From aafca3813aa62ed7c83ec9e824a4515d81c0d39d Mon Sep 17 00:00:00 2001
From: Hamish Coleman <hamish@zot.org>
Date: Mon, 1 Nov 2021 10:39:25 +0000
Subject: [PATCH] Use script to calculate the build version

---
 CMakeLists.txt     | 31 +++++--------------------------
 configure.ac       |  4 ++--
 doc/Scripts.md     |  8 ++++++++
 scripts/version.sh | 42 ++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 57 insertions(+), 28 deletions(-)
 create mode 100755 scripts/version.sh

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 3252dd6..ea6ab36 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,39 +6,18 @@ SET(CMAKE_VERBOSE_MAKEFILE ON)
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
 
 # N2n release information
+set(N2N_OSNAME ${CMAKE_SYSTEM_NAME})
 execute_process(
-        COMMAND cat VERSION
+        COMMAND scripts/version.sh
         WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
         OUTPUT_VARIABLE PACKAGE_VERSION
 )
 string(STRIP "${PACKAGE_VERSION}" PACKAGE_VERSION)
-set(N2N_OSNAME ${CMAKE_SYSTEM_NAME})
-execute_process(
-        COMMAND git status
-        WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
-        OUTPUT_VARIABLE GIT_OUTPUT
-        RESULT_VARIABLE GIT_ERROR_CODE
-)
-if (GIT_ERROR_CODE EQUAL 0)
-execute_process(
-        COMMAND git rev-list --count HEAD
-        WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
-        OUTPUT_VARIABLE GIT_REV
-)
-execute_process(
-        COMMAND git rev-parse --short HEAD
-        WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}
-        OUTPUT_VARIABLE GIT_ID
-)
-string(REGEX REPLACE "\n$" "" GIT_REV "${GIT_REV}")
-string(REGEX REPLACE "\n$" "" GIT_ID "${GIT_ID}")
-set(N2N_VERSION "${N2N_VERSION}.r${GIT_REV}.${GIT_ID}")
-MESSAGE(STATUS "Build from git rev: ${N2N_VERSION}")
-endif (GIT_ERROR_CODE EQUAL 0)
+MESSAGE(STATUS "Build for version: ${PACKAGE_VERSION}")
 
 add_definitions(-DCMAKE_BUILD)
-add_definitions(-DPACKAGE_OSNAME="${N2N_OSNAME}")
-add_definitions(-DPACKAGE_VERSION="${PACKAGE_VERSION}" -DN2N_OSNAME="${N2N_OSNAME}")
+add_definitions(-DPACKAGE_OSNAME="${N2N_OSNAME}" -DN2N_OSNAME="${N2N_OSNAME}")
+add_definitions(-DPACKAGE_VERSION="${PACKAGE_VERSION}")
 
 
 # Build information
diff --git a/configure.ac b/configure.ac
index f7ca2f5..2d267ca 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,8 +1,8 @@
 odnl> Do not add anything above
-AC_INIT([edge], m4_esyscmd([cat VERSION | tr -d '\n']))
+AC_INIT([edge], m4_esyscmd([scripts/version.sh | tr -d '\n']))
 dnl> Do not add anything above
 
-N2N_VERSION_SHORT=${PACKAGE_VERSION}
+N2N_VERSION_SHORT=$(scripts/version.sh short)
 
 if test -d ".git"; then
 # NOTE: keep in sync with the definitions for configure.in files under the packages folder
diff --git a/doc/Scripts.md b/doc/Scripts.md
index b946ca1..0f2f2cd 100644
--- a/doc/Scripts.md
+++ b/doc/Scripts.md
@@ -59,3 +59,11 @@ This shell script is used to run automated tests during development.
 
 A sample script to route all the host traffic towards a remote gateway,
 which is reachable via the n2n virtual interface.
+
+### `version.sh`
+
+This script is used to determine the current version number during the
+build process.
+
+It looks at both the VERSION file and the GIT tags and outputs the
+version number to use.
diff --git a/scripts/version.sh b/scripts/version.sh
new file mode 100755
index 0000000..5713c0a
--- /dev/null
+++ b/scripts/version.sh
@@ -0,0 +1,42 @@
+#!/bin/sh
+#
+# Output the current version number
+#
+
+usage() {
+    echo "Usage: $0 [short]"
+    echo
+    echo "Determine the correct version number for the current build"
+    exit 0
+}
+
+# TODO: search for the top dir that contains the VERSION file?
+VER_FILE_SHORT=$(cat VERSION)
+
+if git status >/dev/null; then
+    VER_GIT_SHORT=$(git describe --abbrev=0)
+    VER_GIT=$(git describe --abbrev=7 --dirty)
+
+    if [ "$VER_FILE_SHORT" != "$VER_GIT_SHORT" ]; then
+        echo "Error: VERSION file does not match tag version ($VER_FILE_SHORT != $VER_GIT_SHORT)"
+        exit 1
+    fi
+
+    VER_SHORT="$VER_GIT_SHORT"
+    VER="$VER_GIT"
+else
+    VER_SHORT="$VER_FILE_SHORT"
+    VER="$VER_FILE_SHORT"
+fi
+
+case "$1" in
+    short)
+        echo "$VER_SHORT"
+        ;;
+    "")
+        echo "$VER"
+        ;;
+    *)
+        usage
+        ;;
+esac