Enhance Dockerfile adding multistage build

.goreleaser.yaml

@@ -26,7 +26,7 @@ release:
 dockers:
   - image_templates:
       - "ghcr.io/jetstack/dependency-track-exporter:{{.Version}}-amd64"
-    dockerfile: Dockerfile
+    dockerfile: Dockerfile.goreleaser
     use: buildx
     build_flag_templates:
       - "--pull"
@@ -38,7 +38,7 @@ dockers:
       - "--platform=linux/amd64"
   - image_templates:
       - "ghcr.io/jetstack/dependency-track-exporter:{{.Version}}-arm64"
-    dockerfile: Dockerfile
+    dockerfile: Dockerfile.goreleaser
     use: buildx
     build_flag_templates:
       - "--pull"

Dockerfile

@@ -1,6 +1,27 @@
+FROM golang:1.19-buster AS build
+
+WORKDIR /app
+
+COPY go.mod ./
+
+COPY go.sum ./
+
+RUN go mod download
+
+COPY *.go ./
+
+COPY internal ./internal
+
+RUN go build -o /dependency-track-exporter
+
 FROM gcr.io/distroless/static:nonroot
 
-COPY dependency-track-exporter /
+WORKDIR /
+
+COPY --from=build /dependency-track-exporter /dependency-track-exporter
+
+EXPOSE 9916
+
+USER nonroot:nonroot
 
-USER nonroot
-ENTRYPOINT ["/dependency-track-exporter"]
+ENTRYPOINT ["/dependency-track-exporter"]

Dockerfile.goreleaser

@@ -0,0 +1,7 @@
+FROM gcr.io/distroless/static:nonroot
+
+COPY dependency-track-exporter /
+
+USER nonroot
+
+ENTRYPOINT ["/dependency-track-exporter"]