Docker Container Monitor - Monitoring Docker Container Status with Grafana

This comprehensive guide demonstrates how to build a complete Docker container monitoring system using Prometheus, Node Exporter, cAdvisor, and Grafana. We’ll cover creating Docker networks, preparing Prometheus configuration, deploying monitoring services with Docker Compose, and configuring Grafana data sources and dashboards to effectively monitor Docker container performance and status.

1. Deploy Grafana

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If you don’t already have a Grafana container running, check out the Grafana deployment guide.

2. Create a Docker Network

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To facilitate communication between Grafana, Loki, and Promtail containers, we’ll create a bridge network. If you have an alternative setup, feel free to skip to Step 3.

• You can create the network through Portainer’s network configuration interface.
• Or use the command:

docker network create grafana

3. Prepare Prometheus Directory and Configuration

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1. Create the following directory structure and files:

   /appdata/prometheus
   ├── config
   │   └── prometheus.yml
   └──  data

   • prometheus.yml

     # my global config
     global:
       scrape_interval: 15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
       evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
       # scrape_timeout is set to the global default (10s).
     
     # Alertmanager configuration
     alerting:
       alertmanagers:
       - scheme: http
         static_configs:
         - targets:
           - "alertmanager:9093"
     
     # Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
     #rule_files:
       # - "first_rules.yml"
       # - "second_rules.yml"
     
     # A scrape configuration containing exactly one endpoint to scrape:
     # Here it's Prometheus itself.
     scrape_configs:
       # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
       - job_name: 'prometheus'
         # Override the global default and scrape targets from this job every 5 seconds.
         scrape_interval: 5s
         static_configs:
              - targets: ['localhost:9090']
     
       - job_name: 'cadvisor'
         scrape_interval: 5s
         static_configs:
           - targets: ['cadvisor:8080']
     
       - job_name: 'node-exporter'
         scrape_interval: 5s
         static_configs:
           - targets: ['node-exporter:9100']

2. Update folder permissions

   Prometheus runs as user ID 65534 by default:

   sudo chown -R 65534:65534 /appdata/prometheus

4. Deploy Prometheus, Node Exporter, and cAdvisor

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• docker compose file

  services:
    cadvisor:
      container_name: cadvisor
      image: gcr.io/cadvisor/cadvisor:latest
      hostname: cadvisor
      restart: unless-stopped
      privileged: true
      networks:
        - grafana
      expose:
        - 8080
      command:
        - '-housekeeping_interval=15s'
        - '-docker_only=true'
        - '-store_container_labels=false'
      devices:
        - /dev/kmsg
      volumes:
        - /:/rootfs:ro
        - /var/run:/var/run:rw
        - /sys:/sys:ro
        - /var/lib/docker/:/var/lib/docker:ro
        - /dev/disk/:/dev/disk:ro
        - /etc/machine-id:/etc/machine-id:ro
  
    node-exporter:
      container_name: node-exporter
      image: prom/node-exporter:latest
      hostname: node-exporter
      restart: unless-stopped
      networks:
        - grafana
      expose:
        - 9100
      command:
        - --path.procfs=/host/proc
        - --path.sysfs=/host/sys
        - --path.rootfs=/host
        - --collector.filesystem.mount-points-exclude
        - ^/(sys|proc|dev|host|etc|rootfs/var/lib/docker/containers|rootfs/var/lib/docker/overlay2|rootfs/run/docker/netns|rootfs/var/lib/docker/aufs)($$|/)
      volumes:
        - /proc:/host/proc:ro
        - /sys:/host/sys:ro
        - /:/rootfs:ro
        - /:/host:ro,rslave
  
    prometheus:
      container_name: prometheus
      image: prom/prometheus:latest
      hostname: prometheus
      restart: unless-stopped
      command:
        - '--config.file=/etc/prometheus/prometheus.yml'
        - '--storage.tsdb.path=/prometheus'
        - '--storage.tsdb.retention.time=1y'
        # /!\ Uncomment the following line to set a size limit for the Prometheus database /!\
  #      - '--storage.tsdb.retention.size=10GB'
      networks:
        - grafana
      expose:
        - 9090
      volumes:
        # /!\ To be modified depending on your needs /!\
        - /home/rxchi1d/appdata/prometheus/data:/prometheus
        - /home/rxchi1d/appdata/prometheus/config/prometheus.yml:/etc/prometheus/prometheus.yml
      depends_on:
        - cadvisor
        - node-exporter
  
  networks:
    grafana:
      external: true

5. Configure Grafana

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1. Access Grafana (http://grafana-host:3000)

2. Add a data source:

   1. Navigate to Connections → Data sources and select Add new data source

   2. Choose Prometheus

   3. Set the Name to prometheus and the Connection URL to http://prometheus:9090. Click Save & test.

      

3. Import the dashboard:

   1. Go to Dashboards, click New → Import

      

   2. Upload the NPM-Monitor JSON

      Use dashboard ID 15120 to create the dashboard.

      

   3. Select the corresponding Prometheus data source:

      

Temperature Panel Shows “No data”

By default, node-exporter retrieves CPU temperature from thermal_zone* files in /sys/class/thermal. However, some systems lack the necessary sensors, resulting in no temperature data files in /sys/class/thermal. Consequently, CPU temperature panels in the dashboard will display no data.