hack/install.sh - third_party/github.com/moby/moby - Git at Google

 #!/bin/sh
 set -e
 #
 # This script is meant for quick & easy install via:
 #   'curl -sSL https://get.docker.com/ | sh'
 # or:
 #   'wget -qO- https://get.docker.com/ | sh'
 #
 # For test builds (ie. release candidates):
 #   'curl -sSL https://test.docker.com/ | sh'
 # or:
 #   'wget -qO- https://test.docker.com/ | sh'
 #
 # For experimental builds:
 #   'curl -sSL https://experimental.docker.com/ | sh'
 # or:
 #   'wget -qO- https://experimental.docker.com/ | sh'
 #
 # Docker Maintainers:
 #   To update this script on https://get.docker.com,
 #   use hack/release.sh during a normal release,
 #   or the following one-liner for script hotfixes:
 #     s3cmd put --acl-public -P hack/install.sh s3://get.docker.com/index
 #

 url='https://get.docker.com/'

 command_exists() {
 	command -v "$@" > /dev/null 2>&1
 }

 echo_docker_as_nonroot() {
 	if command_exists docker && [ -e /var/run/docker.sock ]; then
 		(
 			set -x
 			$sh_c 'docker version'
 		) || true
 	fi
 	your_user=your-user
 	[ "$user" != 'root' ] && your_user="$user"
 	# intentionally mixed spaces and tabs here -- tabs are stripped by "<<-EOF", spaces are kept in the output
 	cat <<-EOF

 	If you would like to use Docker as a non-root user, you should now consider
 	adding your user to the "docker" group with something like:

 	  sudo usermod -aG docker $your_user

 	Remember that you will have to log out and back in for this to take effect!

 	EOF
 }

 # Check if this is a forked Linux distro
 check_forked() {
 	# Check for lsb_release command existence, it usually exists in forked distros
 	if command_exists lsb_release; then
 		# Check if the `-u` option is supported
 		set +e
 		lsb_release -a -u > /dev/null 2>&1
 		lsb_release_exit_code=$?
 		set -e

 		# Check if the command has exited successfully, it means we're in a forked distro
 		if [ "$lsb_release_exit_code" = "0" ]; then
 			# Print info about current distro
 			cat <<-EOF
 			You're using '$lsb_dist' version '$dist_version'.
 			EOF

 			# Get the upstream release info
 			lsb_dist=$(lsb_release -a -u 2>&1 | tr '[:upper:]' '[:lower:]' | grep -E 'id' | cut -d ':' -f 2 | tr -d '[[:space:]]')
 			dist_version=$(lsb_release -a -u 2>&1 | tr '[:upper:]' '[:lower:]' | grep -E 'codename' | cut -d ':' -f 2 | tr -d '[[:space:]]')

 			# Print info about upstream distro
 			cat <<-EOF
 			Upstream release is '$lsb_dist' version '$dist_version'.
 			EOF
 		fi
 	fi
 }

 do_install() {
 	case "$(uname -m)" in
 		*64)
 			;;
 		*)
 			cat >&2 <<-'EOF'
 			Error: you are not using a 64bit platform.
 			Docker currently only supports 64bit platforms.
 			EOF
 			exit 1
 			;;
 	esac

 	if command_exists docker; then
 		cat >&2 <<-'EOF'
 			Warning: the "docker" command appears to already exist on this system.

 			If you already have Docker installed, this script can cause trouble, which is
 			why we're displaying this warning and provide the opportunity to cancel the
 			installation.

 			If you installed the current Docker package using this script and are using it
 			again to update Docker, you can safely ignore this message.

 			You may press Ctrl+C now to abort this script.
 		EOF
 		( set -x; sleep 20 )
 	fi

 	user="$(id -un 2>/dev/null || true)"

 	sh_c='sh -c'
 	if [ "$user" != 'root' ]; then
 		if command_exists sudo; then
 			sh_c='sudo -E sh -c'
 		elif command_exists su; then
 			sh_c='su -c'
 		else
 			cat >&2 <<-'EOF'
 			Error: this installer needs the ability to run commands as root.
 			We are unable to find either "sudo" or "su" available to make this happen.
 			EOF
 			exit 1
 		fi
 	fi

 	curl=''
 	if command_exists curl; then
 		curl='curl -sSL'
 	elif command_exists wget; then
 		curl='wget -qO-'
 	elif command_exists busybox && busybox --list-modules | grep -q wget; then
 		curl='busybox wget -qO-'
 	fi

