*: provide a default OS image for libvirt

Instead of requiring the user to download RHCOS and unpack it, this
allows them to be lazy and just let the installer download the image
from a default location. Note that there is no caching, so it is
recommended that users still manually download and unpack RHCOS.

Documentation/dev/libvirt-howto.md

@@ -16,7 +16,9 @@ git clone https://github.com/openshift/installer.git
 cd installer
 ```
 
-#### 1.3 Download and prepare the operating system image
+#### 1.3 (Optional) Download and prepare the operating system image
+
+*By default, the installer will download the latest RHCOS image every time it is invoked. This may be problematic for users who create a large number of clusters or who have limited network bandwidth. The installer allows a local image to be used instead.*
 
 Download the latest RHCOS image (you will need access to the Red Hat internal build systems):
 
@@ -85,14 +87,14 @@ iptables -I INPUT -p tcp -s 192.168.124.0/24 -d 192.168.124.1 --dport 16509 \
 
 #### 1.7 Prepare the configuration file
 1. `cp examples/libvirt.yaml ./`
-1. Edit the configuration file:
+2. Edit the configuration file:
     1. Set an email and password in the `admin` section
-    1. Set a `baseDomain` (to `tt.testing`)
-    1. Set the `sshKey` in the `admin` section to the **contents** of an ssh key (e.g. `ssh-rsa AAAA...`)
-    1. Set the `imagePath` to the **absolute** path of the operating system image you downloaded
-    1. Set the `name` (e.g. test1)
-    1. Look at the `podCIDR` and `serviceCIDR` fields in the `networking` section. Make sure they don't conflict with anything important.
-    1. Set the `pullSecret` to your JSON pull secret.
+    2. Set a `baseDomain` (to `tt.testing`)
+    3. Set the `sshKey` in the `admin` section to the **contents** of an ssh key (e.g. `ssh-rsa AAAA...`)
+    4. Set the `name` (e.g. test1)
+    5. Look at the `podCIDR` and `serviceCIDR` fields in the `networking` section. Make sure they don't conflict with anything important.
+    6. Set the `pullSecret` to your JSON pull secret.
+    7. (Optional) Change the `image` to the file URL of the operating system image you downloaded (e.g. `file:///home/user/Downloads/rhcos.qcow`). This will allow the installer to re-use that image instead of having to download it every time.
 
 #### 1.8 Set up NetworkManager DNS overlay
 This step is optional, but useful for being able to resolve cluster-internal hostnames from your host.

examples/libvirt.yaml

@@ -19,7 +19,7 @@ libvirt:
     name: tectonic
     ifName: tt0
     ipRange: 192.168.124.0/24
-  imagePath: /path/to/image
+  image: http://aos-ostree.rhev-ci-vms.eng.rdu2.redhat.com/rhcos/images/cloud/latest/rhcos-qemu.qcow2.gz
 
 ca:
   # (optional) The content of the PEM-encoded CA certificate, used to generate Tectonic Console's server certificate.

installer/pkg/config-generator/generator.go

@@ -248,10 +248,12 @@ func (c *ConfigGenerator) installConfig() (*types.InstallConfig, error) {
 			},
 		}
 		masterPlatform.Libvirt = &types.LibvirtMachinePoolPlatform{
-			QCOWImagePath: c.Libvirt.QCOWImagePath,
+			ImagePool:   "default",
+			ImageVolume: "coreos_base",
 		}
 		workerPlatform.Libvirt = &types.LibvirtMachinePoolPlatform{
-			QCOWImagePath: c.Libvirt.QCOWImagePath,
+			ImagePool:   "default",
+			ImageVolume: "coreos_base",
 		}
 	default:
 		return nil, fmt.Errorf("installconfig: invalid platform %s", c.Platform)

installer/pkg/config/libvirt/libvirt.go

@@ -14,12 +14,12 @@ const (
 
 // Libvirt encompasses configuration specific to libvirt.
 type Libvirt struct {
-	URI           string `json:"tectonic_libvirt_uri,omitempty" yaml:"uri"`
-	QCOWImagePath string `json:"tectonic_coreos_qcow_path,omitempty" yaml:"imagePath"`
-	Network       `json:",inline" yaml:"network"`
-	MasterIPs     []string `json:"tectonic_libvirt_master_ips,omitempty" yaml:"masterIPs"`
-	WorkerIPs     []string `json:"tectonic_libvirt_worker_ips,omitempty" yaml:"workerIPs"`
-	BootstrapIP   string   `json:"tectonic_libvirt_bootstrap_ip,omitempty" yaml:"bootstrapIP"`
+	URI         string `json:"tectonic_libvirt_uri,omitempty" yaml:"uri"`
+	Image       string `json:"tectonic_os_image,omitempty" yaml:"image"`
+	Network     `json:",inline" yaml:"network"`
+	MasterIPs   []string `json:"tectonic_libvirt_master_ips,omitempty" yaml:"masterIPs"`
+	WorkerIPs   []string `json:"tectonic_libvirt_worker_ips,omitempty" yaml:"workerIPs"`
+	BootstrapIP string   `json:"tectonic_libvirt_bootstrap_ip,omitempty" yaml:"bootstrapIP"`
 }
 
 // Network describes a libvirt network configuration.

