From 795670b3350fd70c121fa7de0d04ff3d9e10259d Mon Sep 17 00:00:00 2001
From: Fijxu <fijxu@nadeko.net>
Date: Sun, 24 Mar 2024 01:37:43 -0300
Subject: [PATCH] Add missing dockerd-entrypoint.sh

---
 forgejo-runner-dind/dockerd-entrypoint.sh | 233 ++++++++++++++++++++++
 1 file changed, 233 insertions(+)
 create mode 100644 forgejo-runner-dind/dockerd-entrypoint.sh

diff --git a/forgejo-runner-dind/dockerd-entrypoint.sh b/forgejo-runner-dind/dockerd-entrypoint.sh
new file mode 100644
index 0000000..b7aa0ea
--- /dev/null
+++ b/forgejo-runner-dind/dockerd-entrypoint.sh
@@ -0,0 +1,233 @@
+#!/bin/sh
+set -eu
+
+_tls_ensure_private() {
+	local f="$1"; shift
+	[ -s "$f" ] || openssl genrsa -out "$f" 4096
+}
+_tls_san() {
+	{
+		ip -oneline address | awk '{ gsub(/\/.+$/, "", $4); print "IP:" $4 }'
+		{
+			cat /etc/hostname
+			echo 'docker'
+			echo 'localhost'
+			hostname -f
+			hostname -s
+		} | sed 's/^/DNS:/'
+		[ -z "${DOCKER_TLS_SAN:-}" ] || echo "$DOCKER_TLS_SAN"
+	} | sort -u | xargs printf '%s,' | sed "s/,\$//"
+}
+_tls_generate_certs() {
+	local dir="$1"; shift
+
+	# if server/{ca,key,cert}.pem && !ca/key.pem, do NOTHING except verify (user likely managing CA themselves)
+	# if ca/key.pem || !ca/cert.pem, generate CA public if necessary
+	# if ca/key.pem, generate server public
+	# if ca/key.pem, generate client public
+	# (regenerating public certs every startup to account for SAN/IP changes and/or expiration)
+
+	if [ -s "$dir/server/ca.pem" ] && [ -s "$dir/server/cert.pem" ] && [ -s "$dir/server/key.pem" ] && [ ! -s "$dir/ca/key.pem" ]; then
+		openssl verify -CAfile "$dir/server/ca.pem" "$dir/server/cert.pem"
+		return 0
+	fi
+
+	# https://github.com/FiloSottile/mkcert/issues/174
+	local certValidDays='825'
+
+	if [ -s "$dir/ca/key.pem" ] || [ ! -s "$dir/ca/cert.pem" ]; then
+		# if we either have a CA private key or do *not* have a CA public key, then we should create/manage the CA
+		mkdir -p "$dir/ca"
+		_tls_ensure_private "$dir/ca/key.pem"
+		openssl req -new -key "$dir/ca/key.pem" \
+			-out "$dir/ca/cert.pem" \
+			-subj '/CN=docker:dind CA' -x509 -days "$certValidDays"
+	fi
+
+	if [ -s "$dir/ca/key.pem" ]; then
+		# if we have a CA private key, we should create/manage a server key
+		mkdir -p "$dir/server"
+		_tls_ensure_private "$dir/server/key.pem"
+		openssl req -new -key "$dir/server/key.pem" \
+			-out "$dir/server/csr.pem" \
+			-subj '/CN=docker:dind server'
+		cat > "$dir/server/openssl.cnf" <<-EOF
+			[ x509_exts ]
+			subjectAltName = $(_tls_san)
+		EOF
+		openssl x509 -req \
+				-in "$dir/server/csr.pem" \
+				-CA "$dir/ca/cert.pem" \
+				-CAkey "$dir/ca/key.pem" \
+				-CAcreateserial \
+				-out "$dir/server/cert.pem" \
+				-days "$certValidDays" \
+				-extfile "$dir/server/openssl.cnf" \
+				-extensions x509_exts
+		cp "$dir/ca/cert.pem" "$dir/server/ca.pem"
+		openssl verify -CAfile "$dir/server/ca.pem" "$dir/server/cert.pem"
+	fi
+
+	if [ -s "$dir/ca/key.pem" ]; then
+		# if we have a CA private key, we should create/manage a client key
+		mkdir -p "$dir/client"
+		_tls_ensure_private "$dir/client/key.pem"
+		chmod 0644 "$dir/client/key.pem" # openssl defaults to 0600 for the private key, but this one needs to be shared with arbitrary client contexts
