Add mechanism to send error messages to helper.

Adds a new err_msg function which is used to:

-echo feedback to the deploy ramdisk console
-keep track of the first error message we hit so
 that we can send it along to the baremetal-deploy-helper.

Also, updates our wget request back to baremetal-deploy-helper
to include the first the first error message (if any) as
the 'e' parameter.

The err_msg uses a new simple safe_url_encode function to ensure
we don't send invalid characters in our HTTP post requests.

Change-Id: I5a623a6f66cde8d81ff1e75800dc2953ca2703a8

elements/deploy/init

@@ -1,5 +1,5 @@
 if [ -z "$ISCSI_TARGET_IQN" ]; then
-  echo "iscsi_target_iqn is not defined"
+  err_msg "iscsi_target_iqn is not defined"
   troubleshoot
 fi
 
@@ -13,19 +13,19 @@ while ! target_disk=$(find_disk "$DISK"); do
 done
 
 if [ -z "$target_disk" ]; then
-  echo "Could not find disk to use."
+  err_msg "Could not find disk to use."
   troubleshoot
 fi
 
 echo "start iSCSI target on $target_disk"
 start_iscsi_target "$ISCSI_TARGET_IQN" "$target_disk" ALL
 if [ $? -ne 0 ]; then
-  echo "Failed to start iscsi target."
+  err_msg "Failed to start iscsi target."
   troubleshoot
 fi
 
 echo "request boot server to deploy image"
-d="i=$DEPLOYMENT_ID&k=$DEPLOYMENT_KEY&a=$BOOT_IP_ADDRESS&n=$ISCSI_TARGET_IQN"
+d="i=$DEPLOYMENT_ID&k=$DEPLOYMENT_KEY&a=$BOOT_IP_ADDRESS&n=$ISCSI_TARGET_IQN&e=$FIRST_ERR_MSG"
 wget --post-data "$d" "http://$BOOT_SERVER:10000"
 
 echo "waiting for notice of complete"

scripts/d/init-func

@@ -195,3 +195,33 @@ function troubleshoot() {
 	fi
 }
 
+function safe_url_encode() {
+	local str=$1
+	local out=""
+
+	for (( i=0; i<${#str}; i++ )); do
+		c=${str:$i:1}
+		case $c in
+		[a-zA-Z0-9.-_] )
+			out+="$c"
+			;;
+		' ' )
+			out+="+"
+			;;
+		*)
+			#skip it
+			;;
+		esac
+	done
+	echo "$out"
+
+}
+
+function err_msg() {
+	message=$1
+	if [ -z "$FIRST_ERR_MSG" ]; then
+		FIRST_ERR_MSG=$(safe_url_encode "$message")
+	fi
+	echo "$message"
+}
+

scripts/init

@@ -48,6 +48,7 @@ readonly DEPLOYMENT_ID=$(get_kernel_parameter deployment_id)
 readonly DEPLOYMENT_KEY=$(get_kernel_parameter deployment_key)
 readonly ISCSI_TARGET_IQN=$(get_kernel_parameter iscsi_target_iqn)
 readonly TROUBLESHOOT=$(get_kernel_parameter troubleshoot)
+FIRST_ERR_MSG=
 
 mount -t sysfs none /sys
 
@@ -110,7 +111,7 @@ while ! BOOT_INTERFACE=$(find_interface "$BOOT_MAC_ADDRESS"); do
 	sleep 5
 done
 if [ -z "$BOOT_INTERFACE" ]; then
-	echo "could not find an interface owns MAC=$BOOT_MAC_ADDRESS"
+	err_msg "Could not find an interface that owns MAC: $BOOT_MAC_ADDRESS"
 	troubleshoot
 fi
 
@@ -122,7 +123,7 @@ if [ $? -ne 0 ]; then
 	sleep 10
 	ifconfig "$BOOT_INTERFACE" up
 	if [ $? -ne 0 ]; then
-		echo "Failed to up $BOOT_INTERFACE"
+		err_msg "Failed to ifconfig up $BOOT_INTERFACE"
 		troubleshoot
 	fi
 fi