installer/pkg/config/validate.go

@@ -19,10 +19,6 @@ const (
 	maxS3BucketNameLength = 63
 )
 
-var (
-	qcowMagic = []byte{'Q', 'F', 'I', 0xfb}
-)
-
 // ErrUnmatchedNodePool is returned when a nodePool was specified but not found in the nodePools list.
 type ErrUnmatchedNodePool struct {
 	name string
@@ -160,9 +156,6 @@ func (c *Cluster) validateLibvirt() []error {
 	if err := validate.PrefixError("libvirt uri", validate.NonEmpty(c.Libvirt.URI)); err != nil {
 		errs = append(errs, err)
 	}
-	if err := validate.PrefixError("libvirt imagePath is not a valid QCOW image", validate.FileHeader(c.Libvirt.QCOWImagePath, qcowMagic)); err != nil {
-		errs = append(errs, err)
-	}
 	if err := validate.PrefixError("libvirt network name", validate.NonEmpty(c.Libvirt.Network.Name)); err != nil {
 		errs = append(errs, err)
 	}

installer/pkg/config/validate_test.go

@@ -1,7 +1,6 @@
 package config
 
 import (
-	"io/ioutil"
 	"os"
 	"testing"
 
@@ -444,21 +443,6 @@ func TestValidateIgnitionFiles(t *testing.T) {
 }
 
 func TestValidateLibvirt(t *testing.T) {
-	fValid, err := ioutil.TempFile("", "qcow")
-	if err != nil {
-		t.Fatalf("failed to create temporary file: %v", err)
-	}
-	if _, err := fValid.Write(qcowMagic); err != nil {
-		t.Fatalf("failed to write to temporary file: %v", err)
-	}
-	fValid.Close()
-	defer os.Remove(fValid.Name())
-	fInvalid, err := ioutil.TempFile("", "qcow")
-	if err != nil {
-		t.Fatalf("failed to create temporary file: %v", err)
-	}
-	fInvalid.Close()
-	defer os.Remove(fInvalid.Name())
 	cases := []struct {
 		cluster Cluster
 		err     bool
@@ -474,24 +458,9 @@ func TestValidateLibvirt(t *testing.T) {
 		{
 			cluster: Cluster{
 				Libvirt: libvirt.Libvirt{
-					Network:       libvirt.Network{},
-					QCOWImagePath: "",
-					URI:           "",
-				},
-				Networking: defaultCluster.Networking,
-			},
-			err: true,
-		},
-		{
-			cluster: Cluster{
-				Libvirt: libvirt.Libvirt{
-					Network: libvirt.Network{
-						Name:    "tectonic",
-						IfName:  libvirt.DefaultIfName,
-						IPRange: "10.0.1.0/24",
-					},
-					QCOWImagePath: fInvalid.Name(),
-					URI:           "baz",
+					Network: libvirt.Network{},
+					Image:   "",
+					URI:     "",
 				},
 				Networking: defaultCluster.Networking,
 			},
@@ -505,8 +474,8 @@ func TestValidateLibvirt(t *testing.T) {
 						IfName:  libvirt.DefaultIfName,
 						IPRange: "10.0.1.0/24",
 					},
-					QCOWImagePath: fValid.Name(),
-					URI:           "baz",
+					Image: "file:///foo",
+					URI:   "baz",
 				},
 				Networking: defaultCluster.Networking,
 			},
@@ -520,8 +489,8 @@ func TestValidateLibvirt(t *testing.T) {
 						IfName:  libvirt.DefaultIfName,
 						IPRange: "10.2.1.0/24",
 					},
-					QCOWImagePath: fValid.Name(),
-					URI:           "baz",
+					Image: "file:///foo",
+					URI:   "baz",
 				},
 				Networking: defaultCluster.Networking,
 			},
@@ -535,8 +504,8 @@ func TestValidateLibvirt(t *testing.T) {
 						IfName:  libvirt.DefaultIfName,
 						IPRange: "x",
 					},
-					QCOWImagePath: "foo",
-					URI:           "baz",
+					Image: "file:///foo",
+					URI:   "baz",
 				},
 				Networking: defaultCluster.Networking,
 			},
@@ -550,12 +519,12 @@ func TestValidateLibvirt(t *testing.T) {
 						IfName:  libvirt.DefaultIfName,
 						IPRange: "192.168.0.1/24",
 					},
-					QCOWImagePath: "foo",
-					URI:           "baz",
+					Image: "file:///foo",
+					URI:   "baz",
 				},
 				Networking: defaultCluster.Networking,
 			},
-			err: true,
+			err: false,
 		},
 	}
 

installer/pkg/validate/validate.go

@@ -1,7 +1,6 @@
 package validate
 
 import (
-	"bytes"
 	"crypto/x509"
 	"encoding/json"
 	"encoding/pem"
@@ -469,19 +468,3 @@ func lastIP(cidr *net.IPNet) net.IP {
 	}
 	return last
 }
-
-// FileHeader validates that the file at the specified path begins with the given string.
