From 99db0017f82b23ce065dc98ab88da21a4f6d98d1 Mon Sep 17 00:00:00 2001
From: Julian Kornberger <jk+github@digineo.de>
Date: Mon, 28 Jan 2019 01:26:44 +0100
Subject: [PATCH] Update Dockerfile to use Go 1.11 with modules

---
 Dockerfile | 23 ++++++++++++++++-------
 1 file changed, 16 insertions(+), 7 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index bad4572..16f9a50 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,14 +1,23 @@
-FROM golang:1.8
-ADD . /go/src/github.com/kumina/postfix_exporter
-WORKDIR /go/src/github.com/kumina/postfix_exporter
+FROM golang:1.11 AS builder
+WORKDIR /src
+
+# avoid downloading the dependencies on succesive builds
 RUN apt-get update -qq && apt-get install -qqy \
   build-essential \
   libsystemd-dev
-RUN go get -v ./...
-RUN go build
+
+COPY go.mod go.sum ./
+RUN go mod download
+RUN go mod verify
+
+COPY . .
+
+# Force the go compiler to use modules
+ENV GO111MODULE=on
+RUN go build -o /bin/postfix_exporter
 
 FROM debian:latest
 EXPOSE 9154
 WORKDIR /
-COPY --from=0 /go/src/github.com/kumina/postfix_exporter/postfix_exporter .
-ENTRYPOINT ["/postfix_exporter"]
+COPY --from=builder /bin/postfix_exporter /bin/
+ENTRYPOINT ["/bin/postfix_exporter"]