+		openssl req -new \
+				-key "$dir/client/key.pem" \
+				-out "$dir/client/csr.pem" \
+				-subj '/CN=docker:dind client'
+		cat > "$dir/client/openssl.cnf" <<-'EOF'
+			[ x509_exts ]
+			extendedKeyUsage = clientAuth
+		EOF
+		openssl x509 -req \
+				-in "$dir/client/csr.pem" \
+				-CA "$dir/ca/cert.pem" \
+				-CAkey "$dir/ca/key.pem" \
+				-CAcreateserial \
+				-out "$dir/client/cert.pem" \
+				-days "$certValidDays" \
+				-extfile "$dir/client/openssl.cnf" \
+				-extensions x509_exts
+		cp "$dir/ca/cert.pem" "$dir/client/ca.pem"
+		openssl verify -CAfile "$dir/client/ca.pem" "$dir/client/cert.pem"
+	fi
+}
+
+# no arguments passed
+# or first arg is `-f` or `--some-option`
+if [ "$#" -eq 0 ] || [ "${1#-}" != "$1" ]; then
+	# set "dockerSocket" to the default "--host" *unix socket* value (for both standard or rootless)
+	uid="$(id -u)"
+	if [ "$uid" = '0' ]; then
+		dockerSocket='unix:///var/run/docker.sock'
+	else
+		# if we're not root, we must be trying to run rootless
+		: "${XDG_RUNTIME_DIR:=/run/user/$uid}"
+		dockerSocket="unix://$XDG_RUNTIME_DIR/docker.sock"
+	fi
+	case "${DOCKER_HOST:-}" in
+		unix://*)
+			dockerSocket="$DOCKER_HOST"
+			;;
+	esac
+
+	# add our default arguments
+	if [ -n "${DOCKER_TLS_CERTDIR:-}" ]; then
+		_tls_generate_certs "$DOCKER_TLS_CERTDIR"
+		# generate certs and use TLS if requested/possible (default in 19.03+)
+		set -- dockerd \
+			--host="$dockerSocket" \
+			--host=tcp://0.0.0.0:2376 \
+			--tlsverify \
+			--tlscacert "$DOCKER_TLS_CERTDIR/server/ca.pem" \
+			--tlscert "$DOCKER_TLS_CERTDIR/server/cert.pem" \
+			--tlskey "$DOCKER_TLS_CERTDIR/server/key.pem" \
+			"$@"
+		DOCKERD_ROOTLESS_ROOTLESSKIT_FLAGS="${DOCKERD_ROOTLESS_ROOTLESSKIT_FLAGS:-} -p 0.0.0.0:2376:2376/tcp"
+	else
+		# TLS disabled (-e DOCKER_TLS_CERTDIR='') or missing certs
+		set -- dockerd \
+			--host="$dockerSocket" \
+			--host=tcp://0.0.0.0:2375 \
+			"$@"
+		DOCKERD_ROOTLESS_ROOTLESSKIT_FLAGS="${DOCKERD_ROOTLESS_ROOTLESSKIT_FLAGS:-} -p 0.0.0.0:2375:2375/tcp"
+	fi
+fi
+
+if [ "$1" = 'dockerd' ]; then
+	# explicitly remove Docker's default PID file to ensure that it can start properly if it was stopped uncleanly (and thus didn't clean up the PID file)
+	find /run /var/run -iname 'docker*.pid' -delete || :
+
+	# XXX inject "docker-init" (tini) as pid1 to workaround https://github.com/docker-library/docker/issues/318 (zombie container-shim processes)
+	set -- docker-init -- "$@"
+
+	iptablesLegacy=
+	if [ -n "${DOCKER_IPTABLES_LEGACY+x}" ]; then
+		# let users choose explicitly to legacy or not to legacy
+		iptablesLegacy="$DOCKER_IPTABLES_LEGACY"
+		if [ -n "$iptablesLegacy" ]; then
+			modprobe ip_tables || :
+		else
+			modprobe nf_tables || :
+		fi
+	elif (
+		# https://git.netfilter.org/iptables/tree/iptables/nft-shared.c?id=f5cf76626d95d2c491a80288bccc160c53b44e88#n420
+		# https://github.com/docker-library/docker/pull/468#discussion_r1442131459
+		for f in /proc/net/ip_tables_names /proc/net/ip6_tables_names /proc/net/arp_tables_names; do
+			if b="$(cat "$f")" && [ -n "$b" ]; then
+				exit 0
+			fi
+		done
+		exit 1
+	); then
+		# if we already have any "legacy" iptables rules, we should always use legacy
+		iptablesLegacy=1
+	elif ! iptables -nL > /dev/null 2>&1; then
