Uses multi-stage builds to create images

follows along here loosely:

https://docs.docker.com/develop/develop-images/multistage-build/
https://blog.alexellis.io/mutli-stage-docker-builds/

.gitignore

@@ -0,0 +1 @@
+build

Dockerfile

@@ -0,0 +1,13 @@
+FROM golang:1.10.1 as build
+WORKDIR /go/src/mcquay.me/lim
+COPY . .
+RUN CGO_ENABLED=0 GOOS=linux go build -o /usr/local/bin/lim .
+
+FROM alpine:latest
+RUN apk --no-cache add ca-certificates
+
+WORKDIR /
+
+COPY --from=build /usr/local/bin/lim /bin/
+
+CMD ["/bin/sh", "-c", "cat /dev/urandom | /bin/lim 16b | xxd"]

Makefile

@@ -0,0 +1,20 @@
+GOFILES := $(shell find . -type f | grep go$$ )
+
+build/lim: build build/.docker-image ${GOFILES}
+	@echo "fetching binary from image"
+	@docker create --name ext smcquay/lim:latest > /dev/null
+	@docker cp ext:/bin/lim build/ > /dev/null
+	@docker rm -f ext > /dev/null
+	@touch build/lim
+
+build/.docker-image: ${GOFILES}
+	@echo "building docker image"
+	@docker build --no-cache -t smcquay/lim:latest . > /dev/null
+	@touch build/.docker-image
+
+build:
+	@mkdir build
+
+.PHONY: clean
+clean:
+	@rm -rf build