Leaner Docker image through the use of multi-stage builds

.dockerignore

@@ -0,0 +1,6 @@
+README.md
+LICENSE
+Makefile
+dist/
+goreleaser.yml
+openapi/

.travis.yml

@@ -24,7 +24,6 @@ script:
   - docker build -t "$DOCKER_REPO" .
   - docker run -d --name stripe-mock-container -p 12111:12111 "$DOCKER_REPO"
   - docker ps -a
-  - docker exec -it stripe-mock-container /bin/sh -c "cd /go/src/github.com/stripe/stripe-mock/; go test ./..."
 
 deploy:
   provider: script

Dockerfile

@@ -1,9 +1,29 @@
-FROM golang:1.9-alpine
+# -*- mode: dockerfile -*-
+#
+# A multi-stage Dockerfile that builds a Linux target then creates a small
+# final image for deployment.
 
-ADD . /go/src/github.com/stripe/stripe-mock
+#
+# STAGE 1
+#
+# Uses a Go image to build a release binary.
+#
 
-RUN go install github.com/stripe/stripe-mock
+FROM golang:1.9-alpine AS builder
+WORKDIR /go/src/github.com/stripe/stripe-mock/
+ADD ./ ./
+RUN CGO_ENABLED=0 GOOS=linux go build -a -installsuffix cgo -o stripe-mock .
 
-EXPOSE 12111
+#
+# STAGE 2
+#
+# Use a tiny base image (alpine) and copy in the release target. This produces
+# a very small output image for deployment.
+#
 
-ENTRYPOINT /go/bin/stripe-mock
+FROM alpine:latest
+RUN apk --no-cache add ca-certificates
+WORKDIR /
+COPY --from=builder /go/src/github.com/stripe/stripe-mock/stripe-mock .
+ENTRYPOINT /stripe-mock
+EXPOSE 12111