CPU Temperature Monitoring with Docker

Overview

This guide explains how to build and run a Docker container that monitors CPU temperature. When the temperature of Package id 0 exceeds 70°C, the container will send an email alert using Gmail's SMTP server.

Prerequisites

1. Docker installed on your system.
2. A Gmail account with an app password created. You can create an app password here.

How to execute

1. Build and Run the Docker Image

Prepare Dockerfile and monitor.sh

Ensure you have the Dockerfile and monitor.sh files in your working directory.

Build the Docker Image

Open a terminal and navigate to the directory containing the Dockerfile and monitor.sh. Run the following command to build the Docker image:

docker build -t your-dockerhub-username/cpu-monitor:latest .

Replace your-dockerhub-username with your actual Docker Hub username.

Run the Docker Container

Execute the following command to run the Docker container. Replace the environment variables with your actual values:

docker run -d \
  --name cpu-monitor \
  -e SMTP_HOST=smtp.gmail.com \
  -e SMTP_PORT=587 \
  -e [email protected] \
  -e SMTP_PASS=your-app-password \
  -e [email protected] \
  your-dockerhub-username/cpu-monitor:latest

Environment variables:

• SMTP_HOST: SMTP server address (Gmail: smtp.gmail.com)
• SMTP_PORT: SMTP server port (Gmail: 587)
• SMTP_USER: Your Gmail address
• SMTP_PASS: Your Gmail app password
• EMAIL_TO: The recipient's email address for the alerts

Verify the Container

Check if the container is running correctly:

docker ps

You should see a container named cpu-monitor in the list of running containers.

Check the Logs

To verify that the script is running and check for any errors, view the container logs:

docker logs cpu-monitor

2. Pull and Run the Image from Docker Hub

Instead of building the image, you can directly pull it from Docker Hub.

Pull the Docker Image

Use the following command to pull the image from Docker Hub:

docker pull jjaegii/cpu-monitor:latest

Run the Docker Container

Execute the following command to run the Docker container:

docker run -d \
  --name cpu-monitor \
  -e SMTP_HOST=smtp.gmail.com \
  -e SMTP_PORT=587 \
  -e [email protected] \
  -e SMTP_PASS=your-app-password \
  -e [email protected] \
  jjaegii/cpu-monitor:latest

3. Deploy to Kubernetes

Use the deployment.yaml file to deploy to a Kubernetes cluster.

deployment.yaml File

apiVersion: apps/v1
kind: Deployment
metadata:
  name: cpu-monitor
  labels:
    app: cpu-monitor
spec:
  replicas: 1
  selector:
    matchLabels:
      app: cpu-monitor
  template:
    metadata:
      labels:
        app: cpu-monitor
    spec:
      containers:
      - name: cpu-monitor
        image: jjaegii/cpu-monitor:latest
        env:
        - name: SMTP_HOST
          value: "smtp.gmail.com"
        - name: SMTP_PORT
          value: "587"
        - name: SMTP_USER
          value: "[email protected]"
        - name: SMTP_PASS
          value: "your-app-password"
        - name: EMAIL_TO
          value: "[email protected]"

Deploy to Kubernetes

Use the following command to deploy to the Kubernetes cluster:

kubectl apply -f deployment.yaml

Additional Information

• Ensure that your Docker daemon has access to the sensors. Depending on your system configuration, you might need to run the container with elevated privileges.
• The monitoring script checks the temperature every 60 seconds. Adjust the sleep duration in the monitor.sh script if you need a different frequency.

Troubleshooting

• If you encounter authentication issues with Gmail, ensure that the app password is correct and that your Gmail account settings allow access from less secure apps if needed.
• Verify that the sensors command is available and provides the expected output on your host system. You might need to install lm-sensors on your host.