Support for dynamic ip ranges from urls

- Adds ipranges command to fetch ip ranges from Cloudfront and Cloudflare
- Write the ipranges file on docker start
- Support disabling ipv4 as well as ipv6 now
- Prevent disabling both

docker/rootfs/etc/s6-overlay/s6-rc.d/prepare/50-ipv46.sh

@@ -0,0 +1,58 @@
+#!/command/with-contenv bash
+# shellcheck shell=bash
+
+# This command reads the `NPM_DISABLE_IPV4` and `NPM_DISABLE_IPV6`` env vars and will either enable
+# or disable ipv6 in all nginx configs based on this setting.
+
+set -e
+
+log_info 'IPv4/IPv6 ...'
+
+DIS_4=$(is_true "$NPM_DISABLE_IPV4")
+DIS_6=$(is_true "$NPM_DISABLE_IPV6")
+
+# Ensure someone didn't misconfigure the settings
+if [ "$DIS_4" = "1" ] && [ "$DIS_6" = "1" ]; then
+	log_fatal 'NPM_DISABLE_IPV4 and NPM_DISABLE_IPV6 cannot both be set!'
+fi
+
+process_folder () {
+	FILES=$(find "$1" -type f -name "*.conf")
+	SED_REGEX=
+
+	# IPV4 ...
+	if [ "$DIS_4" = "1" ]; then
+		echo "Disabling IPV4 in hosts in: $1"
+		SED_REGEX='s/^([^#]*)listen ([0-9]+)/\1#listen \2/g'
+	else
+		echo "Enabling IPV4 in hosts in: $1"
+		SED_REGEX='s/^(\s*)#listen ([0-9]+)/\1listen \2/g'
+	fi
+
+	for FILE in $FILES
+	do
+		echo "  - ${FILE}"
+		sed -E -i "$SED_REGEX" "$FILE" || true
+	done
+
+	# IPV6 ...
+	if [ "$DIS_6" = "1" ]; then
+		echo "Disabling IPV6 in hosts in: $1"
+		SED_REGEX='s/^([^#]*)listen \[::\]/\1#listen [::]/g'
+	else
+		echo "Enabling IPV6 in hosts in: $1"
+		SED_REGEX='s/^(\s*)#listen \[::\]/\1listen [::]/g'
+	fi
+
+	for FILE in $FILES
+	do
+		echo "  - ${FILE}"
+		sed -E -i "$SED_REGEX" "$FILE" || true
+	done
+
+	# ensure the files are still owned by the npm user
+	chown -R "$PUID:$PGID" "$1"
+}
+
+process_folder /etc/nginx/conf.d
+process_folder /data/nginx