Best way to install Docker on Vagrant

Introduction

Vagrant is a tool for building and managing development environments using virtualization software such as VirtualBox. It allows you to define and configure a development environment in a Vagrantfile and then spin up and tear down virtual machines quickly and easily.

By using Docker and Vagrant together, you can create a flexible and reproducible development environment that is easy to set up and maintain. This article discusses the best way to install Docker on Vagrant, including the prerequisites, installation steps, and verification.

Prerequisites for installing Docker on Vagrant

Before installing Docker on Vagrant, you must ensure you have the necessary software installed on your machine. Vagrant uses virtualization software such as VirtualBox to create virtual machines. You must install VirtualBox or another supported virtualization software to run Docker on Vagrant.

To install VirtualBox and vagrant on Linux, follow these steps −

• Install VirtualBox −

$ sudo apt-get install virtualbox

• Install Vagrant

$ sudo apt-get install vagrant

Installing Docker on Vagrant

Now that you have the necessary software installed, you can install Docker on Vagrant. There are two main options for installing Docker on Vagrant: using the Docker provisioner in a Vagrantfile or installing Docker manually on a Vagrant virtual machine.

Installing Docker using the Docker provisioner in a Vagrantfile

To use the Docker provisioner in a Vagrantfile, you need to add the following lines to your Vagrantfile −

config.vm.provision "docker" do |d|
  d.pull_images "redis:4"
  d.run "redis", args: "-p 6379:6379 --name redis -d redis:4"
end

This Vagrantfile does the following −

• Installs the Docker provisioner, which installs Docker on the virtual machine.

• Pulls the redis:4 image from Docker Hub.

• Runs the redis container, exposing port 6379 and giving it the name redis.

To start the virtual machine and run the Docker container, enter the following command −

$ vagrant up 

This will start the virtual machine and run the Docker container inside it.

Installing Docker manually on a Vagrant virtual machine

Alternatively, you can install Docker manually on a Vagrant virtual machine. To do this, you need to SSH into the virtual machine and follow the steps for installing Docker on the base operating system.

Here are the steps for installing Docker on an Ubuntu virtual machine −

• SSH into the virtual machine −

$ vagrant ssh 

• Update the package manager −

Vagrant-machine$ sudo apt-get update 

• Install Docker −

Vagrant-machine$ sudo apt-get install docker.io 

• Add your user to the docker group −

Vagrant-machine$ sudo usermod -aG docker $USER 

• Log out

Vagrant-machine$ exit 

Verifying the Docker installation on Vagrant

Once you have installed Docker on Vagrant, you can verify the installation by running a simple Docker container.

$ vagrant ssh 

Verify the installation −

$ docker --version

To run a simple Docker container, enter the following command −

$ docker run hello-world 

This command pulls the hello-world image from Docker Hub and runs it in a container. You should see output similar to this −

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

If you see this output, it means that Docker is installed and working correctly on Vagrant.

Troubleshooting common issues with the Docker installation on Vagrant

If you encounter issues with the Docker installation on Vagrant, here are some common causes and solutions −

• Make sure you have the necessary software installed −

Docker requires VirtualBox or another supported virtualization software to run on Vagrant. Ensure you have installed the necessary software and that it is up to date.

• Check the version of Vagrant −

Docker is supported on Vagrant 2.2.4 and later. Make sure you are using a compatible version of Vagrant.

• Check the version of the base operating system −

Docker is supported on Ubuntu 16.04 and later, CentOS 7 and later, and Debian 9 and later. Make sure you are using a compatible version of the base operating system.

• Check the version of Docker −

Docker is supported on Docker 17.03 and later. Make sure you are using a compatible version of Docker.

• Check the logs for errors −

You can check the logs for errors if you encounter issues with the Docker installation. Ubuntu and Debian's logs are located in /var/log/syslog. On CentOS, the logs are located in /var/log/messages.

• Check the firewall settings −

If you cannot access Docker from your host machine, it may be because the firewall is blocking access. You can check the firewall settings and add exceptions as necessary.

By following these steps, you should be able to troubleshoot common issues with the Docker installation on Vagrant. If you are still experiencing issues, you can check the Docker and Vagrant documentation for further guidance.

Conclusion

In this article, we have discussed the best way to install Docker on Vagrant. We have covered the prerequisites for installing Docker on Vagrant, including the necessary software and requirements. We have also discussed the two main options for installing Docker on Vagrant: using the Docker provisioner in a Vagrantfile or installing Docker manually on a Vagrant virtual machine. Finally, we have covered how to verify the Docker installation on Vagrant and troubleshoot common issues.