# Install Docker ## Ubuntu ### Prerequisites #### OS requirements To install Docker Engine, you need the 64-bit version of one of these Ubuntu versions: * Ubuntu Kinetic 22.10 * Ubuntu Jammy 22.04 (LTS) * Ubuntu Focal 20.04 (LTS) * Ubuntu Bionic 18.04 (LTS) Docker Engine is compatible with `x86_64` (or `amd64`), `armhf`, `arm64`, and `s390x` architectures. #### Uninstall old versions Older versions of Docker went by the names of `docker`, `docker.io`, or `docker-engine`. Uninstall any such older versions before attempting to install a new version: ``` $ sudo apt-get remove docker docker-engine docker.io containerd runc ``` It’s OK if `apt-get` reports that none of these packages are installed. Images, containers, volumes, and networks stored in `/var/lib/docker/` aren’t automatically removed when you uninstall Docker. If you want to start with a clean installation, and prefer to clean up any existing data, refer to the [uninstall Docker Engine](https://docs.docker.com/engine/install/ubuntu/#uninstall-docker-engine) section. ### Installation methods You can install Docker Engine in different ways, depending on your needs: * Docker Engine comes bundled with [Docker Desktop for Linux](https://docs.docker.com/desktop/install/linux-install/). This is the easiest and quickest way to get started. * You can also set up and install Docker Engine from [Docker’s `apt` repository](https://docs.docker.com/engine/install/ubuntu/#install-using-the-repository). * [Install it manually](https://docs.docker.com/engine/install/ubuntu/#install-from-a-package) and manage upgrades manually. * Using a [convenience scripts](https://docs.docker.com/engine/install/ubuntu/#install-using-the-convenience-script). Only recommended for testing and development environments. #### Install using the repository Before you install Docker Engine for the first time on a new host machine, you need to set up the Docker repository. Afterward, you can install and update Docker from the repository. **Set up the repository** 1. Update the `apt` package index and install packages to allow `apt` to use a repository over HTTPS: ```docker $ sudo apt-get update $ sudo apt-get install \ ca-certificates \ curl \ gnupg \ lsb-release ``` 2. Add Docker’s official GPG key: ```docker $ sudo mkdir -m 0755 -p /etc/apt/keyrings $ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo gpg --dearmor -o /etc/apt/keyrings/docker.gpg ``` 3. Use the following command to set up the repository: ```docker $ echo \ "deb [arch=$(dpkg --print-architecture) signed-by=/etc/apt/keyrings/docker.gpg] https://download.docker.com/linux/ubuntu \ $(lsb_release -cs) stable" | sudo tee /etc/apt/sources.list.d/docker.list > /dev/null ``` #### **Install Docker Engine** 1. Update the `apt` package index: ``` $ sudo apt-get update ``` **Receiving a GPG error when running** `apt-get update`**?** Your default [umask](https://en.wikipedia.org/wiki/Umask) may be incorrectly configured, preventing detection of the repository public key file. Try granting read permission for the Docker public key file before updating the package index: ``` $ sudo chmod a+r /etc/apt/keyrings/docker.gpg $ sudo apt-get update ``` 2. Install Docker Engine, containerd, and Docker Compose. 1. To install the **latest version**, run: ```docker $ sudo apt-get install docker-ce docker-ce-cli containerd.io docker-buildx-plugin docker-compose-plugin ``` 2. To install a **specific version** of Docker Engine, start by list the available versions in the repository: ``` # List the available versions: $ apt-cache madison docker-ce | awk '{ print $3 }' 5:20.10.16~3-0~ubuntu-jammy 5:20.10.15~3-0~ubuntu-jammy 5:20.10.14~3-0~ubuntu-jammy 5:20.10.13~3-0~ubuntu-jammy ``` Select the desired version and install: ``` $ VERSION_STRING=5:20.10.13~3-0~ubuntu-jammy $ sudo apt-get install docker-ce=$VERSION_STRING docker-ce-cli=$VERSION_STRING containerd.io docker-buildx-plugin docker-compose-plugin ``` 3. Verify that the Docker Engine installation is successful by running the `hello-world` image: ``` $ sudo docker run hello-world ``` This command downloads a test image and runs it in a container. When the container runs, it prints a confirmation message and exits. You have now successfully installed and started Docker Engine. The `docker` user group exists but contains no users, which is why you’re required to use `sudo` to run Docker commands. Continue to [Linux post-install](https://docs.docker.com/engine/install/linux-postinstall/) to allow non-privileged users to run Docker commands and for other optional configuration steps. **Upgrade Docker Engine** To upgrade Docker Engine, follow the [installation instructions](https://docs.docker.com/engine/install/ubuntu/#install-docker-engine), choosing the new version you want to install. #### Install from a package If you can’t use Docker’s `apt` repository to install Docker Engine, you can download the `deb` file for your release and install it manually. You need to download a new file each time you want to upgrade Docker Engine. 1. Go to [`https://download.docker.com/linux/ubuntu/dists/`](https://download.docker.com/linux/ubuntu/dists/). 