Build a docker container

The build phase makes the assumption that any capnproto-files
are pre-processed before building in-docker.

Dockerfile

@@ -0,0 +1,17 @@
+FROM golang:1.12-alpine as builder
+
+WORKDIR /go/src/github.com/cloudflare/cloudflared/
+COPY . .
+
+RUN apk add --no-cache gcc musl-dev git upx ca-certificates
+RUN VERSION=$(git describe --tags --always --dirty="-dev") && \
+    DATE=$(date -u '+%Y-%m-%dT%H:%MZ') && \
+    go build -ldflags "-X main.Version=\"${VERSION}\" -X main.BuildTime=\"${DATE}\"" \
+             -installsuffix cgo -o cloudflared ./cmd/cloudflared
+RUN upx --no-progress cloudflared
+
+FROM alpine:3.9
+COPY --from=builder /go/src/github.com/cloudflare/cloudflared/cloudflared /usr/local/bin/
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/ca-certificates.crt
+ENTRYPOINT ["cloudflared"]
+CMD ["version"]

Makefile

@@ -31,6 +31,10 @@ clean:
 cloudflared: tunnel-deps
 	go build -v $(VERSION_FLAGS) $(IMPORT_PATH)/cmd/cloudflared
 
+.PHONY: container
+container:
+	docker build -t cloudflare/cloudflared:"$(VERSION)" .
+
 .PHONY: test
 test: vet
 	go test -v -race $(VERSION_FLAGS) ./...