From 037d4662c8e42cc5deadfec24dfe0e20ecc7b349 Mon Sep 17 00:00:00 2001
From: Colin Walters <walters@verbum.org>
Date: Mon, 11 Mar 2019 19:19:11 +0000
Subject: [PATCH] rhcos: Support channels

The code was hardcoded to `DefaultChannel`; add an environment variable
so people (and CI) can use the other channels.
---
 pkg/asset/rhcos/image.go |  4 ++--
 pkg/rhcos/ami.go         |  4 ++--
 pkg/rhcos/builds.go      | 13 ++++++++++++-
 pkg/rhcos/qemu.go        |  6 +++---
 4 files changed, 19 insertions(+), 8 deletions(-)

diff --git a/pkg/asset/rhcos/image.go b/pkg/asset/rhcos/image.go
index 956b85bc320..ab082524e77 100644
--- a/pkg/asset/rhcos/image.go
+++ b/pkg/asset/rhcos/image.go
@@ -55,9 +55,9 @@ func (i *Image) Generate(p asset.Parents) error {
 	defer cancel()
 	switch config.Platform.Name() {
 	case aws.Name:
-		osimage, err = rhcos.AMI(ctx, rhcos.DefaultChannel, config.Platform.AWS.Region)
+		osimage, err = rhcos.AMI(ctx, config.Platform.AWS.Region)
 	case libvirt.Name:
-		osimage, err = rhcos.QEMU(ctx, rhcos.DefaultChannel)
+		osimage, err = rhcos.QEMU(ctx)
 	case openstack.Name:
 		osimage = "rhcos"
 	case none.Name:
diff --git a/pkg/rhcos/ami.go b/pkg/rhcos/ami.go
index ee43dba5f89..335b78af87b 100644
--- a/pkg/rhcos/ami.go
+++ b/pkg/rhcos/ami.go
@@ -7,8 +7,8 @@ import (
 )
 
 // AMI fetches the HVM AMI ID of the latest Red Hat Enterprise Linux CoreOS release.
-func AMI(ctx context.Context, channel, region string) (string, error) {
-	meta, err := fetchLatestMetadata(ctx, channel)
+func AMI(ctx context.Context, region string) (string, error) {
+	meta, err := fetchLatestMetadata(ctx)
 	if err != nil {
 		return "", errors.Wrap(err, "failed to fetch RHCOS metadata")
 	}
diff --git a/pkg/rhcos/builds.go b/pkg/rhcos/builds.go
index 015b50ef615..5d4fd60b9a8 100644
--- a/pkg/rhcos/builds.go
+++ b/pkg/rhcos/builds.go
@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"io/ioutil"
 	"net/http"
+	"os"
 
 	"github.com/pkg/errors"
 	"github.com/sirupsen/logrus"
@@ -22,6 +23,15 @@ var (
 	baseURL = "https://releases-rhcos.svc.ci.openshift.org/storage/releases"
 )
 
+// getChannel returns a named "channel" which is just a subdirectory with
+// builds.json as defined by coreos-assembler
+func getChannel() string {
+	if channel, ok := os.LookupEnv("OPENSHIFT_INSTALL_OS_CHANNEL"); ok && channel != "" {
+		return channel
+	}
+	return DefaultChannel
+}
+
 type metadata struct {
 	AMIs []struct {
 		HVM  string `json:"hvm"`
@@ -36,9 +46,10 @@ type metadata struct {
 	OSTreeVersion string `json:"ostree-version"`
 }
 
-func fetchLatestMetadata(ctx context.Context, channel string) (metadata, error) {
+func fetchLatestMetadata(ctx context.Context) (metadata, error) {
 	build := buildName
 	var err error
+	channel := getChannel()
 	if build == "" {
 		build, err = fetchLatestBuild(ctx, channel)
 		if err != nil {
diff --git a/pkg/rhcos/qemu.go b/pkg/rhcos/qemu.go
index 98b0d33e88b..3c97fc38457 100644
--- a/pkg/rhcos/qemu.go
+++ b/pkg/rhcos/qemu.go
@@ -8,11 +8,11 @@ import (
 )
 
 // QEMU fetches the URL of the latest Red Hat Enterprise Linux CoreOS release.
-func QEMU(ctx context.Context, channel string) (string, error) {
-	meta, err := fetchLatestMetadata(ctx, channel)
+func QEMU(ctx context.Context) (string, error) {
+	meta, err := fetchLatestMetadata(ctx)
 	if err != nil {
 		return "", errors.Wrap(err, "failed to fetch RHCOS metadata")
 	}
 
-	return fmt.Sprintf("%s/%s/%s/%s", baseURL, channel, meta.OSTreeVersion, meta.Images.QEMU.Path), nil
+	return fmt.Sprintf("%s/%s/%s/%s", baseURL, getChannel(), meta.OSTreeVersion, meta.Images.QEMU.Path), nil
 }