Further fleshing out of hwdiscovery element

This adds support for other elements to feed into the hwdiscovery
results.

It also fixes a few bugs in the construction of the ramdisk.

It also adds support for specifying a server to POST the discovered
hardware data to, via the kernel command line

Change-Id: I163db2b1388f908880e8f458e16906fa6f9db7bc

elements/hwdiscovery/README.md

@@ -1 +1,35 @@
 A ramdisk to report the hardware of a machine to an inventory service.
+
+This will collect up some basic information about the hardware it 
+boots on:
+
+ * CPU cores
+ * RAM
+ * Disk
+ * NIC mac address
+
+This information will then be collated into a JSON document, base64 
+encoded and passed, via HTTP POST, to a URL that you must specify on 
+the kernel commandline, thus:
+
+HW_DISCOVERY_URL=http://1.2.3.4:56/hw_script.asp
+
+
+This is currently fairly fragile as there can be a huge variability in 
+the number of disks/NICs in servers and how they are configured.
+
+If other elements wish to inject data into the hardware discovery data, 
+they can - they should be specified before hwdiscovery to the image 
+building script, and they should contain something like this in their 
+init fragment:
+
+_vendor_hwdiscovery_data="$_vendor_hwdiscovery_data
+ \"some vendor key\" : \"some data you care about\",
+ \"some other vendor key\" : \"some other data you care about\","
+
+Note that you are essentially feeding JSON into the main hwdiscovery 
+JSON.
+
+This will allow any number of vendor specific hwdiscovery elements to 
+chain together their JSON fragments and maintain consistency.
+

elements/hwdiscovery/binary-deps

@@ -1,3 +1,5 @@
 lshw
 hwinfo
 dhclient
+wget
+base64

elements/hwdiscovery/init

@@ -19,6 +19,7 @@ function pxe_mac() {
   _dev=$(echo "${_info1}" | grep "Device File:"|awk -F':' {'print $2'}|tr -d ' ')
   _mac=$(echo "${_info2}" | grep "HW Address:"|awk -F'ss:' {'print $2'}|tr -d ' ')
   echo $_mac
+  export HW_DISCOVERY_BOOT_IFACE="$_mac"
 }
 
 function disk() {
@@ -35,7 +36,7 @@ function raw_network() {
   hwinfo --network
 }
 
-cat <<EOF
+HW_DISCOVERY_OUTPUT=$(cat <<EOF
 {
   "cpu cores" : "$(cpu_cores)",
   "disk size" : "$(disk)",
@@ -44,9 +45,19 @@ cat <<EOF
   "extra data" : {
     "raw disk" : "$(raw_disk | base64)",
     "raw network" : "$(raw_network | base64)",
+    $_vendor_hwdiscovery_data
   }
 }
 EOF
+)
+
+# Print the resulting JSON for debugging purposes
+echo $HW_DISCOVERY_OUTPUT
+
+# Now submit the JSON
+HW_DISCOVERY_DATA=$(echo ${HW_DISCOVERY_OUTPUT} | base64)
+HW_DISCOVERY_URL=$(get_kernel_parameter HW_DISCOVERY_URL)
+wget --post-data "hwdiscovery=true&hwdiscovery_data=${HW_DISCOVERY_DATA}" ${HW_DISCOVERY_URL}
 
 sleep 30