Use git describe to determine the version

ci/version.sh

@@ -1,30 +1,18 @@
 #!/bin/bash
 
-# This script extracts the project's current version from git. If there is a
-# tag attached to the current commit (of the form "v1.0.1"), then it will be
-# used ("1.0.1"), otherwise the first 7 characters of the hash of the current
-# commit will be used ("eb757a8"). The result will be saved to a "version"
-# file.
+# This script extracts the project's current version from git using
+# `git describe`, which determines the version based on the latest tag, such as:
+#
+#     $ git describe --tags --dirty
+#     v0.6.0-37-g3878937f-dirty
+#
+# Each tag starts with "v", so we strip the "v", and the final version becomes:
+#
+#     0.6.0-37-g3878937f-dirty
+#
 
-set -e
-set -x
+set -ex
 
-if [[ $CI_COMMIT_SHA == "" ]]; then
-    # Use sha and tag values provided by git (requires git to be installed)
-    COMMIT_TAG=$(git tag -l --points-at HEAD)
-    COMMIT_SHA=$(git rev-parse HEAD)
-else
-    # Use sha and tag variables provides by the CI
-    COMMIT_TAG=${CI_COMMIT_TAG}
-    COMMIT_SHA=${CI_COMMIT_SHA}
-fi
-
-if [[ $COMMIT_TAG == "" ]]; then
-    # The commit is not tagged, use the first 7 chars of git commit hash
-    version="0.0+git${COMMIT_SHA:0:7}"
-else
-    # The commit is tagged, convert tag version properly:v1.0.1 -> "1.0.1"
-    version=${COMMIT_TAG:1}
-fi
-
-echo ${version} > version
+version=$(git describe --tags --dirty)
+version="${version:1}"
+echo $version > version