Guides - Deploy Docker through the Linode Marketplace

Docker is a tool that enables you to create, deploy, and manage containers. Each container is a lightweight stand-alone package that containing the code, libraries, runtime, system settings, and dependencies that are required to run an application. Every container is deployed with its own CPU, memory, block I/O, and network resources, without having to depend upon an individual kernel and operating system. While it may be easiest to compare Docker to virtual machines, they differ in the way they share or dedicate resources.

Deploying a Marketplace App

The Linode Marketplace allows you to easily deploy software on a Compute Instance using the Cloud Manager. See Get Started with Marketplace Apps for complete steps.

1. Log in to the Cloud Manager and select the Marketplace link from the left navigation menu. This displays the Linode Create page with the Marketplace tab pre-selected.

2. Under the Select App section, select the app you would like to deploy.

3. Complete the form by following the steps and advice within the Creating a Compute Instance guide. Depending on the Marketplace App you selected, there may be additional configuration options available. See the Configuration Options section below for compatible distributions, recommended plans, and any additional configuration options available for this Marketplace App.

4. Click the Create Linode button. Once the Compute Instance has been provisioned and has fully powered on, wait for the software installation to complete. If the instance is powered off or restarted before this time, the software installation will likely fail.

To verify that the app has been fully installed, see Get Started with Marketplace Apps > Verify Installation. Once installed, follow the instructions within the Getting Started After Deployment section to access the application and start using it.

Configuration Options

• Supported distributions: Ubuntu 22.04 LTS
• Recommended minimum plan: All plan types and sizes can be used.

Docker Options

Limited Sudo User

You need to fill out the following fields to automatically create a limited sudo user, with a strong generated password for your new Compute Instance. This account will be assigned to the sudo group, which provides elevated permissions when running commands with the sudo prefix.

• Limited sudo user: Enter your preferred username for the limited user. No Capital Letters, Spaces, or Special Characters.

  Locating The Generated Sudo Password

  A password is generated for the limited user and stored in a .credentials file in their home directory, along with application specific passwords. This can be viewed by running: cat /home/$USERNAME/.credentials

  For best results, add an account SSH key for the Cloud Manager user that is deploying the instance, and select that user as an authorized_user in the API or by selecting that option in the Cloud Manager. Their SSH pubkey will be assigned to both root and the limited user.

• Disable root access over SSH: To block the root user from logging in over SSH, select Yes. You can still switch to the root user once logged in, and you can also log in as root through Lish.

  Accessing The Instance Without SSH

  If you disable root access for your deployment and do not provide a valid Account SSH Key assigned to the authorized_user, you will need to login as the root user via the Lish console and run cat /home/$USERNAME/.credentials to view the generated password for the limited user.

Custom Domain (Optional)

If you wish to automatically configure a custom domain, you first need to configure your domain to use Linode’s name servers. This is typically accomplished directly through your registrar. See Use Linode’s Name Servers with Your Domain. Once that is finished, you can fill out the following fields for the Marketplace App:

• Linode API Token: If you wish to use the Linode’s DNS Manager to manage DNS records for your custom domain, create a Linode API Personal Access Token on your account with Read/Write access to Domains. If this is provided along with the subdomain and domain fields (outlined below), the installation attempts to create DNS records via the Linode API. See Get an API Access Token. If you do not provide this field, you need to manually configure your DNS records through your DNS provider and point them to the IP address of the new instance.

• Subdomain: The subdomain you wish to use, such as www for www.example.com.

• Domain: The domain name you wish to use, such as example.com.

• Email address for SOA Record: This should be the email address of your server administrator.

Getting Started after Deployment

Docker is now installed and ready to use. The following steps provide a sample application to get you started with an easy example to demonstrate some basic Docker functionality. It is not necessary for Docker set-up.

Deploy a Sample Application

After Docker has finished installing, you can access Docker from your terminal and deploy a sample application or any application that you intend on running.

1. Log in to your Compute Instance via SSH or Lish using the limited user account you may have created during deployment. If you do not yet have one, login as the root user and create a limited user account.

2. Locate the application or sample application you wish to deploy.

   • Docker Hub: Find official docker images, such as one for NGINX, Node.js, or the Hello World test image. Each image should be accompanied with documentation on how to use it.
   • Docker Samples: Docker’s documentation has a list of sample applications with full instructions for running each sample. This includes a WordPress sample, as well as ASP.NET Core and Django.
   • Docker Samples Repository: Additional sample applications you can run.

3. Learn how to use Docker by running through the Docker for Beginners lab or by reading the documentation below:

   • An Introduction to Docker
   • How to Deploy an nginx Container with Docker on Linode
   • Docker Commands Quick Reference Cheat Sheet
   • How to Use Docker Files
   • How to Use Docker Compose
   • How to Connect Docker Containers
   • How to Create a Docker Swarm Manager and Nodes on a Linode
   • Create and Deploy a Docker Container Image to a Kubernetes Cluster
   • Manage a Docker Cluster with Kubernetes

More Information

You may wish to consult the following resources for additional information on this topic. While these are provided in the hope that they will be useful, please note that we cannot vouch for the accuracy or timeliness of externally hosted materials.

• Docker Commands Cheat Sheet
• Docker Documentation
• Play with Docker
• Docker Hub