contrib/dockerd-rootless.sh - third_party/docker - Git at Google


            
            #!/bin/sh

            
            # dockerd-rootless.sh executes dockerd in rootless mode.

            
            #

            
            # Usage: dockerd-rootless.sh [DOCKERD_OPTIONS]

            
            #

            
            # External dependencies:

            
            # * newuidmap and newgidmap needs to be installed.

            
            # * /etc/subuid and /etc/subgid needs to be configured for the current user.

            
            # * Either one of slirp4netns (>= v0.4.0), VPNKit, lxc-user-nic needs to be installed.

            
            #

            
            # Recognized environment variables:

            
            # * DOCKERD_ROOTLESS_ROOTLESSKIT_STATE_DIR=DIR: the rootlesskit state dir. Defaults to "$XDG_RUNTIME_DIR/dockerd-rootless".

            
            # * DOCKERD_ROOTLESS_ROOTLESSKIT_NET=(slirp4netns|vpnkit|pasta|lxc-user-nic): the rootlesskit network driver. Defaults to "slirp4netns" if slirp4netns (>= v0.4.0) is installed. Otherwise defaults to "vpnkit".

            
            # * DOCKERD_ROOTLESS_ROOTLESSKIT_MTU=NUM: the MTU value for the rootlesskit network driver. Defaults to 65520 for slirp4netns, 1500 for other drivers.

            
            # * DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER=(builtin|slirp4netns|implicit): the rootlesskit port driver. Defaults to "builtin".

            
            # * DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SANDBOX=(auto|true|false): whether to protect slirp4netns with a dedicated mount namespace. Defaults to "auto".

            
            # * DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SECCOMP=(auto|true|false): whether to protect slirp4netns with seccomp. Defaults to "auto".

            
            # * DOCKERD_ROOTLESS_ROOTLESSKIT_DISABLE_HOST_LOOPBACK=(true|false): prohibit connections to 127.0.0.1 on the host (including via 10.0.2.2, in the case of slirp4netns). Defaults to "true".


            # To apply an environment variable via systemd, create ~/.config/systemd/user/docker.service.d/override.conf as follows,

            
            # and run `systemctl --user daemon-reload && systemctl --user restart docker`:

            
            # --- BEGIN ---

            
            # [Service]

            
            # Environment="DOCKERD_ROOTLESS_ROOTLESSKIT_NET=pasta"

            
            # Environment="DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER=implicit"

            
            # ---  END  ---


            # Guide to choose the network driver and the port driver:

            
            #

            
            #  Network driver | Port driver    | Net throughput | Port throughput | Src IP | No SUID | Note

            
            #  ---------------|----------------|----------------|-----------------|--------|---------|---------------------------------------------------------

            
            #  slirp4netns    | builtin        | Slow           | Fast ✅         | ❌     | ✅      | Default in typical setup

            
            #  vpnkit         | builtin        | Slow           | Fast ✅         | ❌     | ✅      | Default when slirp4netns is not installed

            
            #  slirp4netns    | slirp4netns    | Slow           | Slow            | ✅     | ✅      |

            
            #  pasta          | implicit       | Slow           | Fast ✅         | ✅     | ✅      | Experimental; Needs recent version of pasta (2023_12_04)

            
            #  lxc-user-nic   | builtin        | Fast ✅        | Fast ✅         | ❌     | ❌      | Experimental

            
            #  (bypass4netns) | (bypass4netns) | Fast ✅        | Fast ✅         | ✅     | ✅      | (Not integrated to RootlessKit)


            # See the documentation for the further information: https://docs.docker.com/go/rootless/


            set -e -x

            
            case "$1" in

            
            	"check" | "install" | "uninstall")

            
            		echo "Did you mean 'dockerd-rootless-setuptool.sh $@' ?"

            
            		exit 1

            
            		;;

            
            esac

            
            if ! [ -w "$XDG_RUNTIME_DIR" ]; then

            
            	echo "XDG_RUNTIME_DIR needs to be set and writable"

            
            	exit 1

            
            fi

            
            if ! [ -d "$HOME" ]; then

            
            	echo "HOME needs to be set and exist."

