How to Monitor Docker Containers with Prometheus and Grafana?

Monitoring Docker containers is very important for keeping our applications working well. When we use Prometheus and Grafana, we can collect data, see it clearly, and understand how our Docker containers are doing. Prometheus helps us monitor and send alerts. Grafana gives us a simple dashboard to show the data we collect. This helps us keep an eye on how our containers perform.

In this article, we will show how to monitor Docker containers with Prometheus and Grafana. We will talk about what we need to set up monitoring. We will also explain how to configure Prometheus for Docker monitoring. Then we will see how to visualize Docker metrics with Grafana. We will look at how to gather Docker metrics using cAdvisor. Lastly, we will share some helpful Grafana dashboards made for Docker monitoring. We will also answer some common questions to help you understand the monitoring process better.

  • How Can You Monitor Docker Containers with Prometheus and Grafana?
  • What Are the Prerequisites for Monitoring Docker Containers?
  • How to Set Up Prometheus for Docker Monitoring?
  • How to Configure Grafana for Visualizing Docker Metrics?
  • How to Collect Docker Metrics Using cAdvisor?
  • What Are Some Useful Grafana Dashboards for Docker Monitoring?
  • Frequently Asked Questions

What Are the Prerequisites for Monitoring Docker Containers?

To monitor Docker containers with Prometheus and Grafana, we need to meet some basic requirements. Here is a simple list of what we need:

  1. Docker Installation: First, we need to install Docker on our host machine. Make sure Docker is running. We can follow the guide on how to install Docker on different operating systems.

  2. Prometheus: Next, we should install Prometheus. It helps us scrape and store metrics from our Docker containers. We can download it from Prometheus’s official site.

  3. Grafana: Then, we need to install Grafana. It helps us see the metrics that Prometheus collects. We can get Grafana from Grafana’s official site.

  4. cAdvisor: We also need to deploy cAdvisor. It collects metrics from the containers. cAdvisor shows us how much resources the containers use and their performance. We can run it as a Docker container like this:

    docker run -d \
  --name=cadvisor \
  --volume=/var/run:/var/run:rw \
  --volume=/sys:/sys:ro \
  --volume=/var/lib/docker:/var/lib/docker:ro \
  -p 8080:8080 \
  google/cadvisor:latest

  5. Network Configuration: We must check the network settings. Prometheus needs to access the metrics from cAdvisor. By default, cAdvisor shows metrics on port 8080.

  6. Prometheus Configuration: We need to create a prometheus.yml file. This file helps Prometheus know where to scrape metrics from cAdvisor:

    global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'cadvisor'
    static_configs:
      - targets: ['<YOUR_CADVISOR_IP>:8080']

  7. Grafana Datasource Configuration: Finally, we need to add Prometheus as a data source in Grafana. Here are the settings we should use:

    • URL: http://<YOUR_PROMETHEUS_IP>:9090
    • Access: Server (default)

When we set up and configure these components correctly, we can monitor our Docker containers using Prometheus and Grafana.

How to Set Up Prometheus for Docker Monitoring?

To set up Prometheus for Docker monitoring, we can follow these steps:

  1. Create a Docker Network (this is optional but helps with isolation):

    docker network create monitoring

  2. Run Prometheus: First, we need to make a prometheus.yml configuration file. Here is what we should put in it:

    global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'docker'
    static_configs:
      - targets: ['cadvisor:8080']

    Now, we can run the Prometheus container with this command:

    docker run -d \
  --name=prometheus \
  --network=monitoring \
  -p 9090:9090 \
  -v $(pwd)/prometheus.yml:/etc/prometheus/prometheus.yml \
  prom/prometheus

  3. Run cAdvisor to collect Docker metrics:

    docker run -d \
  --name=cadvisor \
  --network=monitoring \
  -p 8080:8080 \
  --volume=/:/rootfs:ro \
  --volume=/var/run:/var/run:rw \
  --volume=/sys:/sys:ro \
  --volume=/var/lib/docker/:/var/lib/docker:ro \
  google/cadvisor:latest

  4. Access Prometheus: We should open our web browser and go to http://localhost:9090. We will see the Prometheus UI. There we can start to query metrics from Docker containers.

