docker-init: add DHCP support

gns3server/modules/docker/resources/bin/udhcpc

@@ -0,0 +1,3 @@
+#!/tmp/gns3/bin/sh
+
+exec busybox udhcpc -s /gns3/etc/udhcpc/default.script "$@"

gns3server/modules/docker/resources/bin/udhcpc6

@@ -0,0 +1,3 @@
+#!/tmp/gns3/bin/sh
+
+exec busybox udhcpc6 -s /gns3/etc/udhcpc/default.script "$@"

gns3server/modules/docker/resources/etc/udhcpc/default.script

@@ -0,0 +1,138 @@
+#!/tmp/gns3/bin/sh
+
+# script for udhcpc
+# Copyright (c) 2008 Natanael Copa <natanael.copa@gmail.com>
+
+UDHCPC="/gns3/etc/udhcpc"
+UDHCPC_CONF="$UDHCPC/udhcpc.conf"
+
+RESOLV_CONF="/etc/resolv.conf"
+[ -f $UDHCPC_CONF ] && . $UDHCPC_CONF
+
+export broadcast
+export dns
+export domain
+export interface
+export ip
+export mask
+export metric
+export router
+export subnet
+
+#export PATH=/usr/bin:/bin:/usr/sbin:/sbin
+
+run_scripts() {
+	local dir=$1
+	if [ -d $dir ]; then
+		for i in $dir/*; do
+			[ -f $i ] && $i
+		done
+	fi
+}
+
+deconfig() {
+	ip addr flush dev $interface
+}
+
+is_wifi() {
+	test -e /sys/class/net/$interface/phy80211
+}
+
+if_index() {
+	if [ -e  /sys/class/net/$interface/ifindex ]; then
+		cat /sys/class/net/$interface/ifindex
+	else
+		ip link show dev $interface | head -n1 | cut -d: -f1
+	fi
+}
+
+calc_metric() {
+	local base=
+	if is_wifi; then
+		base=300
+	else
+		base=200
+	fi
+	echo $(( $base + $(if_index) ))
+}
+
+routes() {
+	[ -z "$router" ] && return
+	local gw= num=
+	while ip route del default via dev $interface 2>/dev/null; do
+		:
+	done
+	num=0
+	for gw in $router; do
+		ip route add 0.0.0.0/0 via $gw dev $interface \
+			metric $(( $num + ${IF_METRIC:-$(calc_metric)} ))
+		num=$(( $num + 1 ))
+	done
+}
+
+resolvconf() {
+	local i
+	[ -n "$IF_PEER_DNS" ] && [ "$IF_PEER_DNS" != "yes" ] && return
+	if [ "$RESOLV_CONF" = "no" ] || [ "$RESOLV_CONF" = "NO" ] \
+			|| [ -z "$RESOLV_CONF" ]; then
+		return
+	fi
+	echo -n > "$RESOLV_CONF"
+	[ -n "$domain" ] && echo "search $domain" >> "$RESOLV_CONF"
+	for i in $dns; do
+		echo "nameserver $i" >> "$RESOLV_CONF"
+	done
+}
+
+bound() {
+	ip addr add $ip/$mask ${broadcast:+broadcast $broadcast} dev $interface
+	ip link set dev $interface up
+	routes
+	resolvconf
+}
+
+renew() {
+	if ! ip addr show dev $interface | grep $ip/$mask; then
+		ip addr flush dev $interface
+		ip addr add $ip/$mask ${broadcast:+broadcast $broadcast} dev $interface
+	fi
+
+	local i
+	for i in $router; do
+		if ! ip route show | grep ^default | grep $i; then
+			routes
+			break
+		fi
+	done
+
+	if ! grep "^search $domain"; then
+		resolvconf
+		return
+	fi
+	for i in $dns; do
+		if ! grep "^nameserver $i"; then
+			resolvconf
+			return
+		fi
+	done
+}
+
+case "$1" in
+	deconfig|renew|bound)
+		run_scripts $UDHCPC/pre-$1
+		$1
+		run_scripts $UDHCPC/post-$1
+		;;
+	leasefail)
+		echo "udhcpc failed to get a DHCP lease" >&2
+		;;
+	nak)
+		echo "udhcpc received DHCP NAK" >&2
+		;;
+	*)
+		echo "Error: this script should be called from udhcpc" >&2
+		exit 1
+		;;
+esac
+exit 0
+

gns3server/modules/docker/resources/init.sh

@@ -26,6 +26,8 @@ PATH=/gns3/bin:/tmp/gns3/bin
 if [ ! -d /tmp/gns3/bin ]; then
 	busybox mkdir -p /tmp/gns3/bin
 	/gns3/bin/busybox --install -s /tmp/gns3/bin
+	# remove commands already available in /gns3/bin
+	(cd /tmp/gns3/bin; rm -f `cd /gns3/bin; echo *`)
 fi
 
 # Wait 2 seconds to settle the network interfaces
@@ -51,8 +53,10 @@ sed -n 's/^ *\(eth[0-9]*\):.*/\1/p' < /proc/net/dev | while read dev; do
 done
 
 if [ -n "$INTERFACES" ]; then
+	mkdir -p /etc/network/if-up.d /etc/network/if-pre-up.d
+	mkdir -p /etc/network/if-down.d /etc/network/if-post-down.d
 	echo -e "$INTERFACES" > /etc/network/interfaces
-	ifup -a
+	ifup -a -f
 fi
 
 # continue normal docker startup