add build argument for commit SHA to Dockerfile and update deploy command in workflow

Author: kentcdodds

.github/workflows/validate.yml

@@ -76,7 +76,9 @@ jobs:
         uses: superfly/flyctl-actions/[email protected]
 
       - name: 🚀 Deploy
-        run: flyctl deploy --remote-only
+        run:
+          flyctl deploy --remote-only --build-arg EPICSHOP_COMMIT_SHA=${{
+          github.sha }}
         working-directory: ./epicshop
         env:
           FLY_API_TOKEN: ${{ secrets.FLY_API_TOKEN }}

epicshop/Dockerfile

@@ -11,10 +11,19 @@ ENV FLY="true"
 ENV PORT="8080"
 ENV NODE_ENV="production"
 
+# Build argument for commit SHA to bust cache when repo changes
+ARG EPICSHOP_COMMIT_SHA
+ENV EPICSHOP_COMMIT_SHA=${EPICSHOP_COMMIT_SHA}
+
 WORKDIR /myapp
 
 # Clone the workshop repo during build time, excluding database files
-RUN git clone --depth 1 ${EPICSHOP_GITHUB_REPO} ${EPICSHOP_CONTEXT_CWD}
+# Clone specific commit to keep image small while ensuring cache busting
+RUN git init ${EPICSHOP_CONTEXT_CWD} && \
+    cd ${EPICSHOP_CONTEXT_CWD} && \
+    git remote add origin ${EPICSHOP_GITHUB_REPO} && \
+    git fetch --depth 1 origin ${EPICSHOP_COMMIT_SHA} && \
+    git checkout ${EPICSHOP_COMMIT_SHA}
 
 ADD . .