 	# check to see which repo they are trying to install from
 	repo='main'
 	if [ "https://test.docker.com/" = "$url" ]; then
 		repo='testing'
 	elif [ "https://experimental.docker.com/" = "$url" ]; then
 		repo='experimental'
 	fi

 	# perform some very rudimentary platform detection
 	lsb_dist=''
 	dist_version=''
 	if command_exists lsb_release; then
 		lsb_dist="$(lsb_release -si)"
 	fi
 	if [ -z "$lsb_dist" ] && [ -r /etc/lsb-release ]; then
 		lsb_dist="$(. /etc/lsb-release && echo "$DISTRIB_ID")"
 	fi
 	if [ -z "$lsb_dist" ] && [ -r /etc/debian_version ]; then
 		lsb_dist='debian'
 	fi
 	if [ -z "$lsb_dist" ] && [ -r /etc/fedora-release ]; then
 		lsb_dist='fedora'
 	fi
 	if [ -z "$lsb_dist" ] && [ -r /etc/oracle-release ]; then
 		lsb_dist='oracleserver'
 	fi
 	if [ -z "$lsb_dist" ]; then
 		if [ -r /etc/centos-release ] || [ -r /etc/redhat-release ]; then
 			lsb_dist='centos'
 		fi
 	fi
 	if [ -z "$lsb_dist" ] && [ -r /etc/os-release ]; then
 		lsb_dist="$(. /etc/os-release && echo "$ID")"
 	fi

 	lsb_dist="$(echo "$lsb_dist" | tr '[:upper:]' '[:lower:]')"

 	case "$lsb_dist" in

 		ubuntu)
 			if command_exists lsb_release; then
 				dist_version="$(lsb_release --codename | cut -f2)"
 			fi
 			if [ -z "$dist_version" ] && [ -r /etc/lsb-release ]; then
 				dist_version="$(. /etc/lsb-release && echo "$DISTRIB_CODENAME")"
 			fi
 		;;

 		debian)
 			dist_version="$(cat /etc/debian_version | sed 's/\/.*//' | sed 's/\..*//')"
 			case "$dist_version" in
 				8)
 					dist_version="jessie"
 				;;
 				7)
 					dist_version="wheezy"
 				;;
 			esac
 		;;

 		oracleserver)
 			# need to switch lsb_dist to match yum repo URL
 			lsb_dist="oraclelinux"
 			dist_version="$(rpm -q --whatprovides redhat-release --queryformat "%{VERSION}\n" | sed 's/\/.*//' | sed 's/\..*//' | sed 's/Server*//')"
 		;;

 		fedora|centos)
 			dist_version="$(rpm -q --whatprovides redhat-release --queryformat "%{VERSION}\n" | sed 's/\/.*//' | sed 's/\..*//' | sed 's/Server*//')"
 		;;

 		*)
 			if command_exists lsb_release; then
 				dist_version="$(lsb_release --codename | cut -f2)"
 			fi
 			if [ -z "$dist_version" ] && [ -r /etc/os-release ]; then
 				dist_version="$(. /etc/os-release && echo "$VERSION_ID")"
 			fi
 		;;


 	esac

 	# Check if this is a forked Linux distro
 	check_forked

 	# Run setup for each distro accordingly
 	case "$lsb_dist" in
 		amzn)
 			(
 			set -x
 			$sh_c 'sleep 3; yum -y -q install docker'
 			)
 			echo_docker_as_nonroot
 			exit 0
 			;;

 		'opensuse project'|opensuse|'suse linux'|sle[sd])
 			(
 				set -x
 				$sh_c 'sleep 3; zypper -n install docker'
 			)
 			echo_docker_as_nonroot
 			exit 0
 			;;

 		ubuntu|debian)
 			export DEBIAN_FRONTEND=noninteractive

 			did_apt_get_update=
 			apt_get_update() {
 				if [ -z "$did_apt_get_update" ]; then
 					( set -x; $sh_c 'sleep 3; apt-get update' )
 					did_apt_get_update=1
 				fi
 			}

