feat: add more DinD

builds/debian-dind/dockerd-entrypoint.sh

@@ -0,0 +1,58 @@
+#!/bin/sh
+set -e
+
+# Adapted from official docker-library/docker dind entrypoint
+# https://github.com/docker-library/docker/blob/master/24/dind/dockerd-entrypoint.sh
+
+if [ -z "$DOCKER_HOST" ]; then
+	case "$1" in
+		dockerd*)
+			# If we're running dockerd, we need to make sure we have cgroups mounted
+			if [ ! -d /sys/fs/cgroup ]; then
+				mkdir -p /sys/fs/cgroup
+			fi
+			if ! mountpoint -q /sys/fs/cgroup; then
+				mount -t tmpfs -o uid=0,gid=0,mode=0755 cgroup /sys/fs/cgroup
+			fi
+
+			# Mount cgroup v2 if available and not mounted
+			if [ -e /sys/fs/cgroup/cgroup.controllers ] && ! mountpoint -q /sys/fs/cgroup; then
+				mount -t cgroup2 -o nsdelegate cgroup2 /sys/fs/cgroup
+			fi
+
+			# If /sys/fs/cgroup is not a cgroup2 mount, we might need to mount cgroup v1 hierarchies
+			if ! mountpoint -q /sys/fs/cgroup || [ "$(stat -f -c %T /sys/fs/cgroup)" != "cgroup2fs" ]; then
+				if [ -d /sys/fs/cgroup/cgroup.controllers ]; then
+					# It is cgroup2 but maybe not mounted as such?
+					# Actually if it exists, it's likely v2.
+					:
+				else
+					# cgroup v1
+					for subsystem in $(awk '/^[^#]/ { print $1 }' /proc/cgroups); do
+						mkdir -p "/sys/fs/cgroup/$subsystem"
+						if ! mountpoint -q "/sys/fs/cgroup/$subsystem"; then
+							mount -t cgroup -o "$subsystem" cgroup "/sys/fs/cgroup/$subsystem"
+						fi
+					done
+				fi
+			fi
+			;;
+	esac
+fi
+
+if [ "$1" = 'dockerd' ] || [ "${1#-}" != "$1" ]; then
+	# if the first argument is "dockerd" or a flag (starts with -)
+	if [ "${1#-}" != "$1" ]; then
+		set -- dockerd "$@"
+	fi
+
+    # Explicitly use iptables-legacy if available, as it is often more stable for DinD
+    if command -v update-alternatives >/dev/null; then
+        if update-alternatives --query iptables | grep -q "iptables-legacy"; then
+            update-alternatives --set iptables /usr/sbin/iptables-legacy || true
+            update-alternatives --set ip6tables /usr/sbin/ip6tables-legacy || true
+        fi
+    fi
+fi
+
+exec "$@"