How to start docker on Raspberry Pi

In this increasingly rapid digital era, the use of embedded systems continues to increase, especially Raspberry Pi. The Raspberry Pi is an open source single-board computer primarily designed for education. But now, it is widely used in everything from small servers to Internet of Things (IoT) applications and home automation devices. Docker is a very popular container technology in recent years, making applications easier to deploy and manage. So, how to use Docker on Raspberry Pi? In this article, we will explain how to start Docker on the Raspberry Pi.

Step One: Install Docker

To use Docker on the Raspberry Pi, you first need to install it on the Raspberry Pi. Docker can be installed with the following command:

sudo apt-get install -y docker.io

This process may take some time and requires entering the sudo password.

After the installation is complete, you can run the following command to check whether Docker has been installed correctly:

sudo docker run hello-world

If everything is OK, the output should be similar to the following:

Hello from Docker.
This message shows that your installation appears to be working correctly.
...

Step 2 : Use Docker to quickly deploy applications

Once Docker is installed, we can use Docker to quickly deploy our applications.

Suppose we want to deploy a Node.js web application on the Raspberry Pi. We can use the following command to run the container:

sudo docker run -d -p 80:8080 node:8-alpine

This command does a lot of things. First it tells Docker to run the container in the background (-d option). It then uses the -p option to map the host's port 80 to the container's port 8080. Finally, it tells Docker to use the node:8-alpine image to create the container. This image is a lightweight Node.js image.

Now, we can access the Raspberry Pi’s IP address in a browser and see our Node.js application running.

Step 3: Use Docker Compose to manage multiple containers

If we need to manage many Docker containers, manually starting each container will become very tedious. At this time, we can use Docker Compose to simplify this process.

Docker Compose is a tool for defining and running multi-container Docker applications. We can use a yaml file to define all the required containers and then use the docker-compose command to start them.

First, install Docker Compose on the Raspberry Pi, you can use the following command:

sudo apt-get install -y docker-compose

Next, we create a file named docker-compose.yml and add our Node. js application is combined with a Redis container, as shown below:

version: '3'
services:
  node:
    container_name: my-node-app
    build: .
    ports:
      - "80:8080"
    depends_on:
      - redis
    environment:
      REDIS_HOST: redis
    restart: always
  redis:
    container_name: my-redis
    image: "redis:alpine"
    restart: always

This file defines two services: node and redis. The Node.js service is built using our application Dockerfile and maps the host's port 80 to the container's port 8080. The service also relies on the redis service and sets an environment variable called REDIS_HOST, which points to our redis container. The service is also configured to automatically restart after each container crash. The Redis service uses the official alpine image of Redis and is configured with automatic restart.

Finally, we can start the service using the following command in the directory containing the docker-compose.yml file:

sudo docker-compose up

This command will automatically build and start our service. We can access port 80 in the browser and see that our Node.js application is running and interacting with the Redis service.

Summary

Docker is an extremely popular container technology that can help us manage and deploy applications. On the Raspberry Pi, using Docker can quickly deploy applications, and using Docker Compose can help us simplify the process of managing multiple containers. Hopefully this article helped you better understand how to use Docker on the Raspberry Pi.

The above is the detailed content of How to start docker on Raspberry Pi. For more information, please follow other related articles on the PHP Chinese website!