report version on Docker container startup

Author: Vladimir Kotal

Dockerfile

@@ -36,6 +36,9 @@ RUN mvn -DskipTests=true -Dmaven.javadoc.skip=true -B -V package
 # hadolint ignore=SC2012,DL4006
 RUN cp `ls -t distribution/target/*.tar.gz | head -1` /opengrok.tar.gz
 
+# Store the version in a file so that the tools can report it.
+RUN mvn help:evaluate -Dexpression=project.version -q -DforceStdout > /mvn/VERSION
+
 FROM tomcat:10-jdk11
 LABEL maintainer="https://github.com/oracle/opengrok"
 
@@ -66,6 +69,8 @@ RUN mkdir -p /opengrok /opengrok/etc /opengrok/data /opengrok/src && \
     python3 -m pip install --no-cache-dir /opengrok/tools/opengrok-tools* && \
     python3 -m pip install --no-cache-dir Flask Flask-HTTPAuth waitress # for /reindex REST endpoint handled by start.py
 
+COPY --from=build /mvn/VERSION /opengrok/VERSION
+
 # environment variables
 ENV SRC_ROOT /opengrok/src
 ENV DATA_ROOT /opengrok/data

docker/start.py

@@ -467,6 +467,13 @@ def main():
 
     logger = get_console_logger(get_class_basename(), log_level)
 
+    try:
+        with open(os.path.join(OPENGROK_BASE_DIR, "VERSION"), "r") as f:
+            version = f.read()
+            logger.info("Running version {}".format(version))
+    except Exception:
+        pass
+
     uri, url_root = set_url_root(logger, os.environ.get('URL_ROOT'))
     logger.debug("URL_ROOT = {}".format(url_root))
     logger.debug("URI = {}".format(uri))