            
            	exit 1

            
            fi


            mount_directory() {

            
            	if [ -z "$_DOCKERD_ROOTLESS_CHILD" ]; then

            
            		echo "mount_directory should be called from the child context. Otherwise data loss is at risk" >&2

            
            		exit 1

            
            	fi


            	DIRECTORY="$1"

            
            	if [ ! -d "$DIRECTORY" ]; then

            
            		return

            
            	fi


            	# Bind mount directory: this makes this directory visible to

            
            	# Dockerd, even if it is originally a symlink, given Dockerd does

            
            	# not always follow symlinks. Some directories might also be

            
            	# "copied-up", meaning that they will also be writable on the child

            
            	# namespace; this will be the case only if they are provided as

            
            	# --copy-up to the rootlesskit.

            
            	DIRECTORY_REALPATH=$(realpath "$DIRECTORY")

            
            	MOUNT_OPTIONS="${2:---bind}"

            
            	rm -rf "$DIRECTORY"

            
            	mkdir -p "$DIRECTORY"

            
            	mount $MOUNT_OPTIONS "$DIRECTORY_REALPATH" "$DIRECTORY"

            
            }


            rootlesskit=""

            
            for f in docker-rootlesskit rootlesskit; do

            
            	if command -v $f > /dev/null 2>&1; then

            
            		rootlesskit=$f

            
            		break

            
            	fi

            
            done

            
            if [ -z "$rootlesskit" ]; then

            
            	echo "rootlesskit needs to be installed"

            
            	exit 1

            
            fi


            : "${DOCKERD_ROOTLESS_ROOTLESSKIT_STATE_DIR:=$XDG_RUNTIME_DIR/dockerd-rootless}"

            
            : "${DOCKERD_ROOTLESS_ROOTLESSKIT_NET:=}"

            
            : "${DOCKERD_ROOTLESS_ROOTLESSKIT_MTU:=}"

            
            : "${DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER:=builtin}"

            
            : "${DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SANDBOX:=auto}"

            
            : "${DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SECCOMP:=auto}"

            
            : "${DOCKERD_ROOTLESS_ROOTLESSKIT_DISABLE_HOST_LOOPBACK:=}"

            
            net=$DOCKERD_ROOTLESS_ROOTLESSKIT_NET

            
            mtu=$DOCKERD_ROOTLESS_ROOTLESSKIT_MTU

            
            if [ -z "$net" ]; then

            
            	if command -v slirp4netns > /dev/null 2>&1; then

            
            		# If --netns-type is present in --help, slirp4netns is >= v0.4.0.

            
            		if slirp4netns --help | grep -qw -- --netns-type; then

            
            			net=slirp4netns

            
            			if [ -z "$mtu" ]; then

            
            				mtu=65520

            
            			fi

            
            		else

            
            			echo "slirp4netns found but seems older than v0.4.0. Falling back to VPNKit."

            
            		fi

            
            	fi

            
            	if [ -z "$net" ]; then

            
            		if command -v vpnkit > /dev/null 2>&1; then

            
            			net=vpnkit

            
            		else

            
            			echo "Either slirp4netns (>= v0.4.0) or vpnkit needs to be installed"

            
            			exit 1

            
            		fi

            
            	fi

            
            fi

            
            if [ -z "$mtu" ]; then

            
            	mtu=1500

            
            fi


            host_loopback="--disable-host-loopback"

            
            if [ "$DOCKERD_ROOTLESS_ROOTLESSKIT_DISABLE_HOST_LOOPBACK" = "false" ]; then

            
            	host_loopback=""

            
            fi


            dockerd="${DOCKERD:-dockerd}"


            if [ -z "$_DOCKERD_ROOTLESS_CHILD" ]; then

            
            	_DOCKERD_ROOTLESS_CHILD=1

            
            	export _DOCKERD_ROOTLESS_CHILD

            
            	if [ "$(id -u)" = "0" ]; then

            
            		echo "This script must be executed as a non-privileged user"

            
            		exit 1

            
            	fi

            
            	# `selinuxenabled` always returns false in RootlessKit child, so we execute `selinuxenabled` in the parent.

            
            	# https://github.com/rootless-containers/rootlesskit/issues/94

            
            	if command -v selinuxenabled > /dev/null 2>&1 && selinuxenabled; then

            
            		_DOCKERD_ROOTLESS_SELINUX=1

            
            		export _DOCKERD_ROOTLESS_SELINUX

            
            	fi

            
            	# Re-exec the script via RootlessKit, so as to create unprivileged {user,mount,network} namespaces.

            
            	#

            
            	# --copy-up allows removing/creating files in the directories by creating tmpfs and symlinks

            
            	# * /etc: copy-up is required so as to prevent `/etc/resolv.conf` in the

            
            	#         namespace from being unexpectedly unmounted when `/etc/resolv.conf` is recreated on the host

            
            	#         (by either systemd-networkd or NetworkManager)

            
            	# * /run: copy-up is required so that we can create /run/docker (hardcoded for plugins) in our namespace

            
            	exec $rootlesskit \

            
            		--state-dir=$DOCKERD_ROOTLESS_ROOTLESSKIT_STATE_DIR \

            
            		--net=$net --mtu=$mtu \

            
            		--slirp4netns-sandbox=$DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SANDBOX \

