Fix commit resolution for Docker builds

.github/workflows/publish.yml

@@ -82,3 +82,4 @@ jobs:
           provenance: false
           # https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry#adding-a-description-to-multi-arch-images
           outputs: type=image,name=target,annotation-index.org.opencontainers.image.description=A multi-arch Docker image for the Maybe Rails app
+          build-args: BUILD_COMMIT_SHA=${{ github.sha }}

Dockerfile

@@ -9,13 +9,15 @@ WORKDIR /rails
 
 # Install base packages
 RUN apt-get update -qq && \
-    apt-get install --no-install-recommends -y curl libvips postgresql-client git
+    apt-get install --no-install-recommends -y curl libvips postgresql-client
 
 # Set production environment
+ARG BUILD_COMMIT_SHA
 ENV RAILS_ENV="production" \
     BUNDLE_DEPLOYMENT="1" \
     BUNDLE_PATH="/usr/local/bundle" \
-    BUNDLE_WITHOUT="development"
+    BUNDLE_WITHOUT="development" \
+    BUILD_COMMIT_SHA=${BUILD_COMMIT_SHA}
     
 # Throw-away build stage to reduce size of final image
 FROM base AS build

config/initializers/version.rb

@@ -5,8 +5,12 @@ module Maybe
     end
 
     def commit_sha
+      if Rails.env.production?
+        ENV["BUILD_COMMIT_SHA"]
+      else
         `git rev-parse HEAD`.chomp
       end
+    end
 
     private
       def semver