Add options to update-component-sh.sh to modify by image name or by tag

Signed-off-by: Avi Deitcher <avi@deitcher.net>

scripts/update-component-sha.sh

@@ -1,10 +1,67 @@
 #!/bin/sh
 set -e
-if [ $# -ne 2 ] ; then
+
-    echo "Need <OLD> and <NEW> as arguments" >&2
+##
+#
+# script to replace hashes in config files
+# see usage() for usage and functionality
+#
+
+function usage() {
+    cat >&2 <<EOF
+$0 --<mode> <how-to-find> <new-hash>
+
+Available modes: --hash and --image
+
+Replace by hash:
+	$0 --hash <OLD> <NEW>
+	Example: $0 8675309abcdefg abcdef567899
+    	   Will replace all instances of 8675309abcdefg with abcdef567899
+
+Replace by image: $0 --image <IMAGE> <NEW>
+	$0 --image <IMAGE> <NEW>
+	Example: $0 linuxkit/foo abcdef567899
+	   Will tag all instances of linuxkit/foo with abcdef567899
+
+By default, for convenience, if no mode is given (--image or --hash), the first method (--hash) is assumed. 
+Thus the following are equivalent:
+	$0 <OLD> <NEW>
+	$0 --hash <OLD> <NEW>
+
+EOF
+}
+
+
+# backwards compatibility
+if [ $# -eq 2 ]; then
+  set -- "--hash" "$1" "$2"
+fi
+
+# sufficient arguments
+if [ $# -ne 3 ] ; then
+    usage
     exit 1
 fi
-old=$1
-new=$2
 
-git grep -l "$old" | xargs sed -i -e "s,$old,$new,g"
+
+# which mode?
+case "$1" in
+    --hash)
+        old=$2
+        new=$3
+
+        git grep -w -l "\b$old\b" | xargs sed -i.bak -e "s,$old,$new,g"
+        ;;
+    --image)
+        image=$2
+        hash=$3
+        git grep -E -l "\b$image:" | xargs sed -i.bak -e "s,$image:[[:xdigit:]]"'\{40\}'",$image:$hash,g"
+        ;;
+    *)
+        echo "Unknown mode $1"
+        usage
+        exit 1
+        ;;
+esac
+
+find . -name '*.bak' | xargs rm