[FAB-5431] Adopt Go SDK's check_license.sh

Per Troy's suggestion on FAB-5431, this changes
the check_license.sh script to the one used in the
Go SDK.
This version doesn't return an error if the SPDX Id
is not used but will return an error if no Apache license
is found.

Change-Id: I731b6b7e8a84aebb10052371de2c241867ae9f33
Signed-off-by: Arnaud J Le Hors <lehors@us.ibm.com>

Author: lehors

scripts/check_license.sh

@@ -1,22 +1,33 @@
 #!/bin/bash
 #
-# Copyright IBM Corp. All Rights Reserved.
+# Copyright IBM Corp, SecureKey Technologies Inc. All Rights Reserved.
 #
 # SPDX-License-Identifier: Apache-2.0
 #
 
-CHECK=$(git diff --name-only HEAD * | grep -v .png$ | grep -v .rst$ | grep -v .git \
-  | grep -v .md$ | grep -v ^vendor/ | grep -v ^build/ | grep -v .pb.go$ | grep -v .txt | sort -u)
+function filterExcludedFiles {
+  CHECK=`echo "$CHECK" | grep -v .png$ | grep -v .rst$ | grep -v ^.git/ \
+  | grep -v .pem$ | grep -v .block$ | grep -v .tx$ | grep -v ^LICENSE$ | grep -v _sk$ \
+  | grep -v .key$ | grep -v \\.gen.go$ | grep -v ^Gopkg.lock$ \
+  | grep -v .md$ | grep -v ^vendor/ | grep -v ^build/ | grep -v .pb.go$ | sort -u`
+}
+
+CHECK=$(git diff --name-only HEAD --diff-filter=ACMRTUXB *)
+filterExcludedFiles
 
 if [[ -z "$CHECK" ]]; then
-  CHECK=$(git diff-tree --no-commit-id --name-only -r $(git log -2 \
-    --pretty=format:"%h") | grep -v .png$ | grep -v .rst$ | grep -v .git \
-    | grep -v .md$ | grep -v ^vendor/ | grep -v ^build/ | grep -v .pb.go$ | grep -v .txt | sort -u)
+  CHECK=$(git diff-tree --no-commit-id --name-only --diff-filter=ACMRTUXB -r $(git log -2 \
+    --pretty=format:"%h"))
+    filterExcludedFiles
+fi
+
+if [[ -z "$CHECK" ]]; then
+   echo "All files are excluded from having license headers"
+   exit 0
 fi
 
-echo "Checking committed files for SPDX-License-Identifier headers ..."
-missing=`echo $CHECK | xargs grep -L "SPDX-License-Identifier"`
-if [ -z "$missing" ]; then
+missing=`echo "$CHECK" | xargs ls -d 2>/dev/null | xargs grep -L "SPDX-License-Identifier"`
+if [[ -z "$missing" ]]; then
    echo "All files have SPDX-License-Identifier headers"
    exit 0
 fi
@@ -25,4 +36,15 @@ echo "$missing"
 echo
 echo "Please replace the Apache license header comment text with:"
 echo "SPDX-License-Identifier: Apache-2.0"
+
+echo
+echo "Checking committed files for traditional Apache License headers ..."
+missing=`echo "$missing" | xargs ls -d 2>/dev/null | xargs grep -L "http://www.apache.org/licenses/LICENSE-2.0"`
+if [[ -z "$missing" ]]; then
+   echo "All remaining files have Apache 2.0 headers"
+   exit 0
+fi
+echo "The following files are missing traditional Apache 2.0 headers:"
+echo "$missing"
+echo "Fatal Error - All files must have a license header"
 exit 1