asset: add rhcos Image asset to generate image location

pkg/asset/rhcos/image.go

@@ -0,0 +1,72 @@
+// Package rhcos contains assets for RHCOS.
+package rhcos
+
+import (
+	"context"
+	"os"
+	"time"
+
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+
+	"github.com/openshift/installer/pkg/asset"
+	"github.com/openshift/installer/pkg/asset/installconfig"
+	"github.com/openshift/installer/pkg/rhcos"
+	"github.com/openshift/installer/pkg/types/aws"
+	"github.com/openshift/installer/pkg/types/libvirt"
+	"github.com/openshift/installer/pkg/types/none"
+	"github.com/openshift/installer/pkg/types/openstack"
+)
+
+// Image is location of RHCOS image.
+// This stores the location of the image based on the platform.
+// eg. on AWS this contains ami-id, on Livirt this can be the URI for QEMU image etc.
+type Image string
+
+var _ asset.Asset = (*Image)(nil)
+
+// Name returns the human-friendly name of the asset.
+func (i *Image) Name() string {
+	return "Image"
+}
+
+// Dependencies returns no dependencies.
+func (i *Image) Dependencies() []asset.Asset {
+	return []asset.Asset{
+		&installconfig.InstallConfig{},
+	}
+}
+
+// Generate the RHCOS image location.
+func (i *Image) Generate(p asset.Parents) error {
+	if oi, ok := os.LookupEnv("OPENSHIFT_INSTALL_OS_IMAGE_OVERRIDE"); ok && oi != "" {
+		logrus.Warn("Found override for OS Image. Please be warned, this is not advised")
+		*i = Image(oi)
+		return nil
+	}
+
+	ic := &installconfig.InstallConfig{}
+	p.Get(ic)
+	config := ic.Config
+
+	var osimage string
+	var err error
+	ctx, cancel := context.WithTimeout(context.TODO(), 30*time.Second)
+	defer cancel()
+	switch config.Platform.Name() {
+	case aws.Name:
+		osimage, err = rhcos.AMI(ctx, rhcos.DefaultChannel, config.Platform.AWS.Region)
+	case libvirt.Name:
+		osimage, err = rhcos.QEMU(ctx, rhcos.DefaultChannel)
+	case openstack.Name:
+		osimage = "rhcos"
+	case none.Name:
+	default:
+		return errors.New("invalid Platform")
+	}
+	if err != nil {
+		return err
+	}
+	*i = Image(osimage)
+	return nil
+}