            
            		--slirp4netns-seccomp=$DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SECCOMP \

            
            		$host_loopback --port-driver=$DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER \

            
            		--copy-up=/etc --copy-up=/run \

            
            		--propagation=rslave \

            
            		$DOCKERD_ROOTLESS_ROOTLESSKIT_FLAGS \

            
            		"$0" "$@"

            
            else

            
            	[ "$_DOCKERD_ROOTLESS_CHILD" = 1 ]


            	# The Container Device Interface (CDI) specs can be found by default

            
            	# under {/etc,/var/run}/cdi. More information at:

            
            	# https://github.com/cncf-tags/container-device-interface

            
            	#

            
            	# In order to use the Container Device Interface (CDI) integration,

            
            	# the CDI paths need to exist before the Docker daemon is started in

            
            	# order for it to read the CDI specification files. Otherwise, a

            
            	# Docker daemon restart will be required for the daemon to discover

            
            	# them.

            
            	#

            
            	# If another set of CDI paths (other than the default /etc/cdi and

            
            	# /var/run/cdi) are configured through the Docker configuration file

            
            	# (using "cdi-spec-dirs"), they need to be bind mounted in rootless

            
            	# mode; otherwise the Docker daemon won't have access to the CDI

            
            	# specification files.

            
            	mount_directory /etc/cdi

            
            	mount_directory /var/run/cdi


            	# remove the symlinks for the existing files in the parent namespace if any,

            
            	# so that we can create our own files in our mount namespace.

            
            	rm -f /run/docker /run/containerd /run/xtables.lock


            	if [ -n "$_DOCKERD_ROOTLESS_SELINUX" ]; then

            
            		# iptables requires /run in the child to be relabeled. The actual /run in the parent is unaffected.

            
            		# https://github.com/containers/podman/blob/e6fc34b71aa9d876b1218efe90e14f8b912b0603/libpod/networking_linux.go#L396-L401

            
            		# https://github.com/moby/moby/issues/41230

            
            		chcon system_u:object_r:iptables_var_run_t:s0 /run

            
            	fi


            	if [ "$(stat -c %T -f /etc)" = "tmpfs" ] && [ -L "/etc/ssl" ]; then

            
            		# Workaround for "x509: certificate signed by unknown authority" on openSUSE Tumbleweed.

            
            		# https://github.com/rootless-containers/rootlesskit/issues/225

            
            		mount_directory /etc/ssl "--rbind"

            
            	fi


            	exec "$dockerd" "$@"

            
            fi
	#!/bin/sh
	# dockerd-rootless.sh executes dockerd in rootless mode.
	#
	# Usage: dockerd-rootless.sh [DOCKERD_OPTIONS]
	#
	# External dependencies:
	# * newuidmap and newgidmap needs to be installed.
	# * /etc/subuid and /etc/subgid needs to be configured for the current user.
	# * Either one of slirp4netns (>= v0.4.0), VPNKit, lxc-user-nic needs to be installed.
	#
	# Recognized environment variables:
	# * DOCKERD_ROOTLESS_ROOTLESSKIT_STATE_DIR=DIR: the rootlesskit state dir. Defaults to "$XDG_RUNTIME_DIR/dockerd-rootless".
	# * DOCKERD_ROOTLESS_ROOTLESSKIT_NET=(slirp4netns\|vpnkit\|pasta\|lxc-user-nic): the rootlesskit network driver. Defaults to "slirp4netns" if slirp4netns (>= v0.4.0) is installed. Otherwise defaults to "vpnkit".
	# * DOCKERD_ROOTLESS_ROOTLESSKIT_MTU=NUM: the MTU value for the rootlesskit network driver. Defaults to 65520 for slirp4netns, 1500 for other drivers.
	# * DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER=(builtin\|slirp4netns\|implicit): the rootlesskit port driver. Defaults to "builtin".
	# * DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SANDBOX=(auto\|true\|false): whether to protect slirp4netns with a dedicated mount namespace. Defaults to "auto".
	# * DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SECCOMP=(auto\|true\|false): whether to protect slirp4netns with seccomp. Defaults to "auto".
	# * DOCKERD_ROOTLESS_ROOTLESSKIT_DISABLE_HOST_LOOPBACK=(true\|false): prohibit connections to 127.0.0.1 on the host (including via 10.0.2.2, in the case of slirp4netns). Defaults to "true".

