From e3ca393d9e0219af0de3c0eba3cfba99de2fc41e Mon Sep 17 00:00:00 2001
From: Ian Howell <ian.howell0@gmail.com>
Date: Mon, 18 Nov 2019 15:55:02 -0600
Subject: [PATCH] Utilize Docker caching to speed up image building

This rearranges the Dockerfile to COPY over the go module files for
downloading prior to building, linting, and testing. This will allow
developers to more quickly test their code via Docker given that their
dependencies change infrequently.

Change-Id: I3650fbd9ca18d453921d25a536e8b4cf60ce1b5e
---
 Dockerfile | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index bcaaf44e1..13c8ac7a0 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -3,11 +3,13 @@ ARG RELEASE_IMAGE=scratch
 FROM ${GO_IMAGE} as builder
 
 SHELL [ "/bin/bash", "-cex" ]
-ADD . /usr/src/airshipctl
 WORKDIR /usr/src/airshipctl
 
-RUN make get-modules
+# Take advantage of caching for dependency acquisition
+COPY go.mod go.sum /usr/src/airshipctl/
+RUN go mod download
 
+COPY . /usr/src/airshipctl/
 ARG MAKE_TARGET=build
 RUN make ${MAKE_TARGET}