/docker-snap

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Docker Snap

This repository contains the source for the docker snap package. The package provides a distribution of Docker Community Edition (CE) for Ubuntu Core 16 (and other snap-compatible) systems. It is built from an upstream Docker CE release tag with some patches to fit the snap format and is available on armhf, arm64, amd64, i386, and ppc64el architectures. The rest of this page describes installation, usage, and development.

NOTE: Docker's official documentation (https://docs.docker.com) does not yet discuss the docker snap package.

Installation

To install the latest stable release of Docker CE using snap:

$ sudo snap install docker

If you are using Ubuntu Core 16,

  • Connect the docker:home plug as it's not auto-connected by default:

    $ sudo snap connect docker:home :home
    

If you are using an alternative snap-compatible Linux distribution ("classic" in snap lingo), and would like to run docker as a normal user:

  • Create and join the docker group.

    $ sudo addgroup --system docker
    $ sudo adduser $USER docker
    $ newgrp docker
    
  • You will also need to disable and re-enable the docker snap if you added the group while it was running.

    $ sudo snap disable docker
    $ sudo snap enable docker
    

Usage

Docker should function normally, with the following caveats:

  • All files that docker needs access to should live within your $HOME folder.

    • If you are using Ubuntu Core 16, you'll need to work within a subfolder of $HOME that is readable by root. docker-archive#8
  • docker-compose is available as docker.compose due to snap naming restrictions.

  • Additional certificates used by the Docker daemon to authenticate with registries need to be located in /var/snap/docker/common/etc/certs.d instead of /etc/docker/certs.d.

Examples

Development

Developing the docker snap package is typically performed on a "classic" Ubuntu distribution. The instructions here are written for Ubuntu 16.04 "Xenial".

  • Install the snap tooling (requires snapd>2.21 and snapcraft>=2.26):

    $ sudo apt-get install snapd snapcraft
    $ sudo snap install core
    
  • Checkout this repository and build the docker snap package:

    $ git clone https://github.com/docker/docker-snap
    $ cd docker-snap
    $ sudo snapcraft
    
  • Install the newly-created snap package:

    $ sudo snap install --dangerous docker_[VER]_[ARCH].snap
    
  • Manually connect the relevant plugs and slots which are not auto-connected:

    $ sudo snap connect docker:privileged :docker-support
    $ sudo snap connect docker:support :docker-support
    $ sudo snap connect docker:firewall-control :firewall-control
    $ sudo snap connect docker:docker-cli docker:docker-daemon
    $ sudo snap disable docker
    $ sudo snap enable docker
    

    You should end up with output similar to:

    $ sudo snap interfaces docker
    Slot                  Plug
    :docker-support       docker:privileged,docker:support
    :firewall-control     docker
    :home                 docker
    :network              docker
    :network-bind         docker
    docker:docker-daemon  docker:docker-cli