#!/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 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 [ "$_DOCKERD_ROOTLESS_CHILD" = 1 ] # remove the symlinks for the existing files in the parent namespace if any, # so that we can create our own files in our mount namespace. rm -f /run/docker /run/containerd /run/xtables.lock if [ -n "$_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 [ "$(stat -c %T -f /etc)" = "tmpfs" ] && [ -L "/etc/ssl" ]; then # Workaround for "x509: certificate signed by unknown authority" on openSUSE Tumbleweed. # https://github.com/rootless-containers/rootlesskit/issues/225 realpath_etc_ssl=$(realpath /etc/ssl) rm -f /etc/ssl mkdir /etc/ssl mount --rbind ${realpath_etc_ssl} /etc/ssl fi exec "$dockerd" "$@" fi