new container images for minimal alpine runtime

for this commit, image sizes:
debian = 812.08 MB
alpine = 647.28 MB
alpine-slim-terraform = 209.72 MB
alpine-slim-tofu = 204.51 MB

Author: cazlo

.github/workflows/atlantis-image.yml

@@ -57,7 +57,7 @@ jobs:
       attestations: write
     strategy:
       matrix:
-        image_type: [alpine, debian]
+        image_type: [alpine, alpine-slim-terraform, alpine-slim-tofu, debian]
     runs-on: ubuntu-24.04
     env:
       # Set docker repo to either the fork or the main repo where the branch exists
@@ -202,7 +202,7 @@ jobs:
     runs-on: ubuntu-24.04
     strategy:
       matrix:
-        image_type: [alpine, debian]
+        image_type: [alpine, alpine-slim-terraform, alpine-slim-tofu, debian]
         platform: [linux/arm64/v8, linux/amd64, linux/arm/v7]
     env:
       # Set docker repo to either the fork or the main repo where the branch exists
@@ -251,7 +251,7 @@ jobs:
     name: Build Image
     strategy:
       matrix:
-        image_type: [alpine, debian]
+        image_type: [alpine, alpine-slim-terraform, alpine-slim-tofu, debian]
     runs-on: ubuntu-24.04
     steps:
       - name: Harden Runner

Dockerfile

@@ -135,7 +135,7 @@ RUN ./download-release.sh \
 
 # Stage 2 - Alpine
 # Creating the individual distro builds using targets
-FROM alpine:${ALPINE_TAG} AS alpine
+FROM alpine:${ALPINE_TAG} AS alpine-base
 
 EXPOSE ${ATLANTIS_PORT:-4141}
 
@@ -150,9 +150,6 @@ RUN addgroup atlantis && \
 
 # copy atlantis binary
 COPY --from=builder /app/atlantis /usr/local/bin/atlantis
-# copy terraform binaries
-COPY --from=deps /usr/local/bin/terraform/terraform* /usr/local/bin/
-COPY --from=deps /usr/local/bin/tofu/tofu* /usr/local/bin/
 # copy dependencies
 COPY --from=deps /usr/local/bin/conftest /usr/local/bin/conftest
 COPY --from=deps /usr/bin/git-lfs /usr/bin/git-lfs
@@ -179,6 +176,17 @@ USER atlantis
 ENTRYPOINT ["docker-entrypoint.sh"]
 CMD ["server"]
 
+FROM alpine-base as alpine
+# copy terraform binaries
+COPY --from=deps /usr/local/bin/terraform/terraform* /usr/local/bin/
+COPY --from=deps /usr/local/bin/tofu/tofu* /usr/local/bin/
+
+FROM alpine-base as alpine-slim-terraform
+COPY --from=deps /usr/local/bin/terraform/terraform /usr/local/bin/terraform
+
+FROM alpine-base as alpine-slim-tofu
+COPY --from=deps /usr/local/bin/tofu/tofu /usr/local/bin/tofu
+
 # Stage 2 - Debian
 FROM debian-base AS debian
 

Makefile

@@ -82,6 +82,20 @@ docker/dev: ## Build dev Dockerfile as atlantis-dev
 	GOOS=linux GOARCH=amd64 go build -o atlantis .
 	docker build -f Dockerfile.dev -t atlantis-dev .
 
+ALPINE_MINIMAL_VARIANT := terraform
+.PHONY: docker/alpine-slim
+docker/alpine-slim: ## Build slim terraform or tofu images
+	docker build --target alpine-slim-$(ALPINE_MINIMAL_VARIANT) -f Dockerfile -t localhost/$(IMAGE_NAME):latest-alpine-slim-$(ALPINE_MINIMAL_VARIANT) .
+
+.PHONY: docker/alpine
+docker/alpine: ## Build Dockerfile for alpine runtime target
+	docker build --target alpine -f Dockerfile -t localhost/$(IMAGE_NAME):latest-alpine .
+
+.PHONY: docker/debian
+docker/debian: ## Build Dockerfile for debian runtime target
+	docker build --target debian -f Dockerfile -t localhost/$(IMAGE_NAME):latest-debian .
+
+
 .PHONY: release
 release: ## Create packages for a release
 	docker run -v $$(pwd):/go/src/github.com/runatlantis/atlantis cimg/go:1.20 sh -c 'cd /go/src/github.com/runatlantis/atlantis && scripts/binary-release.sh'