Dockerfile: use GO_VERSION build-arg for overriding Go version

This allows overriding the version of Go without making modifications in the
source code, which can be useful to test against multiple versions.

For example:

    make GO_VERSION=1.13beta1 shell

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

Dockerfile

@@ -25,8 +25,9 @@
 #
 
 ARG CROSS="false"
+ARG GO_VERSION=1.12.7
 
-FROM golang:1.12.7 AS base
+FROM golang:${GO_VERSION} AS base
 ARG APT_MIRROR
 RUN sed -ri "s/(httpredir|deb).debian.org/${APT_MIRROR:-deb.debian.org}/g" /etc/apt/sources.list \
  && sed -ri "s/(security).debian.org/${APT_MIRROR:-security.debian.org}/g" /etc/apt/sources.list

Dockerfile.e2e

@@ -1,4 +1,6 @@
-FROM golang:1.12.7-alpine as base
+ARG GO_VERSION=1.12.7
+
+FROM golang:${GO_VERSION}-alpine AS base
 
 RUN apk --no-cache add \
     bash \

Dockerfile.simple

@@ -5,7 +5,9 @@
 
 # This represents the bare minimum required to build and test Docker.
 
-FROM golang:1.12.7
+ARG GO_VERSION=1.12.7
+
+FROM golang:${GO_VERSION}
 
 # allow replacing httpredir or deb mirror
 ARG APT_MIRROR=deb.debian.org

Dockerfile.windows

@@ -165,10 +165,12 @@ FROM microsoft/windowsservercore
 # Use PowerShell as the default shell
 SHELL ["powershell", "-Command", "$ErrorActionPreference = 'Stop'; $ProgressPreference = 'SilentlyContinue';"]
 
+ARG GO_VERSION=1.12.7
+
 # Environment variable notes:
 #  - GO_VERSION must be consistent with 'Dockerfile' used by Linux.
 #  - FROM_DOCKERFILE is used for detection of building within a container.
-ENV GO_VERSION=1.12.7 `
+ENV GO_VERSION=${GO_VERSION} `
     GIT_VERSION=2.11.1 `
     GOPATH=C:\go `
     FROM_DOCKERFILE=1

Makefile

@@ -150,7 +150,7 @@ build: DOCKER_BUILD_ARGS += --build-arg=CROSS=$(DOCKER_CROSS)
 build: DOCKER_BUILDKIT ?= 1
 build: bundles
 	$(warning The docker client CLI has moved to github.com/docker/cli. For a dev-test cycle involving the CLI, run:${\n} DOCKER_CLI_PATH=/host/path/to/cli/binary make shell ${\n} then change the cli and compile into a binary at the same location.${\n})
-	DOCKER_BUILDKIT="${DOCKER_BUILDKIT}" docker build ${BUILD_APT_MIRROR} ${DOCKER_BUILD_ARGS} ${DOCKER_BUILD_OPTS} -t "$(DOCKER_IMAGE)" -f "$(DOCKERFILE)" .
+	DOCKER_BUILDKIT="${DOCKER_BUILDKIT}" docker build --build-arg=GO_VERSION ${BUILD_APT_MIRROR} ${DOCKER_BUILD_ARGS} ${DOCKER_BUILD_OPTS} -t "$(DOCKER_IMAGE)" -f "$(DOCKERFILE)" .
 
 bundles:
 	mkdir bundles

hack/ci/windows.ps1

@@ -453,7 +453,7 @@ Try {
         Write-Host  -ForegroundColor Cyan "`n`nINFO: Building the image from Dockerfile.windows at $(Get-Date)..."
         Write-Host
         $ErrorActionPreference = "SilentlyContinue"
-        $Duration=$(Measure-Command { docker build -t docker -f Dockerfile.windows . | Out-Host })
+        $Duration=$(Measure-Command { docker build --build-arg=GO_VERSION -t docker -f Dockerfile.windows . | Out-Host })
         $ErrorActionPreference = "Stop"
         if (-not($LastExitCode -eq 0)) {
            Throw "ERROR: Failed to build image from Dockerfile.windows"