you can add the "container_name" parameter in the docker-compose.yml file.

This project has sensible defaults meaning that you can just go ahead and start it up by running the following command:

$ docker-compose up -d

The above command will collect the latest docker images of the projects used in this repo.

See what containers was started by running

$ docker ps

Grafana is now accessible via: http://localhost:3000

username - admin
password - foobar (Password is stored in the `config.monitoring` env file)

Post Configuration

Now we need to create the Prometheus Datasource in order to connect Grafana to Prometheus

• Click the Gear menu icon in the left side menu
• Click Add data source
• Fill the URL input box with http://prometheus:9090
• Click Save and Test.

Import Dashboard

There are Dashboard templates included in this demo within the dashboard folder, to use them you can import them into grafana.

Follow the step by step guide and use the images below it as a guide:

• Click the Plus sign menu icon in the left side menu
• Click Import
• Click Upload .json file
• Navigate to the dashboards folder and select a .json file to upload e.g. docker.json
• In the prometheus selection box select Prometheus
• Click import

The dashboards are intended to help you get started with monitoring using Prometheus. There are different dashboards included in this tutorial:

• Docker Dashboard based on cadvisor data - dashboards/docker.json
• Alerting Dashboard - dashboards/high-load-dashboard.json
• Prometheus 2 Dashboard - dashboards/high-load-dashboard.json
• System monitoring Dashboard based on node exporter - dashboards/system-monitoring.json

Alerting

Alerting has been added to the stack with Slack integration. Two Alerts have been pre-configured and can by seen in:

Alerts - prometheus/alert.rules Slack configuration - alertmanager/config.yml

The Slack configuration requires to build a custom integration.

• Open your slack team in your browser https://<your-slack-team>.slack.com/apps
• Click build in the upper right corner
• Choose Incoming Web Hooks link under Send Messages
• Click on the "incoming webhook integration" link
• Select which channel
• Click on Add Incoming WebHooks integration
• Copy the Webhook URL into the alertmanager/config.yml URL section
• Fill in Slack username and channel

View Prometheus alerts http://localhost:9090/alerts
View Alert Manager http://localhost:9093

Test Alerts

Service Down

A quick way to test the service down pre-configured alert is to stop a service.

• Stop the node-exporter container by running docker stop node_exporter.
• Check the alerts in both the Alert Manager http://localhost:9093 and Prometheus Alerts http://localhost:9090/alerts to understand how they flow through the system and what you can control where.
• The alert will start by being pending which can only be seen in Prometheus Alerts http://localhost:9090/alerts.
• This is because Prometheus will only sent the alert to Alert Manager http://localhost:9093 when it is active, which in this case will take 2 minutes due to the configuration in prometheus/alert.rules.
• You should notice shortly the alert arrive in Slack if you have configured the integration.
• To make everything go back to normal run docker-compose up -d.

High Load

This tutorial has a bash file to help testing high load. You can look trough it first to see what it, the short version is that it runs a busy loop on all your CPUs.

• To test the high load alert run ./alert.sh.
• Let this run for a few minutes and you will notice the load alert appear.
• Then press any key or Ctrl+C to cancel the script.

Security Considerations

This project is intended to be a quick-start to get up and running with Docker and Prometheus. Security has not been implemented in this project. It is the users responsability to implement sensible security practices.

Troubleshooting

It appears some people have reported no data appearing in Grafana. If this is happening to you be sure to check the time range being queried within Grafana to ensure it is using Today's date with current time.

Reset

If you want to get a clean start you can do a reset of this demo. To do a complete reset run ./reset.sh. This will delete everything created by this demo including the volumes holding persistent data.

Mac Users

The node-exporter does not run the same as Mac and Linux. Node-Exporter is not designed to run on Mac and in fact cannot collect metrics from the Mac OS due to the differences between Mac and Linux OS's. I recommend you comment out the node-exporter section in the docker-compose.yml file and instead just use the cAdvisor.