 			# aufs is preferred over devicemapper; try to ensure the driver is available.
 			if ! grep -q aufs /proc/filesystems && ! $sh_c 'modprobe aufs'; then
 				if uname -r | grep -q -- '-generic' && dpkg -l 'linux-image-*-generic' | grep -q '^ii' 2>/dev/null; then
 					kern_extras="linux-image-extra-$(uname -r) linux-image-extra-virtual"

 					apt_get_update
 					( set -x; $sh_c 'sleep 3; apt-get install -y -q '"$kern_extras" ) || true

 					if ! grep -q aufs /proc/filesystems && ! $sh_c 'modprobe aufs'; then
 						echo >&2 'Warning: tried to install '"$kern_extras"' (for AUFS)'
 						echo >&2 ' but we still have no AUFS.  Docker may not work. Proceeding anyways!'
 						( set -x; sleep 10 )
 					fi
 				else
 					echo >&2 'Warning: current kernel is not supported by the linux-image-extra-virtual'
 					echo >&2 ' package.  We have no AUFS support.  Consider installing the packages'
 					echo >&2 ' linux-image-virtual kernel and linux-image-extra-virtual for AUFS support.'
 					( set -x; sleep 10 )
 				fi
 			fi

 			# install apparmor utils if they're missing and apparmor is enabled in the kernel
 			# otherwise Docker will fail to start
 			if [ "$(cat /sys/module/apparmor/parameters/enabled 2>/dev/null)" = 'Y' ]; then
 				if command -v apparmor_parser >/dev/null 2>&1; then
 					echo 'apparmor is enabled in the kernel and apparmor utils were already installed'
 				else
 					echo 'apparmor is enabled in the kernel, but apparmor_parser missing'
 					apt_get_update
 					( set -x; $sh_c 'sleep 3; apt-get install -y -q apparmor' )
 				fi
 			fi

 			if [ ! -e /usr/lib/apt/methods/https ]; then
 				apt_get_update
 				( set -x; $sh_c 'sleep 3; apt-get install -y -q apt-transport-https ca-certificates' )
 			fi
 			if [ -z "$curl" ]; then
 				apt_get_update
 				( set -x; $sh_c 'sleep 3; apt-get install -y -q curl ca-certificates' )
 				curl='curl -sSL'
 			fi
 			(
 			set -x
 			$sh_c "apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D"
 			$sh_c "mkdir -p /etc/apt/sources.list.d"
 			$sh_c "echo deb https://apt.dockerproject.org/repo ${lsb_dist}-${dist_version} ${repo} > /etc/apt/sources.list.d/docker.list"
 			$sh_c 'sleep 3; apt-get update; apt-get install -y -q docker-engine'
 			)
 			echo_docker_as_nonroot
 			exit 0
 			;;

 		fedora|centos|oraclelinux)
 			$sh_c "cat >/etc/yum.repos.d/docker-${repo}.repo" <<-EOF
 			[docker-${repo}-repo]
 			name=Docker ${repo} Repository
 			baseurl=https://yum.dockerproject.org/repo/${repo}/${lsb_dist}/${dist_version}
 			enabled=1
 			gpgcheck=1
 			gpgkey=https://yum.dockerproject.org/gpg
 			EOF
 			if [ "$lsb_dist" = "fedora" ] && [ "$dist_version" -ge "22" ]; then
 				(
 					set -x
 					$sh_c 'sleep 3; dnf -y -q install docker-engine'
 				)
 			else
 				(
 					set -x
 					$sh_c 'sleep 3; yum -y -q install docker-engine'
 				)
 			fi
 			echo_docker_as_nonroot
 			exit 0
 			;;
 		gentoo)
 			if [ "$url" = "https://test.docker.com/" ]; then
 				# intentionally mixed spaces and tabs here -- tabs are stripped by "<<-'EOF'", spaces are kept in the output
 				cat >&2 <<-'EOF'

 				  You appear to be trying to install the latest nightly build in Gentoo.'
 				  The portage tree should contain the latest stable release of Docker, but'
 				  if you want something more recent, you can always use the live ebuild'
 				  provided in the "docker" overlay available via layman.  For more'
 				  instructions, please see the following URL:'

 				    https://github.com/tianon/docker-overlay#using-this-overlay'

 				  After adding the "docker" overlay, you should be able to:'

 				    emerge -av =app-emulation/docker-9999'

 				EOF
 				exit 1
 			fi

 			(
 				set -x
 				$sh_c 'sleep 3; emerge app-emulation/docker'
 			)
 			exit 0
 			;;
 	esac

 	# intentionally mixed spaces and tabs here -- tabs are stripped by "<<-'EOF'", spaces are kept in the output
 	cat >&2 <<-'EOF'

