add Dockerfile, refs #25

Dockerfile

@@ -0,0 +1,32 @@
+################################
+# STEP 1 build executable binary
+################################
+FROM golang:1.12.5-alpine3.9 AS builder
+LABEL stage=intermediate
+
+# Install git, required for fetching the dependencies.
+RUN apk update && apk add --no-cache git make
+
+WORKDIR /app
+COPY . .
+
+# Fetch dependencies, using go get, download only, verbose.
+RUN go get -d -v
+
+# Build the binary.
+RUN make esbulk
+
+############################
+# STEP 2 build a small image
+############################
+FROM scratch
+
+# Copy our static executable.
+COPY --from=builder /app/esbulk /app/esbulk
+
+# https://stackoverflow.com/questions/52969195/docker-container-running-golang-http-client-getting-error-certificate-signed-by
+COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
+
+# Default command.
+ENTRYPOINT ["/app/esbulk"]
+

Makefile

@@ -1,5 +1,5 @@
-SHELL := /bin/bash
 TARGETS = esbulk
+VERSION = 0.5.2
 
 # http://docs.travis-ci.com/user/languages/go/#Default-Test-Script
 test:
@@ -31,10 +31,17 @@ cover:
 	go tool cover -html=coverage.out
 
 esbulk:
-	go build cmd/esbulk/esbulk.go
+	CGO_ENABLED=0 go build cmd/esbulk/esbulk.go
 
 # ==== packaging
 
+image:
+	DOCKER_CONTENT_TRUST=0 docker build --rm -t esbulk:$(VERSION) .
+	docker rmi -f $$(docker images -q --filter label=stage=intermediate)
+
+rmi:
+	docker rmi esbulk:$(VERSION)
+
 deb: $(TARGETS)
 	mkdir -p packaging/debian/esbulk/usr/sbin
 	cp $(TARGETS) packaging/debian/esbulk/usr/sbin

README.md

@@ -38,11 +38,26 @@ For `deb` or `rpm` packages, see: https://github.com/miku/esbulk/releases
 [intenthq/esbulk-docker](https://hub.docker.com/r/intenthq/esbulk-docker/) as
 well (thanks [@albertpastrana](https://github.com/albertpastrana)), [#25](https://github.com/miku/esbulk/issues/25).
 
+Run:
+
 ```
-$ docker run -it intenthq/esbulk-docker esbulk -v
+$ docker run -it --rm intenthq/esbulk-docker esbulk -v
 0.5.1
 ```
 
+Since 0.5.2 (May 2019) there is a [Dockerfile](Dockerfile) included in the
+repo, it uses the multi-stage build and a FROM SCRATCH image, which allows for
+a lightweight 7.85MB image.
+
+```
+$ git clone https://github.com/miku/esbulk.git
+$ cd esbulk
+$ make image # use make rmi to cleanup
+$ docker run -it esbulk:0.5.2 -v
+0.5.2
+```
+
+
 Usage
 -----