Transitioning Docker from Rootful to Rootless (Offline Setup)

Here’s a diagram illustrating the process of setting up Docker in rootless mode on a machine without internet access:

Note:

• Sudo access is required on both the remote and local machines.
• Internet access is required on the local machine.

On Machine with Internet Access (Local Machine)

1. Download Required Packages

   Download the necessary packages on your source machine using the command:

   sudo dnf install --downloadonly --downloaddir=pkg_folder <pkg_name>

   Required Packages:

   • docker-ce-rootless-extras.rpm

   • uidmap.rpm

   • libslirp0.rpm

   • slirp4netns.rpm

   Note: For downloading .rpm packages without installing them, refer to this link.

2. Ship Packages to Remote Machine

   Use scp to transfer the .rpm packages from the local machine to the remote machine:

   scp ./packages/* <remote_user>@<remote_ip>:~/packages/

3. Install Dependencies on Target Machine

   Install all the dependency packages using:

   rpm -ivh ./package.rpm

   Note: For installing the packages, refer to the link provided.

4. Enable Rootless Docker

   Verify dockerd-rootless-setuptool.sh

   Check if dockerd-rootless-setuptool.sh is present in /usr/bin:

   ls /usr/bin/ | grep dockerd-rootless-setuptool.sh

   Note: If the script is not present, ensure that the docker-ce-rootless-extras package was installed correctly.

   Set Up Rootless Docker

   Run the installation command as a non-root user:

   /usr/bin/dockerd-rootless-setuptool.sh install

5. Verify Docker is Running Rootless

   Run the following to confirm Docker is operating in rootless mode:

   docker ps

Additional Commands for Downloading Packages

• Download Docker rootless extras package:

  sudo dnf install -y --download-only docker-ce-rootless-extras

• Download uidmap package:

  sudo dnf install -y --download-only uidmap

• Download slirp4netns package:

  sudo apt install -y --download-only slirp4netns

• Download libslirp0 package:

  sudo apt install -y --download-only libslirp0

The downloaded packages will be saved in the /var/cache/apt/archives directory.

Transfer Packages to Target Machine Using scp

scp /var/cache/apt/archives/docker-ce-rootless-extras_5%3a27.0.3-1~ubuntu.20.04~focal_amd64.deb [email protected]:~/
scp /var/cache/apt/archives/uidmap_1%3a4.8.1-1ubuntu5.20.04.5_amd64.deb [email protected]:~/
scp /var/cache/apt/archives/slirp4netns_0.4.3-1_amd64.deb [email protected]:~/
scp /var/cache/apt/archives/libslirp0_4.1.0-2ubuntu2.2_amd64.deb [email protected]:~/

Machine Without Internet Access (Target Machine)

1. Install Transferred Packages

   On the target machine, navigate to the directory where the packages were transferred and install them using dpkg:

   sudo dpkg -i docker-ce-rootless-extras_5%3a27.0.3-1~ubuntu.20.04~focal_amd64.deb
   sudo dpkg -i uidmap_1%3a4.8.1-1ubuntu5.20.04.5_amd64.deb
   sudo dpkg -i slirp4netns_0.4.3-1_amd64.deb
   sudo dpkg -i libslirp0_4.1.0-2ubuntu2.2_amd64.deb