 	  Either your platform is not easily detectable, is not supported by this
 	  installer script (yet - PRs welcome! [hack/install.sh]), or does not yet have
 	  a package for Docker.  Please visit the following URL for more detailed
 	  installation instructions:

 	    https://docs.docker.com/en/latest/installation/

 	EOF
 	exit 1
 }

 # wrapped up in a function so that we have some protection against only getting
 # half the file during "curl | sh"
 do_install
	#!/bin/sh
	set -e
	#
	# This script is meant for quick & easy install via:
	# 'curl -sSL https://get.docker.com/ \| sh'
	# or:
	# 'wget -qO- https://get.docker.com/ \| sh'
	#
	# For test builds (ie. release candidates):
	# 'curl -sSL https://test.docker.com/ \| sh'
	# or:
	# 'wget -qO- https://test.docker.com/ \| sh'
	#
	# For experimental builds:
	# 'curl -sSL https://experimental.docker.com/ \| sh'
	# or:
	# 'wget -qO- https://experimental.docker.com/ \| sh'
	#
	# Docker Maintainers:
	# To update this script on https://get.docker.com,
	# use hack/release.sh during a normal release,
	# or the following one-liner for script hotfixes:
	# s3cmd put --acl-public -P hack/install.sh s3://get.docker.com/index
	#

	url='https://get.docker.com/'

	command_exists() {
	command -v "$@" > /dev/null 2>&1
	}

	echo_docker_as_nonroot() {
	if command_exists docker && [ -e /var/run/docker.sock ]; then
	(
	set -x
	$sh_c 'docker version'
	) \|\| true
	fi
	your_user=your-user
	[ "$user" != 'root' ] && your_user="$user"
	# intentionally mixed spaces and tabs here -- tabs are stripped by "<<-EOF", spaces are kept in the output
	cat <<-EOF

	If you would like to use Docker as a non-root user, you should now consider
	adding your user to the "docker" group with something like:

	sudo usermod -aG docker $your_user

	Remember that you will have to log out and back in for this to take effect!

	EOF
	}

	# Check if this is a forked Linux distro
	check_forked() {
	# Check for lsb_release command existence, it usually exists in forked distros
	if command_exists lsb_release; then
	# Check if the `-u` option is supported
	set +e
	lsb_release -a -u > /dev/null 2>&1
	lsb_release_exit_code=$?
	set -e

	# Check if the command has exited successfully, it means we're in a forked distro
	if [ "$lsb_release_exit_code" = "0" ]; then
	# Print info about current distro
	cat <<-EOF
	You're using '$lsb_dist' version '$dist_version'.
	EOF

	# Get the upstream release info
	lsb_dist=$(lsb_release -a -u 2>&1 \| tr '[:upper:]' '[:lower:]' \| grep -E 'id' \| cut -d ':' -f 2 \| tr -d '[[:space:]]')
	dist_version=$(lsb_release -a -u 2>&1 \| tr '[:upper:]' '[:lower:]' \| grep -E 'codename' \| cut -d ':' -f 2 \| tr -d '[[:space:]]')

	# Print info about upstream distro
	cat <<-EOF
	Upstream release is '$lsb_dist' version '$dist_version'.
	EOF
	fi
	fi
	}

	do_install() {
	case "$(uname -m)" in
	*64)
	;;
	*)
	cat >&2 <<-'EOF'
	Error: you are not using a 64bit platform.
	Docker currently only supports 64bit platforms.
	EOF
	exit 1
	;;
	esac

	if command_exists docker; then
	cat >&2 <<-'EOF'
	Warning: the "docker" command appears to already exist on this system.

	If you already have Docker installed, this script can cause trouble, which is
	why we're displaying this warning and provide the opportunity to cancel the
	installation.

	If you installed the current Docker package using this script and are using it
	again to update Docker, you can safely ignore this message.