2. Select your Ubuntu version in the list. 3. Go to `pool/stable/` and select the applicable architecture (`amd64`, `armhf`, `arm64`, or `s390x`). 4. Download the following `deb` files for the Docker Engine, CLI, containerd, and Docker Compose packages: * `containerd.io__.deb` * `docker-ce__.deb` * `docker-ce-cli__.deb` * `docker-buildx-plugin__.deb` * `docker-compose-plugin__.deb` 5. Install the `.deb` packages. Update the paths in the following example to where you downloaded the Docker packages. ``` $ sudo dpkg -i ./containerd.io__.deb \ ./docker-ce__.deb \ ./docker-ce-cli__.deb \ ./docker-buildx-plugin__.deb \ ./docker-compose-plugin__.deb ``` The Docker daemon starts automatically. 6. Verify that the Docker Engine installation is successful by running the `hello-world` image: ``` $ sudo service docker start $ sudo docker run hello-world ``` This command downloads a test image and runs it in a container. When the container runs, it prints a confirmation message and exits. You have now successfully installed and started Docker Engine. The `docker` user group exists but contains no users, which is why you’re required to use `sudo` to run Docker commands. Continue to [Linux post-install](https://docs.docker.com/engine/install/linux-postinstall/) to allow non-privileged users to run Docker commands and for other optional configuration steps. **Upgrade Docker Engine** To upgrade Docker Engine, download the newer package file and repeat the [installation procedure](https://docs.docker.com/engine/install/ubuntu/#install-from-a-package), pointing to the new file. #### Install using the convenience script Docker provides a convenience script at to install Docker into development environments non-interactively. The convenience script isn’t recommended for production environments, but it’s useful for creating a provisioning script tailored to your needs. Also refer to the [install using the repository](https://docs.docker.com/engine/install/ubuntu/#install-using-the-repository) steps to learn about installation steps to install using the package repository. The source code for the script is open source, and can be found in the [`docker-install` repository on GitHub](https://github.com/docker/docker-install). {% hint style="info" %} Tip: preview script steps before running You can run the script with the `--dry-run` option to learn what steps the script will run when invoked: ```docker $ curl -fsSL https://get.docker.com -o get-docker.sh $ sudo sh ./get-docker.sh --dry-run ``` {% endhint %} This example downloads the script from and runs it to install the latest stable release of Docker on Linux: ``` $ curl -fsSL https://get.docker.com -o get-docker.sh $ sudo sh get-docker.sh Executing docker install script, commit: 7cae5f8b0decc17d6571f9f52eb840fbc13b2737 <...> ``` You have now successfully installed and started Docker Engine. The `docker` service starts automatically on Debian based distributions. On `RPM` based distributions, such as CentOS, Fedora, RHEL or SLES, you need to start it manually using the appropriate `systemctl` or `service` command. As the message indicates, non-root users can’t run Docker commands by default. {% hint style="info" %} **Use Docker as a non-privileged user, or install in rootless mode?** The installation script requires `root` or `sudo` privileges to install and use Docker. If you want to grant non-root users access to Docker, refer to the [post-installation steps for Linux](https://docs.docker.com/engine/install/linux-postinstall/#manage-docker-as-a-non-root-user). You can also install Docker without `root` privileges, or configured to run in rootless mode. For instructions on running Docker in rootless mode, refer to [run the Docker daemon as a non-root user (rootless mode)](https://docs.docker.com/engine/security/rootless/). {% endhint %} **Install pre-releases** Docker also provides a convenience script at to install pre-releases of Docker on Linux. This script is equal to the script at `get.docker.com`, but configures your package manager to use the test channel of the Docker package repository. The test channel includes both stable and pre-releases (beta versions, release-candidates) of Docker. Use this script to get early access to new releases, and to evaluate them in a testing environment before they’re released as stable. To install the latest version of Docker on Linux from the test channel, run: ``` $ curl -fsSL https://test.docker.com -o test-docker.sh $ sudo sh test-docker.sh ``` **Upgrade Docker after using the convenience script** If you installed Docker using the convenience script, you should upgrade Docker using your package manager directly. There’s no advantage to re-running the convenience script. Re-running it can cause issues if it attempts to re-install repositories which already exist on the host machine. ## Reference Links * --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://dojo.lkmx.io/ingles/docker/install-docker.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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