scripts: add 'BOM' update script

Need this script when we add external dependencies.

Signed-off-by: Gyu-Ho Lee <gyuhox@gmail.com>

bill-of-materials.json

@@ -1,4 +1,9 @@
 [
+	{
+		"project": "bitbucket.org/ww/goautoneg",
+		"license": "BSD 3-clause \"New\" or \"Revised\" License",
+		"confidence": 1
+	},
 	{
 		"project": "github.com/beorn7/perks/quantile",
 		"license": "MIT License",
@@ -203,10 +208,5 @@
 		"project": "gopkg.in/yaml.v2",
 		"license": "Apache License 2.0 and MIT License",
 		"confidence": 1
-	},
-	{
-		"project": "bitbucket.org/ww/goautoneg",
-		"license": "BSD 3-clause \"New\" or \"Revised\" License",
-		"confidence": 1
 	}
 ]

scripts/updatebom.sh

@@ -0,0 +1,25 @@
+#!/usr/bin/env bash
+
+set -e
+
+if ! [[ "$0" =~ "scripts/updatebom.sh" ]]; then
+	echo "must be run from repository root"
+	exit 255
+fi
+
+echo "installing 'bill-of-materials.json'"
+go get -v -u github.com/coreos/license-bill-of-materials
+
+rm -rf ./gopath
+mkdir ./gopath
+
+mv ./cmd/vendor ./gopath/src
+
+GOPATH=`pwd`/gopath license-bill-of-materials \
+    --override-file ./bill-of-materials.override.json \
+    github.com/coreos/etcd github.com/coreos/etcd/etcdctl > bill-of-materials.json
+
+mv ./gopath/src ./cmd/vendor
+rm -rf ./gopath
+
+echo "bill-of-materials is finished"