	You may press Ctrl+C now to abort this script.
	EOF
	( set -x; sleep 20 )
	fi

	user="$(id -un 2>/dev/null \|\| true)"

	sh_c='sh -c'
	if [ "$user" != 'root' ]; then
	if command_exists sudo; then
	sh_c='sudo -E sh -c'
	elif command_exists su; then
	sh_c='su -c'
	else
	cat >&2 <<-'EOF'
	Error: this installer needs the ability to run commands as root.
	We are unable to find either "sudo" or "su" available to make this happen.
	EOF
	exit 1
	fi
	fi

	curl=''
	if command_exists curl; then
	curl='curl -sSL'
	elif command_exists wget; then
	curl='wget -qO-'
	elif command_exists busybox && busybox --list-modules \| grep -q wget; then
	curl='busybox wget -qO-'
	fi

	# check to see which repo they are trying to install from
	repo='main'
	if [ "https://test.docker.com/" = "$url" ]; then
	repo='testing'
	elif [ "https://experimental.docker.com/" = "$url" ]; then
	repo='experimental'
	fi

	# perform some very rudimentary platform detection
	lsb_dist=''
	dist_version=''
	if command_exists lsb_release; then
	lsb_dist="$(lsb_release -si)"
	fi
	if [ -z "$lsb_dist" ] && [ -r /etc/lsb-release ]; then
	lsb_dist="$(. /etc/lsb-release && echo "$DISTRIB_ID")"
	fi
	if [ -z "$lsb_dist" ] && [ -r /etc/debian_version ]; then
	lsb_dist='debian'
	fi
	if [ -z "$lsb_dist" ] && [ -r /etc/fedora-release ]; then
	lsb_dist='fedora'
	fi
	if [ -z "$lsb_dist" ] && [ -r /etc/oracle-release ]; then
	lsb_dist='oracleserver'
	fi
	if [ -z "$lsb_dist" ]; then
	if [ -r /etc/centos-release ] \|\| [ -r /etc/redhat-release ]; then
	lsb_dist='centos'
	fi
	fi
	if [ -z "$lsb_dist" ] && [ -r /etc/os-release ]; then
	lsb_dist="$(. /etc/os-release && echo "$ID")"
	fi

	lsb_dist="$(echo "$lsb_dist" \| tr '[:upper:]' '[:lower:]')"

	case "$lsb_dist" in

	ubuntu)
	if command_exists lsb_release; then
	dist_version="$(lsb_release --codename \| cut -f2)"
	fi
	if [ -z "$dist_version" ] && [ -r /etc/lsb-release ]; then
	dist_version="$(. /etc/lsb-release && echo "$DISTRIB_CODENAME")"
	fi
	;;

	debian)
	dist_version="$(cat /etc/debian_version \| sed 's/\/.//' \| sed 's/\..//')"
	case "$dist_version" in
	8)
	dist_version="jessie"
	;;
	7)
	dist_version="wheezy"
	;;
	esac
	;;

	oracleserver)
	# need to switch lsb_dist to match yum repo URL
	lsb_dist="oraclelinux"
	dist_version="$(rpm -q --whatprovides redhat-release --queryformat "%{VERSION}\n" \| sed 's/\/.//' \| sed 's/\..//' \| sed 's/Server*//')"
	;;

	fedora\|centos)
	dist_version="$(rpm -q --whatprovides redhat-release --queryformat "%{VERSION}\n" \| sed 's/\/.//' \| sed 's/\..//' \| sed 's/Server*//')"
	;;

	*)
	if command_exists lsb_release; then
	dist_version="$(lsb_release --codename \| cut -f2)"
	fi
	if [ -z "$dist_version" ] && [ -r /etc/os-release ]; then
	dist_version="$(. /etc/os-release && echo "$VERSION_ID")"
	fi
	;;


	esac

	# Check if this is a forked Linux distro
	check_forked

	# Run setup for each distro accordingly
	case "$lsb_dist" in
	amzn)
	(
	set -x
	$sh_c 'sleep 3; yum -y -q install docker'
	)
	echo_docker_as_nonroot
	exit 0
	;;

	'opensuse project'\|opensuse\|'suse linux'\|sle[sd])
	(
	set -x
	$sh_c 'sleep 3; zypper -n install docker'
	)
	echo_docker_as_nonroot
	exit 0
	;;

	ubuntu\|debian)
	export DEBIAN_FRONTEND=noninteractive

	did_apt_get_update=
	apt_get_update() {
	if [ -z "$did_apt_get_update" ]; then
	( set -x; $sh_c 'sleep 3; apt-get update' )
	did_apt_get_update=1
	fi
	}

