RancherOS docker version updater.

switch-rancheros-docker.sh

#!/bin/bash
# RancherOS docker version updater.
# Author: @rajiteh
# License: BSD
#
# How to use:
#    You need to use a persistent console (tested on ubuntu).
#    Set up the script to be called at console initalization time.  
#
#    Example cloud-config.yml usage.
#
#      write_files:
#        - path: /etc/rc.local
#          permissions: "0755"
#          owner: root
#            content: |
#              #!/bin/bash
#              set -ex
#              DOCKER_VERSION=1.12.0
#              DOCKER_URL=https://experimental.docker.com/builds/Linux/x86_64/docker-1.12.0.tgz
#              SCRIPT_URL=https://gist.githubusercontent.com/rajiteh/ecf83e43c9c7f8443ff2f398e279c3f1/raw/9cba8e0024437a00ae1fd671a1cdebc809961415/switch-rancheros-docker.sh
#              _tmp=$(mktemp)
#              # Wait for networking to be available.
#              for i in {1..15}; do curl -fSso $_tmp $SCRIPT_URL && break || sleep 2; done
#              source $_tmp
#      rancher:
#        console: ubuntu
set -e

echo "DOCKER_VERSION  : ${DOCKER_VERSION}"
echo "DOCKER_URL      : ${DOCKER_URL}"

if [[ -z "${DOCKER_URL}" ]] || [[ -z "${DOCKER_VERSION}" ]]; then
 echo "DOCKER_URL or DOCKER_VERSION not set."
 return 1
fi


function get_docker_versions {
    c=$(/usr/bin/docker --version | sed -n 's/.*version \([^,]*\).*/\1/p')
    d=$(/usr/bin/dockerd --version | sed -n 's/.*version \([^,]*\).*/\1/p')
    echo "${c}|${d}"
}

_workdir=/tmp/docker-temp
_installed_versions="$(get_docker_versions)"
_expected_versions="${DOCKER_VERSION}|${DOCKER_VERSION}"

if [[ "${_installed_versions}" ==  "${_expected_versions}" ]]; then
    echo "Docker versions match."
    return 0
fi

echo "Detected docker client|server versions:  ${_installed_versions}"

mkdir -p "${_workdir}"
rm -rf "${_workdir}/dock*"
cd ${_workdir}

echo "Downloading: ${DOCKER_URL}"
curl -s "${DOCKER_URL}" -o docker.download

echo "Extracting."
tar xzf docker.download

cd docker/
_docker_bins=$(ls docker*)
_bin_paths=("/usr/local/bin" "/usr/bin")

echo "Copying and setting up symlinks."
for bin in ${_docker_bins[@]}; do
    sudo rm -f "/usr/local/bin/${bin}-${DOCKER_VERSION}"
    sudo cp "${bin}" "/usr/local/bin/${bin}-${DOCKER_VERSION}"
    
    for bin_path in ${_bin_paths[@]}; do
        sudo rm -f "${bin_path}/${bin}" 
        sudo ln -s "/usr/local/bin/${bin}-${DOCKER_VERSION}" "${bin_path}/${bin}"   
    done
    echo "Processed : ${bin}"
done

echo "New docker client|server versions:  $(get_docker_versions)"
echo "Restarting.."

sleep 2
sudo reboot