  5. Verify the Setup: We can check if cAdvisor metrics are being scraped. To do this, we run this query in the Prometheus UI:

    up{job="docker"}

This setup helps us to monitor Docker containers using Prometheus well. For more info on Docker and how it works, we can look at articles like What is Docker and Why Should You Use It? and How to Install Docker on Different Operating Systems.

How to Configure Grafana for Visualizing Docker Metrics?

We can set up Grafana to see Docker metrics that Prometheus collects. Here are the steps to do it:

  1. Install Grafana: If we don’t have Grafana installed, we can run it using Docker:

    docker run -d -p 3000:3000 grafana/grafana

  2. Access Grafana: Open your web browser and go to http://localhost:3000. The default login info is:

    • Username: admin
    • Password: admin (it will ask you to change it after first login)

  3. Add Prometheus as a Data Source:

    • Click on the gear icon (⚙️) on the left side to open the Configuration menu.
    • Choose Data Sources and click on Add data source.
    • Pick Prometheus from the list.
    • In the HTTP part, set the URL to your Prometheus server, like http://localhost:9090.
    • Click on Save & Test to check if Grafana can connect to Prometheus.

  4. Create a Dashboard:

    • Click on the “+” icon in the sidebar and choose Dashboard.
    • Click on Add new panel.

  5. Add Metrics:

    • In the new panel, choose Prometheus as the data source.
    • In the Query section, we can enter a Prometheus query to show Docker metrics. For example:
    rate(container_cpu_usage_seconds_total{image!="",container_name!="POD"}[5m])

    This query shows how much CPU each container is using.

  6. Configure Visualization:

    • Choose the kind of visualization we want (like Graph, Gauge, Table) from the choices.
    • Change the settings for the visualization if we need to (like axes, legend, thresholds).

  7. Save the Dashboard:

    • After we set up the panels and visualizations, click on the Save dashboard icon (diskette icon) at the top.
    • Give a name to your dashboard and click Save.

  8. Explore Pre-built Dashboards:

    • Grafana has many ready-made dashboards. We can find them in the Dashboard section by clicking on Import.
    • We can enter the ID of popular dashboards from Grafana’s dashboard repository, like:
      • Docker Monitoring: 893
      • cAdvisor Monitoring: 8935

By following these steps, we can easily set up Grafana to see Docker metrics. This setup helps us watch how our Docker containers perform in real-time. We get useful info about resource use and other important metrics.

How to Collect Docker Metrics Using cAdvisor?

To monitor Docker containers well, cAdvisor (Container Advisor) is a great tool. It gives us insights into how containers use resources and their performance. Let’s see how we can set it up and use it to collect Docker metrics.

Step 1: Pull the cAdvisor Docker Image

First, we need to pull the cAdvisor image from Docker Hub:

docker pull google/cadvisor:latest

Step 2: Run cAdvisor Container

Next, we run cAdvisor in a Docker container. We should map the right ports and bind mount the Docker socket. This will let cAdvisor access Docker metrics:

docker run -d \
  --name=cadvisor \
  --volume=/:/rootfs:ro \
  --volume=/var/run:/var/run:rw \
  --volume=/sys:/sys:ro \
  --volume=/var/lib/docker/:/var/lib/docker:ro \
  -p 8080:8080 \
  google/cadvisor:latest

Step 3: Access cAdvisor Dashboard

After we start cAdvisor, we can access the dashboard. Just go to http://<YOUR_HOST_IP>:8080 in any web browser. There, we can see metrics like CPU usage, memory usage, network I/O, and filesystem usage for each running container.

Step 4: Integrate cAdvisor with Prometheus

To collect metrics from cAdvisor using Prometheus, we need to add cAdvisor as a target in our Prometheus configuration file (prometheus.yml):

scrape_configs:
  - job_name: 'cadvisor'
    static_configs:
      - targets: ['<YOUR_HOST_IP>:8080']

Step 5: Restart Prometheus

After we update the configuration, we should restart our Prometheus server to make changes apply:

docker restart <prometheus_container_name>

Step 6: Visualize Metrics in Grafana

Once Prometheus is collecting metrics from cAdvisor, we can see these metrics in Grafana. We need to add Prometheus as a data source in Grafana and create dashboards with the metrics we got from cAdvisor.

By doing these steps, we can collect and see Docker metrics using cAdvisor, Prometheus, and Grafana. This helps us monitor our containers better.