	# aufs is preferred over devicemapper; try to ensure the driver is available.
	if ! grep -q aufs /proc/filesystems && ! $sh_c 'modprobe aufs'; then
	if uname -r \| grep -q -- '-generic' && dpkg -l 'linux-image-*-generic' \| grep -q '^ii' 2>/dev/null; then
	kern_extras="linux-image-extra-$(uname -r) linux-image-extra-virtual"

	apt_get_update
	( set -x; $sh_c 'sleep 3; apt-get install -y -q '"$kern_extras" ) \|\| true

	if ! grep -q aufs /proc/filesystems && ! $sh_c 'modprobe aufs'; then
	echo >&2 'Warning: tried to install '"$kern_extras"' (for AUFS)'
	echo >&2 ' but we still have no AUFS. Docker may not work. Proceeding anyways!'
	( set -x; sleep 10 )
	fi
	else
	echo >&2 'Warning: current kernel is not supported by the linux-image-extra-virtual'
	echo >&2 ' package. We have no AUFS support. Consider installing the packages'
	echo >&2 ' linux-image-virtual kernel and linux-image-extra-virtual for AUFS support.'
	( set -x; sleep 10 )
	fi
	fi

	# install apparmor utils if they're missing and apparmor is enabled in the kernel
	# otherwise Docker will fail to start
	if [ "$(cat /sys/module/apparmor/parameters/enabled 2>/dev/null)" = 'Y' ]; then
	if command -v apparmor_parser >/dev/null 2>&1; then
	echo 'apparmor is enabled in the kernel and apparmor utils were already installed'
	else
	echo 'apparmor is enabled in the kernel, but apparmor_parser missing'
	apt_get_update
	( set -x; $sh_c 'sleep 3; apt-get install -y -q apparmor' )
	fi
	fi

	if [ ! -e /usr/lib/apt/methods/https ]; then
	apt_get_update
	( set -x; $sh_c 'sleep 3; apt-get install -y -q apt-transport-https ca-certificates' )
	fi
	if [ -z "$curl" ]; then
	apt_get_update
	( set -x; $sh_c 'sleep 3; apt-get install -y -q curl ca-certificates' )
	curl='curl -sSL'
	fi
	(
	set -x
	$sh_c "apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D"
	$sh_c "mkdir -p /etc/apt/sources.list.d"
	$sh_c "echo deb https://apt.dockerproject.org/repo ${lsb_dist}-${dist_version} ${repo} > /etc/apt/sources.list.d/docker.list"
	$sh_c 'sleep 3; apt-get update; apt-get install -y -q docker-engine'
	)
	echo_docker_as_nonroot
	exit 0
	;;

	fedora\|centos\|oraclelinux)
	$sh_c "cat >/etc/yum.repos.d/docker-${repo}.repo" <<-EOF
	[docker-${repo}-repo]
	name=Docker ${repo} Repository
	baseurl=https://yum.dockerproject.org/repo/${repo}/${lsb_dist}/${dist_version}
	enabled=1
	gpgcheck=1
	gpgkey=https://yum.dockerproject.org/gpg
	EOF
	if [ "$lsb_dist" = "fedora" ] && [ "$dist_version" -ge "22" ]; then
	(
	set -x
	$sh_c 'sleep 3; dnf -y -q install docker-engine'
	)
	else
	(
	set -x
	$sh_c 'sleep 3; yum -y -q install docker-engine'
	)
	fi
	echo_docker_as_nonroot
	exit 0
	;;
	gentoo)
	if [ "$url" = "https://test.docker.com/" ]; then
	# intentionally mixed spaces and tabs here -- tabs are stripped by "<<-'EOF'", spaces are kept in the output
	cat >&2 <<-'EOF'

	You appear to be trying to install the latest nightly build in Gentoo.'
	The portage tree should contain the latest stable release of Docker, but'
	if you want something more recent, you can always use the live ebuild'
	provided in the "docker" overlay available via layman. For more'
	instructions, please see the following URL:'

	https://github.com/tianon/docker-overlay#using-this-overlay'

	After adding the "docker" overlay, you should be able to:'

	emerge -av =app-emulation/docker-9999'

	EOF
	exit 1
	fi

	(
	set -x
	$sh_c 'sleep 3; emerge app-emulation/docker'
	)
	exit 0
	;;
	esac

	# intentionally mixed spaces and tabs here -- tabs are stripped by "<<-'EOF'", spaces are kept in the output
	cat >&2 <<-'EOF'

	Either your platform is not easily detectable, is not supported by this
	installer script (yet - PRs welcome! [hack/install.sh]), or does not yet have
	a package for Docker. Please visit the following URL for more detailed
	installation instructions:

	https://docs.docker.com/en/latest/installation/

	EOF
	exit 1
	}

	# wrapped up in a function so that we have some protection against only getting
	# half the file during "curl \| sh"
	do_install