Add dhcp support for ramdisk element.

This change adds support for retrieving the IP
through DHCP if 'ip' was not provided as a kernel
command-line argument by pxelinux.  This is used
when the kernel/ramdisk is booted by virtual media.

Change-Id: I1097ce5b56ad40f2d6dc3181681d54f924ec7145
Closes-Bug: #1321563

elements/ramdisk/binary-deps.d/ramdisk

@@ -0,0 +1 @@
+dhclient

elements/ramdisk/element-deps

@@ -0,0 +1 @@
+pkg-map

elements/ramdisk/extra-data.d/scripts/init

@@ -40,10 +40,12 @@ mount -t proc proc /proc
 readonly _BOOTIF_=$(get_kernel_parameter BOOTIF)
 readonly _IP_=$(get_kernel_parameter ip)
 readonly BOOT_MAC_ADDRESS=$(echo "$_BOOTIF_" | sed -e "s/-/:/g"  | sed -e "s/^01://g" | tr 'a-f' 'A-F')
-readonly BOOT_IP_ADDRESS=$(echo "$_IP_" | cut -d':' -f1)
 readonly BOOT_SERVER=$(echo "$_IP_" | cut -d':' -f2)
-readonly BOOT_NETMASK=$(echo "$_IP_" | cut -d':' -f4)
-readonly BOOT_GATEWAY=$(echo "$_IP_" | cut -d':' -f3)
+
+# IP address and other parameters may be set later in the init script
+BOOT_IP_ADDRESS=$(echo "$_IP_" | cut -d':' -f1)
+BOOT_NETMASK=$(echo "$_IP_" | cut -d':' -f4)
+BOOT_GATEWAY=$(echo "$_IP_" | cut -d':' -f3)
 
 readonly DISK=$(get_kernel_parameter disk)
 

elements/ramdisk/init.d/02-start-network

@@ -26,20 +26,35 @@ if [ $rv -ne 0 ]; then
         troubleshoot
     fi
 fi
-ifconfig "$BOOT_INTERFACE" "$BOOT_IP_ADDRESS" netmask "$BOOT_NETMASK"
-route del default || true
-route add default gw $BOOT_GATEWAY
 
-echo "pinging to boot server $BOOT_SERVER"
-w=30
-while [ $w -gt 0 ]; do
-    ping -c 5 -q "$BOOT_SERVER" > /dev/null
-    if [ $? -eq 0 ]; then
-        break
+# Check if boot IP address was specific or retrieve from DHCP
+if [ -n "$BOOT_IP_ADDRESS" ]; then
+    ifconfig "$BOOT_INTERFACE" "$BOOT_IP_ADDRESS" netmask "$BOOT_NETMASK"
+    route del default || true
+    route add default gw $BOOT_GATEWAY
+else
+    dhclient -1 "$BOOT_INTERFACE"
+    if [[ $? == 2 ]]; then
+        echo "Error getting IP address for $BOOT_INTERFACE with MAC \
+              $BOOT_MAC_ADDRESS"
+        troubleshoot
     fi
-    sleep 1
-    w=`expr $w - 5`
-done
+
+    BOOT_IP_ADDRESS=$(ifconfig "$BOOT_INTERFACE" | grep 'inet addr:' | \
+                      cut -d: -f2 | awk '{ print $1}')
+    BOOT_NETMASK=$(ifconfig "$BOOT_INTERFACE" | grep 'Mask:' | cut -d':' -f4)
+    BOOT_GATEWAY=$(route -n | grep "$BOOT_INTERFACE" | grep '^0.0.0.0' | \
+                   awk '{print $2}')
+    echo "obtained the following from dhcp: "
+    echo " ip address = $BOOT_IP_ADDRESS"
+    echo " netmask = $BOOT_NETMASK"
+    echo " gateway = $BOOT_GATEWAY"
+fi
+
+if [ -n "$BOOT_SERVER" ]; then
+    echo "pinging to boot server $BOOT_SERVER"
+    wait_for 6 1 ping -c 5 -q "$BOOT_SERVER" > /dev/null
+fi
 
 echo "network ready"
 

elements/ramdisk/install.d/20-install-dhcp-client

@@ -2,6 +2,5 @@
 set -eux
 set -o pipefail
 
-if [ "opensuse" = "$DISTRO_NAME" ]; then
-    install-packages dhcp-client
-fi
+DHCP_CLIENT=$(pkg-map --element ramdisk dhcp_client)
+install-packages $DHCP_CLIENT

elements/ramdisk/pkg-map

@@ -0,0 +1,10 @@
+{
+  "family":{
+    "debian":{
+      "dhcp_client":"isc-dhcp-client"
+    }
+  },
+  "default":{
+    "dhcp_client":"dhclient"
+  }
+}