Tox: Add copyright year tox checker

Only added/edited files already containing copyright notice
are checked for the correct year (and only if in first 3 lines).

Change-Id: I22c057431847fda3a7dfd4577f8346fadfe4c4f6
Signed-off-by: Vratko Polak <vrpolak@cisco.com>

1 files changed, 70 insertions, 0 deletions

diff --git a/resources/libraries/bash/entry/check/copyright_year.sh b/resources/libraries/bash/entry/check/copyright_year.sh
new file mode 100644
index 0000000000..66667b96ca
--- /dev/null
+++ b/resources/libraries/bash/entry/check/copyright_year.sh
@@ -0,0 +1,70 @@
+# Copyright (c) 2020 Cisco and/or its affiliates.
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at:
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -exuo pipefail
+
+# This file should be executed from tox, as the assumed working directory
+# is different from where this file is located.
+# This file does not have executable flag nor shebang,
+# to dissuade non-tox callers.
+
+# This script runs a few grep-based command and fails
+# if it detects any file edited or added since HEAD~
+# containing a copyright notice in first 3 lines,
+# but not the current year (in the same line).
+# The offending lines are stored to copyright_year.log (overwriting).
+#
+# 3 lines were chosen, because first two lines could be shebang and empty line,
+# and more than 3 lines would start failing on files with multiple copyright
+# holders. There, only the last updating entity needs to bump its year,
+# and put other copyright lines below.
+
+# "set -eu" handles failures from the following two lines.
+BASH_CHECKS_DIR="$(dirname $(readlink -e "${BASH_SOURCE[0]}"))"
+BASH_FUNCTION_DIR="$(readlink -e "${BASH_CHECKS_DIR}/../../function")"
+source "${BASH_FUNCTION_DIR}/common.sh" || {
+    echo "Source failed." >&2
+    exit 1
+}
+
+year=$(date +'%Y')
+IFS=$'\n'
+files=($(git diff --name-only HEAD~ || true))
+unset IFS
+truncate -s 0 "copyright_year.log" || die
+# A change can have thousands of files, supress console output in the cycle.
+set +x
+for fil in "${files[@]}"; do
+    # Greps do "fail" on 0 line output, we need to ignore that
+    # as 0 lines is good. We need both set +e to ensure everything executes,
+    # and || true later to avoid dying on zero.
+    piped_command="set +ex; head -n 3 '${fil}' | fgrep -i 'Copyright'"
+    piped_command+=" | fgrep -v '${year}' | awk '{print \"${fil}: \" \$0}'"
+    piped_command+=" >> 'copyright_year.log'"
+    wrong_strings="$(bash -c "${piped_command}" || true)" || die
+done
+set -x
+lines="$(< "copyright_year.log" wc -l)"
+if [ "${lines}" != "0" ]; then
+    # TODO: Decide which text goes to stdout and which to stderr.
+    warn "Copyright lines with wrong year detected: ${lines}"
+    # TODO: Disable when output size does more harm than good.
+    pwd
+    cat "copyright_year.log" >&2
+    warn
+    warn "Copyright year checker: FAIL"
+    exit 1
+fi
+
+warn
+warn "Copyright year checker: PASS"