feat(image): add "slim" variant of minimal-size image, with statically-compiled binary

Dockerfile

@@ -18,6 +18,25 @@ WORKDIR /go/src/$REPOSITORY/$ARTIFACT
 # Build the binary
 RUN make
 
+#########################################
+# "slim" Distribution stage
+#########################################
+FROM alpine:latest AS slim
+
+# Repository location
+ARG REPOSITORY=github.com/ncarlier
+
+# Artifact name
+ARG ARTIFACT=webhookd
+
+# Install binary *only*
+COPY --from=builder /go/src/$REPOSITORY/$ARTIFACT/release/$ARTIFACT /usr/local/bin/$ARTIFACT
+
+VOLUME [ "/scripts" ]
+EXPOSE 8080
+
+CMD [ "webhookd" ]
+
 #########################################
 # Distribution stage
 #########################################

Makefile

@@ -46,7 +46,7 @@ clean:
 build:
 	-mkdir -p release
 	echo "Building: $(EXECUTABLE) $(VERSION) for $(GOOS)-$(GOARCH) ..."
-	GOOS=$(GOOS) GOARCH=$(GOARCH) go build -ldflags "$(LDFLAGS)" -o release/$(EXECUTABLE)
+	GOOS=$(GOOS) GOARCH=$(GOARCH) CGO_ENABLED=0 go build -tags netgo -ldflags "$(LDFLAGS)" -o release/$(EXECUTABLE)
 .PHONY: build
 
 release/$(EXECUTABLE): build
@@ -68,6 +68,12 @@ image:
 	docker build --rm -t ncarlier/$(APPNAME) .
 .PHONY: image
 
+## Create "slim" Docker image
+image-slim:
+	echo "Building slim Docker image ..."
+	docker build --rm --target slim -t ncarlier/$(APPNAME)-slim .
+.PHONY: image
+
 ## Generate changelog
 changelog:
 	standard-changelog --first-release