*: add dockerfile

Dockerfile

+FROM alpine:latest
+
+MAINTAINER Eric Chiang <eric.chiang@coreos.com>
+
+RUN apk add --update ca-certificates 
+
+COPY bin/poke /poke
+
+ENTRYPOINT ["/poke"]
+
+CMD ["version"]

Makefile

@@ -3,11 +3,16 @@ ORG_PATH=github.com/coreos
 REPO_PATH=$(ORG_PATH)/$(PROJ)
 export PATH := $(PWD)/bin:$(PATH)
 
+VERSION=$(shell ./scripts/git-version)
+
+DOCKER_REPO=quay.io/ericchiang/poke
+DOCKER_IMAGE=$(DOCKER_REPO):$(VERSION)
+
 export GOBIN=$(PWD)/bin
 export GO15VENDOREXPERIMENT=1
 export CGO_ENABLED:=0
 
-LD_FLAGS="-w -X $(REPO_PATH)/version.Version=$(shell ./scripts/git-version)"
+LD_FLAGS="-w -X $(REPO_PATH)/version.Version=$(VERSION)"
 
 GOOS=$(shell go env GOOS)
 GOARCH=$(shell go env GOARCH)
@@ -37,6 +42,16 @@ lint:
       golint $$package; \
 	done
 
+.PHONY: docker-build
+docker-build: bin/poke
+	@docker build -t $(DOCKER_IMAGE) .
+
+.PHONY: docker-push
+docker-push: docker-build
+	@docker tag $(DOCKER_IMAGE) $(DOCKER_REPO):latest
+	@docker push $(DOCKER_IMAGE)
+	@docker push $(DOCKER_REPO):latest
+
 clean:
 	@rm bin/*