	# To apply an environment variable via systemd, create ~/.config/systemd/user/docker.service.d/override.conf as follows,
	# and run `systemctl --user daemon-reload && systemctl --user restart docker`:
	# --- BEGIN ---
	# [Service]
	# Environment="DOCKERD_ROOTLESS_ROOTLESSKIT_NET=pasta"
	# Environment="DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER=implicit"
	# --- END ---

	# Guide to choose the network driver and the port driver:
	#
	# Network driver \| Port driver \| Net throughput \| Port throughput \| Src IP \| No SUID \| Note
	# ---------------\|----------------\|----------------\|-----------------\|--------\|---------\|---------------------------------------------------------
	# slirp4netns \| builtin \| Slow \| Fast ✅ \| ❌ \| ✅ \| Default in typical setup
	# vpnkit \| builtin \| Slow \| Fast ✅ \| ❌ \| ✅ \| Default when slirp4netns is not installed
	# slirp4netns \| slirp4netns \| Slow \| Slow \| ✅ \| ✅ \|
	# pasta \| implicit \| Slow \| Fast ✅ \| ✅ \| ✅ \| Experimental; Needs recent version of pasta (2023_12_04)
	# lxc-user-nic \| builtin \| Fast ✅ \| Fast ✅ \| ❌ \| ❌ \| Experimental
	# (bypass4netns) \| (bypass4netns) \| Fast ✅ \| Fast ✅ \| ✅ \| ✅ \| (Not integrated to RootlessKit)

	# See the documentation for the further information: https://docs.docker.com/go/rootless/

	set -e -x
	case "$1" in
	"check" \| "install" \| "uninstall")
	echo "Did you mean 'dockerd-rootless-setuptool.sh $@' ?"
	exit 1
	;;
	esac
	if ! [ -w "$XDG_RUNTIME_DIR" ]; then
	echo "XDG_RUNTIME_DIR needs to be set and writable"
	exit 1
	fi
	if ! [ -d "$HOME" ]; then
	echo "HOME needs to be set and exist."
	exit 1
	fi

	mount_directory() {
	if [ -z "$_DOCKERD_ROOTLESS_CHILD" ]; then
	echo "mount_directory should be called from the child context. Otherwise data loss is at risk" >&2
	exit 1
	fi

	DIRECTORY="$1"
	if [ ! -d "$DIRECTORY" ]; then
	return
	fi

	# Bind mount directory: this makes this directory visible to
	# Dockerd, even if it is originally a symlink, given Dockerd does
	# not always follow symlinks. Some directories might also be
	# "copied-up", meaning that they will also be writable on the child
	# namespace; this will be the case only if they are provided as
	# --copy-up to the rootlesskit.
	DIRECTORY_REALPATH=$(realpath "$DIRECTORY")
	MOUNT_OPTIONS="${2:---bind}"
	rm -rf "$DIRECTORY"
	mkdir -p "$DIRECTORY"
	mount $MOUNT_OPTIONS "$DIRECTORY_REALPATH" "$DIRECTORY"
	}

	rootlesskit=""
	for f in docker-rootlesskit rootlesskit; do
	if command -v $f > /dev/null 2>&1; then
	rootlesskit=$f
	break
	fi
	done
	if [ -z "$rootlesskit" ]; then
	echo "rootlesskit needs to be installed"
	exit 1
	fi

	: "${DOCKERD_ROOTLESS_ROOTLESSKIT_STATE_DIR:=$XDG_RUNTIME_DIR/dockerd-rootless}"
	: "${DOCKERD_ROOTLESS_ROOTLESSKIT_NET:=}"
	: "${DOCKERD_ROOTLESS_ROOTLESSKIT_MTU:=}"
	: "${DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER:=builtin}"
	: "${DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SANDBOX:=auto}"
	: "${DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SECCOMP:=auto}"
	: "${DOCKERD_ROOTLESS_ROOTLESSKIT_DISABLE_HOST_LOOPBACK:=}"
	net=$DOCKERD_ROOTLESS_ROOTLESSKIT_NET
	mtu=$DOCKERD_ROOTLESS_ROOTLESSKIT_MTU
	if [ -z "$net" ]; then
	if command -v slirp4netns > /dev/null 2>&1; then
	# If --netns-type is present in --help, slirp4netns is >= v0.4.0.
	if slirp4netns --help \| grep -qw -- --netns-type; then
	net=slirp4netns
	if [ -z "$mtu" ]; then
	mtu=65520
	fi
	else
	echo "slirp4netns found but seems older than v0.4.0. Falling back to VPNKit."
	fi
	fi
	if [ -z "$net" ]; then
	if command -v vpnkit > /dev/null 2>&1; then
	net=vpnkit
	else
	echo "Either slirp4netns (>= v0.4.0) or vpnkit needs to be installed"
	exit 1
	fi
	fi
	fi
	if [ -z "$mtu" ]; then
	mtu=1500
	fi