+		# if iptables fails to run, chances are high the necessary kernel modules aren't loaded (perhaps the host is using xtables, for example)
+		# https://github.com/docker-library/docker/issues/350
+		# https://github.com/moby/moby/issues/26824
+		# https://github.com/docker-library/docker/pull/437#issuecomment-1854900620
+		modprobe nf_tables || :
+		if ! iptables -nL > /dev/null 2>&1; then
+			# might be host has no nf_tables, but Alpine is all-in now (so let's try a legacy fallback)
+			modprobe ip_tables || :
+			if /usr/local/sbin/.iptables-legacy/iptables -nL > /dev/null 2>&1; then
+				iptablesLegacy=1
+			fi
+		fi
+	fi
+	if [ -n "$iptablesLegacy" ]; then
+		# see https://github.com/docker-library/docker/issues/463 (and the dind Dockerfile where this directory is set up)
+		export PATH="/usr/local/sbin/.iptables-legacy:$PATH"
+	fi
+	iptables --version # so users can see whether it's legacy or not
+
+	uid="$(id -u)"
+	if [ "$uid" != '0' ]; then
+		# if we're not root, we must be trying to run rootless
+		if ! command -v rootlesskit > /dev/null; then
+			echo >&2 "error: attempting to run rootless dockerd but missing 'rootlesskit' (perhaps the 'docker:dind-rootless' image variant is intended?)"
+			exit 1
+		fi
+		user="$(id -un 2>/dev/null || :)"
+		if ! grep -qE "^($uid${user:+|$user}):" /etc/subuid || ! grep -qE "^($uid${user:+|$user}):" /etc/subgid; then
+			echo >&2 "error: attempting to run rootless dockerd but missing necessary entries in /etc/subuid and/or /etc/subgid for $uid"
+			exit 1
+		fi
+		: "${XDG_RUNTIME_DIR:=/run/user/$uid}"
+		export XDG_RUNTIME_DIR
+		if ! mkdir -p "$XDG_RUNTIME_DIR" || [ ! -w "$XDG_RUNTIME_DIR" ] || ! mkdir -p "$HOME/.local/share/docker" || [ ! -w "$HOME/.local/share/docker" ]; then
+			echo >&2 "error: attempting to run rootless dockerd but need writable HOME ($HOME) and XDG_RUNTIME_DIR ($XDG_RUNTIME_DIR) for user $uid"
+			exit 1
+		fi
+		if [ -f /proc/sys/kernel/unprivileged_userns_clone ] && unprivClone="$(cat /proc/sys/kernel/unprivileged_userns_clone)" && [ "$unprivClone" != '1' ]; then
+			echo >&2 "error: attempting to run rootless dockerd but need 'kernel.unprivileged_userns_clone' (/proc/sys/kernel/unprivileged_userns_clone) set to 1"
+			exit 1
+		fi
+		if [ -f /proc/sys/user/max_user_namespaces ] && maxUserns="$(cat /proc/sys/user/max_user_namespaces)" && [ "$maxUserns" = '0' ]; then
+			echo >&2 "error: attempting to run rootless dockerd but need 'user.max_user_namespaces' (/proc/sys/user/max_user_namespaces) set to a sufficiently large value"
+			exit 1
+		fi
+		# TODO overlay support detection?
+		exec rootlesskit \
+			--net="${DOCKERD_ROOTLESS_ROOTLESSKIT_NET:-vpnkit}" \
+			--mtu="${DOCKERD_ROOTLESS_ROOTLESSKIT_MTU:-1500}" \
+			--disable-host-loopback \
+			--port-driver=builtin \
+			--copy-up=/etc \
+			--copy-up=/run \
+			${DOCKERD_ROOTLESS_ROOTLESSKIT_FLAGS:-} \
+			"$@"
+	elif [ -x '/usr/local/bin/dind' ]; then
+		# if we have the (mostly defunct now) Docker-in-Docker wrapper script, use it
+		set -- '/usr/local/bin/dind' "$@"
+	fi
+else
+	# if it isn't `dockerd` we're trying to run, pass it through `docker-entrypoint.sh` so it gets `DOCKER_HOST` set appropriately too
+	set -- docker-entrypoint.sh "$@"
+fi
+
+exec "$@"
+