Display git commit sha in footer

Dockerfile

@@ -1,3 +1,12 @@
+FROM ubuntu:latest as git
+RUN apt-get update \
+    && apt-get install -y git \
+    && mkdir /app
+
+ADD . /app
+WORKDIR /app
+RUN git rev-parse HEAD | tee /version
+
 FROM python:3.8.5-slim
 
 RUN apt-get update \
@@ -13,6 +22,7 @@ COPY docker ./docker/
 COPY blog ./blog/
 COPY attachments ./attachments/
 COPY articles ./articles/
+COPY --from=git /version /app/.version
 
 ENV SECRET_KEY "changeme"
 ENV DEBUG "false"

articles/context_processors.py

@@ -21,3 +21,14 @@ def date_format(request):
     if request.path in IGNORED_PATHS:
         return {}
     return {"CUSTOM_ISO": r"Y-m-d\TH:i:sO"}
+
+
+def git_version(request):
+    if request.path in IGNORED_PATHS:
+        return {}
+    try:
+        with open("/app/.version") as f:
+            version = f.read().strip()[:8]
+    except FileNotFoundError:
+        version = "latest"
+    return {"git_version": version}

articles/templates/articles/base.html

@@ -49,7 +49,8 @@
         This blog and all articles by Gabriel Augendre are licensed under the
         <a href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA 4.0 International License</a>.
         Code blocks by Gabriel Augendre are licensed under the
-        <a href="https://www.gnu.org/licenses/gpl-3.0.html">GNU GENERAL PUBLIC LICENSE version 3</a>.
+        <a href="https://www.gnu.org/licenses/gpl-3.0.html">GNU GENERAL PUBLIC LICENSE version 3</a>.<br>
+        Currently deployed version: {{ git_version }}
     </p>
 </footer>
 </body>

blog/settings.py

@@ -99,6 +99,7 @@ TEMPLATES = [
                 "articles.context_processors.pages",
                 "articles.context_processors.drafts_count",
                 "articles.context_processors.date_format",
+                "articles.context_processors.git_version",
             ],
         },
     },