Fancify version string

Use git rev-parse and describe to pull commit sha and tag information
for use in version string.

Author: mxmeinhold

Dockerfile

@@ -33,6 +33,6 @@ RUN curl -sL https://deb.nodesource.com/setup_10.x | bash - && \
 RUN ln -sf /usr/share/zoneinfo/America/New_York /etc/localtime
 
 # Set version for apm
-RUN echo "export DD_VERSION=$(git rev-parse --short HEAD)" >> ~/.bashrc
+RUN echo "export DD_VERSION=$(python3 packet/git.py)" >> /tmp/version
 
-CMD ["/bin/bash", "-c", "source ~/.bashrc && ddtrace-run gunicorn packet:app --bind=0.0.0.0:8080 --access-logfile=- --timeout=600"]
+CMD ["/bin/bash", "-c", "source /tmp/version && ddtrace-run gunicorn packet:app --bind=0.0.0.0:8080 --access-logfile=- --timeout=600"]

packet/__init__.py

@@ -19,6 +19,8 @@
 from sentry_sdk.integrations.flask import FlaskIntegration
 from sentry_sdk.integrations.sqlalchemy import SqlalchemyIntegration
 
+from .git import get_version
+
 app = Flask(__name__)
 gzip = Gzip(app)
 
@@ -31,9 +33,8 @@
 if os.path.exists(_pyfile_config):
     app.config.from_pyfile(_pyfile_config)
 
-# Fetch the version number from the npm package file
-with open(os.path.join(_root_dir, 'package.json')) as package_file:
-    app.config['VERSION'] = json.load(package_file)['version']
+# Fetch the version number
+app.config['VERSION'] = get_version()
 
 # Logger configuration
 logging.getLogger().setLevel(app.config['LOG_LEVEL'])

packet/git.py

@@ -0,0 +1,49 @@
+import json
+import os
+import subprocess
+
+def get_short_sha(commit_ish: str = 'HEAD'):
+    """
+    Get the short hash of a commit-ish
+    Returns '' if unfound
+    """
+
+    try:
+        rev_parse = subprocess.run(f'git rev-parse --short {commit_ish}'.split(), capture_output=True, check=True)
+        return rev_parse.stdout.decode('utf-8').strip()
+    except subprocess.CalledProcessError:
+        return ''
+
+def get_tag(commit_ish: str = 'HEAD'):
+    """
+    Get the name of the tag at a given commit-ish
+    Returns '' if untagged
+    """
+
+    try:
+        describe = subprocess.run(f'git describe --exact-match {commit_ish}'.split(), capture_output=True, check=True)
+        return describe.stdout.decode('utf-8').strip()
+    except subprocess.CalledProcessError:
+        return ''
+
+def get_version(commit_ish: str = 'HEAD'):
+    """
+    Get the version string of a commit-ish
+
+    If we have a commit and the commit is tagged, version is `tag (commit-sha)`
+    If we have a commit but not a tag, version is `commit-sha`
+    If we have neither, version is the version field of package.json
+    """
+
+    if sha := get_short_sha(commit_ish):
+        if tag := get_tag(commit_ish):
+            return f'{tag} ({sha})'
+        else:
+            return sha
+    else:
+        root_dir = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
+        with open(os.path.join(root_dir, 'package.json')) as package_file:
+            return json.load(package_file)['version']
+
+if __name__ == '__main__':
+    print(get_version())