	host_loopback="--disable-host-loopback"
	if [ "$DOCKERD_ROOTLESS_ROOTLESSKIT_DISABLE_HOST_LOOPBACK" = "false" ]; then
	host_loopback=""
	fi

	dockerd="${DOCKERD:-dockerd}"

	if [ -z "$_DOCKERD_ROOTLESS_CHILD" ]; then
	_DOCKERD_ROOTLESS_CHILD=1
	export _DOCKERD_ROOTLESS_CHILD
	if [ "$(id -u)" = "0" ]; then
	echo "This script must be executed as a non-privileged user"
	exit 1
	fi
	# `selinuxenabled` always returns false in RootlessKit child, so we execute `selinuxenabled` in the parent.
	# https://github.com/rootless-containers/rootlesskit/issues/94
	if command -v selinuxenabled > /dev/null 2>&1 && selinuxenabled; then
	_DOCKERD_ROOTLESS_SELINUX=1
	export _DOCKERD_ROOTLESS_SELINUX
	fi
	# Re-exec the script via RootlessKit, so as to create unprivileged {user,mount,network} namespaces.
	#
	# --copy-up allows removing/creating files in the directories by creating tmpfs and symlinks
	# * /etc: copy-up is required so as to prevent `/etc/resolv.conf` in the
	# namespace from being unexpectedly unmounted when `/etc/resolv.conf` is recreated on the host
	# (by either systemd-networkd or NetworkManager)
	# * /run: copy-up is required so that we can create /run/docker (hardcoded for plugins) in our namespace
	exec $rootlesskit \
	--state-dir=$DOCKERD_ROOTLESS_ROOTLESSKIT_STATE_DIR \
	--net=$net --mtu=$mtu \
	--slirp4netns-sandbox=$DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SANDBOX \
	--slirp4netns-seccomp=$DOCKERD_ROOTLESS_ROOTLESSKIT_SLIRP4NETNS_SECCOMP \
	$host_loopback --port-driver=$DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER \
	--copy-up=/etc --copy-up=/run \
	--propagation=rslave \
	$DOCKERD_ROOTLESS_ROOTLESSKIT_FLAGS \
	"$0" "$@"
	else
	[ "$_DOCKERD_ROOTLESS_CHILD" = 1 ]

	# The Container Device Interface (CDI) specs can be found by default
	# under {/etc,/var/run}/cdi. More information at:
	# https://github.com/cncf-tags/container-device-interface
	#
	# In order to use the Container Device Interface (CDI) integration,
	# the CDI paths need to exist before the Docker daemon is started in
	# order for it to read the CDI specification files. Otherwise, a
	# Docker daemon restart will be required for the daemon to discover
	# them.
	#
	# If another set of CDI paths (other than the default /etc/cdi and
	# /var/run/cdi) are configured through the Docker configuration file
	# (using "cdi-spec-dirs"), they need to be bind mounted in rootless
	# mode; otherwise the Docker daemon won't have access to the CDI
	# specification files.
	mount_directory /etc/cdi
	mount_directory /var/run/cdi

	# remove the symlinks for the existing files in the parent namespace if any,
	# so that we can create our own files in our mount namespace.
	rm -f /run/docker /run/containerd /run/xtables.lock

	if [ -n "$_DOCKERD_ROOTLESS_SELINUX" ]; then
	# iptables requires /run in the child to be relabeled. The actual /run in the parent is unaffected.
	# https://github.com/containers/podman/blob/e6fc34b71aa9d876b1218efe90e14f8b912b0603/libpod/networking_linux.go#L396-L401
	# https://github.com/moby/moby/issues/41230
	chcon system_u:object_r:iptables_var_run_t:s0 /run
	fi

	if [ "$(stat -c %T -f /etc)" = "tmpfs" ] && [ -L "/etc/ssl" ]; then
	# Workaround for "x509: certificate signed by unknown authority" on openSUSE Tumbleweed.
	# https://github.com/rootless-containers/rootlesskit/issues/225
	mount_directory /etc/ssl "--rbind"
	fi

	exec "$dockerd" "$@"
	fi