chore: refactor to multi-stage Dockerfile

Author: SkylerMalinowski

build/Dockerfile.operator Dockerfilebuild/Dockerfile.operator renamed to Dockerfile

@@ -21,20 +21,22 @@ COPY cmd/ cmd/
 COPY internal/ internal/
 
 # Build
-# the GOARCH has not a default value to allow the binary be built according to the host where the command
-# was called. For example, if we call make docker-build in a local env which has the Apple Silicon M1 SO
-# the docker BUILDPLATFORM arg will be linux/arm64 when for Apple x86 it will be linux/amd64. Therefore,
-# by leaving it empty we can ensure that the container and binary shipped on it will have the same platform.
-RUN CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -a -o manager cmd/manager/main.go
+RUN CGO_ENABLED=0 GOOS=${TARGETOS:-linux} GOARCH=${TARGETARCH} go build -o /workspace ./...
 
 ################################################################################
 
-# Use distroless as minimal base image to package the manager binary
-# Refer to https://github.com/GoogleContainerTools/distroless for more details
-FROM gcr.io/distroless/static:nonroot
-
+# Ref: https://github.com/GoogleContainerTools/distroless
+FROM gcr.io/distroless/static:nonroot AS manager
 WORKDIR /
 COPY --from=builder /workspace/manager .
 USER 65532:65532
-
 ENTRYPOINT ["/manager"]
+
+################################################################################
+
+# Ref: https://github.com/GoogleContainerTools/distroless
+FROM gcr.io/distroless/static:nonroot AS webhook
+WORKDIR /
+COPY --from=builder /workspace/webhook .
+USER 65532:65532
+ENTRYPOINT ["/webhook"]

build/Dockerfile.webhook

@@ -47,7 +47,8 @@ group "default" {
 
 target "operator" {
   inherits = ["_common"]
-  dockerfile = "build/Dockerfile.operator"
+  dockerfile = "Dockerfile"
+  target = "manager"
   labels = {
     # Ref: https://github.com/opencontainers/image-spec/blob/v1.0/annotations.md
     "org.opencontainers.image.title" = "Slurm Operator"
@@ -66,7 +67,8 @@ target "operator" {
 
 target "webhook" {
   inherits = ["_common"]
-  dockerfile = "build/Dockerfile.webhook"
+  dockerfile = "Dockerfile"
+  target = "webhook"
   labels = {
     # Ref: https://github.com/opencontainers/image-spec/blob/v1.0/annotations.md
     "org.opencontainers.image.title" = "Slurm Operator Webhook"

docker-bake.hcl

@@ -12,11 +12,13 @@ profiles:
         - image: slinky.slurm.net/slurm-operator
           context: ../../
           docker:
-            dockerfile: ./build/Dockerfile.operator
+            dockerfile: Dockerfile
+            target: manager
         - image: slinky.slurm.net/slurm-operator-webhook
           context: ../../
           docker:
-            dockerfile: ./build/Dockerfile.webhook
+            dockerfile: Dockerfile
+            target: webhook
     deploy:
       helm:
         releases: