Move COPY in Dockerfile and add build script.

COPY in the Dockerfile has been moved so that changes to the source code
do not cause an apt update unnecessarily.
A build script has aslo been added to build and extract the build artefacts.
This build script is usedby Ansible to deploy the application to compute hosts.

Change-Id: I66d2b671d991d1ce3bef544532b058d33f32d282

Create build script which exports the build artefacts

Change-Id: Ifa1458a6b17484d378ec14b4cba2e0493b722f7b

Make build script fail if any of the stages fail

Change-Id: I325cf2d44f40f19a198bc03858625add20e10494

.gitignore

@@ -1,2 +1,4 @@
 .tox
 doc/build
+
+libvirtd_exporter

Dockerfile

@@ -1,9 +1,9 @@
 FROM golang:1.13.5 AS builder
 WORKDIR /go/src/app
-COPY . .
 RUN apt-get update && \
     apt-get -y install libvirt-dev && \
     apt-get clean all
+COPY . .
 RUN go build
 
 FROM golang:1.13.5

build.sh

@@ -0,0 +1,14 @@
+#!/bin/bash
+# Small script to build libvirtd-exporter using docker and export the resulting binary
+
+set -e
+docker build -t libvirtd-exporter .
+
+# Start container with result
+docker run  --entrypoint sh -itd --name libvirtd-exporter libvirtd-exporter
+
+# Extract build atifact to host
+docker cp libvirtd-exporter:/libvirtd_exporter .
+
+docker stop libvirtd-exporter
+docker rm -f libvirtd-exporter