For more details on Docker monitoring, we can check this Docker Monitoring Tutorial.

What Are Some Useful Grafana Dashboards for Docker Monitoring?

We can use Grafana to monitor Docker containers. It has many dashboards that help us with this. Here are some good Grafana dashboards for Docker monitoring:

  1. Docker Overview Dashboard
    • This dashboard shows overall Docker metrics. It includes container status, CPU usage, memory usage, and network I/O.
    • Dashboard ID: 893. We can import it through Grafana’s dashboard settings.
    {
  "id": 893,
  "title": "Docker Overview",
  "url": "https://grafana.com/grafana/dashboards/893"
}
  2. cAdvisor Dashboard
    • This dashboard shows detailed metrics from cAdvisor about how containers use resources.
    • Dashboard ID: 893. We can import it from the Grafana dashboard management page.
    {
  "id": 893,
  "title": "cAdvisor",
  "url": "https://grafana.com/grafana/dashboards/893"
}
  3. Docker Container Metrics
    • This dashboard monitors metrics for each container. It shows CPU, memory, network, and disk usage.
    • Dashboard ID: 179. We can easily import it via Grafana.
    {
  "id": 179,
  "title": "Docker Container Metrics",
  "url": "https://grafana.com/grafana/dashboards/179"
}
  4. Docker Swarm Monitoring
    • This is a full dashboard for monitoring Docker Swarm clusters. It shows node states, service health, and resource usage.
    • Dashboard ID: 1122. We can import it.
    {
  "id": 1122,
  "title": "Docker Swarm Monitoring",
  "url": "https://grafana.com/grafana/dashboards/1122"
}
  5. Node Exporter Full
    • This dashboard helps us monitor the host system that runs Docker containers and shows Docker metrics too.
    • Dashboard ID: 1860. We can import it using Grafana’s dashboard feature.
    {
  "id": 1860,
  "title": "Node Exporter Full",
  "url": "https://grafana.com/grafana/dashboards/1860"
}

To use these dashboards: - We go to Grafana, click the “+” icon, and select “Import”. - We enter the dashboard ID or upload the JSON file if we have it. - We need to set up our data sources to see the metrics.

For more information about Docker and best ways to monitor it, we can read How to Monitor Docker Containers with Prometheus and Grafana.

Frequently Asked Questions

1. How do we monitor Docker containers with Prometheus and Grafana?

To monitor Docker containers with Prometheus and Grafana, we need to set up Prometheus to get metrics from our Docker containers. We can use tools like cAdvisor to collect these metrics. Then, Prometheus can retrieve them. We can configure Grafana to display these metrics. This way, we can make dashboards that show the performance and health of our Docker containers.

2. What is cAdvisor and how does it help in Docker monitoring?

cAdvisor (Container Advisor) is a free tool that gives us information about how our containers are performing. It collects and shares metrics like CPU, memory, file system, and network usage. When we use cAdvisor with Prometheus, we can monitor our Docker containers better. This helps us see how resources are used and how performance changes over time.

3. What are the prerequisites for using Prometheus and Grafana with Docker?

Before we can use Prometheus and Grafana for Docker monitoring, we must have Docker installed on our system. We also need to install Prometheus and Grafana, plus any exporters like cAdvisor. It is important to know some Docker commands and how to set up Prometheus and Grafana. This will help us see our Docker metrics clearly.

4. How can we configure Grafana to visualize Docker metrics?

To set up Grafana for showing Docker metrics, we must add Prometheus as a data source in Grafana. After that, we can create dashboards using queries to get metrics from Prometheus that come from Docker containers. Grafana gives us many ways to visualize, like graphs and charts, so we can show our metrics in easy to understand ways.

5. What are some useful Grafana dashboards for monitoring Docker containers?

There are many ready-made Grafana dashboards for monitoring Docker containers. These dashboards usually have panels for CPU usage, memory use, network traffic, and more. They give us a full view of container performance. We can find community dashboards on Grafana’s official site or GitHub. We can import and change them to fit our monitoring needs.

For more insights into Docker and its parts, we can look at these resources: - What is Docker and Why Should You Use It? - How to Install Docker on Different Operating Systems - What is Containerization and How Does it Relate to Docker?

These articles can help us understand Docker better. This will make our monitoring with Prometheus and Grafana work better too.