This repository contains a robust bash script (docker_engine_install.sh) designed to automate the installation of the official Docker Engine on Debian-based Linux distributions like Ubuntu, Debian, Linux Mint, etc.

It simplifies the process by handling:

• Uninstalling older or conflicting Docker packages (docker.io, podman-docker, etc.).
• Setting up Docker's official APT repository correctly.
• Installing the latest stable versions of Docker Engine, CLI, containerd, Docker Buildx plugin, and Docker Compose plugin.
• Performing essential post-installation steps like adding the current user to the docker group.
• Offering options to configure Docker's daemon.json with sensible defaults or a custom data directory.

• Idempotent Uninstallation: Checks for and removes known older/conflicting packages.
• Official Repository Setup: Correctly adds Docker's GPG key and APT repository source.
• Modular Repository Setup: Utilizes a dedicated helper script (docker_engine_repo.sh) for clear and focused APT repository management.
• Prerequisite Handling: Installs necessary dependencies like ca-certificates, curl, gnupg, lsb-release, and jq.
• Latest Stable Docker: Installs docker-ce, docker-ce-cli, containerd.io, docker-buildx-plugin, docker-compose-plugin.
• User Group Management: Automatically adds the user running the script (via sudo) to the docker group for passwordless Docker command execution (requires logout/login).
• Optional Default Configuration (-c): Creates/updates /etc/docker/daemon.json to set log rotation limits (json-file driver, 10m size, 3 files) and enable BuildKit. Merges settings safely if the file exists and is valid JSON.
• Optional Custom Data Root (-d <path>): Configures Docker to use a specified directory for storing images, containers, volumes, etc., by setting the data-root option in /etc/docker/daemon.json. Merges settings safely.
• Robust JSON Handling: Uses jq to safely create or modify the /etc/docker/daemon.json file.
• Safety Checks: Includes set -e, set -o pipefail, and requires root/sudo privileges to run.

• A Debian-based Linux distribution (e.g., Ubuntu 20.04+, Debian 10+, Linux Mint 20+, etc.).
• sudo privileges.
• An active internet connection to download packages and GPG keys.

• docker_engine_install.sh: The main installation and configuration script.
• docker_engine_repo.sh: Helper script called by docker_engine_install.sh to set up Docker's APT repository.

1. Download or Clone the Script:

   git clone https://github.com/phreck/Docker_Engine_Ubuntu.git
   cd Docker_Engine_Ubuntu

   Or download the docker_engine_install.sh file directly.

2. Make the Script Executable:

   chmod +x docker_engine_install.sh

3. Run the Script with sudo:

   • Standard Installation:

     sudo ./docker_engine_install.sh

   • Install and Configure Default daemon.json:

     sudo ./docker_engine_install.sh -c

   • Install and Configure Custom Data Root:

     # Make sure the parent directory (e.g., /mnt) exists and is suitable
     sudo ./docker_engine_install.sh -d /mnt/my-docker-data

     (The script configures Docker to use this path; the Docker daemon will attempt to create the final directory if it doesn't exist when it starts)

   • Install with Both Default Config and Custom Data Root:

     sudo ./docker_engine_install.sh -c -d /var/lib/docker-custom-directory

   • Display Help Message:

     ./docker_engine_install.sh -h

• -c: Create or update /etc/docker/daemon.json. If the file exists and is valid JSON, merges the default settings below. If the file doesn't exist or is invalid, it will be created/overwritten with these settings (plus any -d setting).
• -d <path>: Set a custom absolute path for Docker's data-root directory in /etc/docker/daemon.json. Merges the setting if the file exists and is valid JSON. Requires an absolute path (e.g., /opt/docker).
• -h: Display the help message and exit.

When the -c flag is used, the script aims to configure /etc/docker/daemon.json to include the following settings (merged with existing settings or the -d option):

{
  "log-driver": "json-file",
  "log-opts": {
    "max-size": "10m",
    "max-file": "3"
  },
  "features": {
    "buildkit": true
  }
}