tools: add git-version to print a package version from git references

Author: illwieckz

tools/git-version/git-version

@@ -0,0 +1,96 @@
+#! /usr/bin/env python3
+
+# Daemon BSD Source Code
+# Copyright (c) 2024, Daemon Developers
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#  * Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+#  * Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in the
+#    documentation and/or other materials provided with the distribution.
+#  * Neither the name of the <organization> nor the
+#    names of its contributors may be used to endorse or promote products
+#    derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+import datetime
+import os
+import subprocess
+import sys
+import time
+
+class GitVersion():
+	def __init__(self, repository_dir):
+		if not os.path.isdir(repository_dir):
+			raise(ValueError, "not a directory")
+
+		self.git_command_list = ["git", "-C", repository_dir]
+
+	def runGitCommand(self, command_list):
+		command_list = self.git_command_list + command_list
+		return subprocess.run(command_list, stdout=subprocess.PIPE, stderr=subprocess.DEVNULL).stdout.decode("utf-8").rstrip()
+
+	def testGitCommand(self, command_list):
+		command_list = self.git_command_list + command_list
+		return subprocess.run(command_list, stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL).returncode
+
+	def getDate(self, timestamp):
+		return datetime.datetime.utcfromtimestamp(timestamp).strftime('%Y%m%d-%H%M%S')
+
+	def printVersion(self):
+		tag_string="0"
+		date_string=""
+		ref_string=""
+		dirt_string=""
+
+		git_last_commit_short = self.runGitCommand(["rev-parse", "HEAD"])[:7]
+
+		if git_last_commit_short:
+			git_describe_string = self.runGitCommand(["describe", "--tags", "--match", "v[0-9].*"])[1:]
+
+			git_last_commit_timestamp = int(self.runGitCommand(["log", "-1", "--pretty=format:%ct"]))
+			git_last_commit_date = self.getDate(git_last_commit_timestamp)
+
+			git_closest_tag = self.runGitCommand(["describe", "--tags", "--abbrev=0", "--match", "v[0-9].*"])[1:]
+
+			if git_closest_tag:
+				tag_string = git_closest_tag
+
+				if git_closest_tag != git_describe_string:
+					date_string = "-" + git_last_commit_date
+					ref_string = "-" + git_last_commit_short
+			else:
+				date_string = "-" + git_last_commit_date
+				ref_string = "-" + git_last_commit_short
+		else:
+			date_string = "-" + self.getDate(time.time())
+			ref_string = "-0"
+
+		if self.testGitCommand(["diff", "--quiet"]) != 0:
+			dirt_string = '+dirty'
+
+		print(tag_string + date_string + ref_string + dirt_string)
+
+if __name__ == "__main__":
+	if len(sys.argv) == 1:
+		repository_dir = os.getcwd()
+	elif len(sys.argv) == 2:
+		repository_dir = sys.argv[1]
+	else:
+		raise(ValueError, "too many arguments")
+
+	gitVersion = GitVersion(repository_dir)
+	gitVersion.printVersion()