-func FileHeader(path string, header []byte) error {
-	f, err := os.Open(path)
-	if err != nil {
-		return err
-	}
-	buf := make([]byte, len(header))
-	if _, err := f.Read(buf); err != nil {
-		return err
-	}
-	if !bytes.Equal(buf, header) {
-		return fmt.Errorf("file %q does not begin with %q", path, string(header))
-	}
-	return nil
-}

installer/pkg/validate/validate_test.go

@@ -610,52 +610,3 @@ func TestFileExists(t *testing.T) {
 		}
 	}
 }
-
-func TestFileHeader(t *testing.T) {
-	cases := []struct {
-		actual   []byte
-		expected []byte
-		err      bool
-	}{
-		{
-			actual:   []byte{},
-			expected: []byte("foo"),
-			err:      true,
-		},
-		{
-			actual:   []byte("foo"),
-			expected: []byte("bar"),
-			err:      true,
-		},
-		{
-			actual:   []byte("fooooo"),
-			expected: []byte("foo"),
-			err:      false,
-		},
-		{
-			actual:   []byte("fooooo"),
-			expected: []byte{},
-			err:      false,
-		},
-	}
-
-	for i, c := range cases {
-		f, err := ioutil.TempFile("", "fileheader")
-		if err != nil {
-			t.Errorf("test case %d: failed to create temporary file: %v", i, err)
-			continue
-		}
-		if _, err := f.Write(c.actual); err != nil {
-			t.Errorf("test case %d: failed to write to temporary file: %v", i, err)
-		}
-		f.Close()
-		if err := validate.FileHeader(f.Name(), c.expected); (err != nil) != c.err {
-			no := "no"
-			if c.err {
-				no = "an"
-			}
-			t.Errorf("test case %d: expected %s error, got %v", i, no, err)
-		}
-		os.Remove(f.Name())
-	}
-}

modules/libvirt/volume/main.tf

@@ -1,5 +1,4 @@
-# Create a QCOW volume from the downloaded path
 resource "libvirt_volume" "coreos_base" {
   name   = "coreos_base"
-  source = "file://${var.coreos_qcow_path}"
+  source = "file://${var.image}"
 }

modules/libvirt/volume/variables.tf

@@ -1,4 +1,4 @@
-variable "coreos_qcow_path" {
-  description = "The path on disk to the coreos disk image"
+variable "image" {
+  description = "The URL of the OS disk image"
   type        = "string"
 }

pkg/types/machinepools.go

@@ -50,6 +50,10 @@ type EC2RootVolume struct {
 // LibvirtMachinePoolPlatform stores the configuration for a machine pool
 // installed on libvirt.
 type LibvirtMachinePoolPlatform struct {
-	// QCOWImagePath
-	QCOWImagePath string `json:"qcowImagePath"`
+	// ImagePool is the name of the libvirt storage pool to which the storage
+	// volume containing the OS image belongs.
+	ImagePool string `json:"imagePool"`
+	// ImageVolume is the name of the libvirt storage volume containing the OS
+	// image.
+	ImageVolume string `json:"imageVolume"`
 }

steps/infra/libvirt/main.tf

@@ -5,7 +5,7 @@ provider "libvirt" {
 module "libvirt_base_volume" {
   source = "../../../modules/libvirt/volume"
 
-  coreos_qcow_path = "${var.tectonic_coreos_qcow_path}"
+  image = "${var.tectonic_os_image}"
 }
 
 resource "libvirt_volume" "master" {

steps/variables-libvirt.tf

@@ -18,9 +18,9 @@ variable "tectonic_libvirt_ip_range" {
   description = "IP range for the libvirt machines"
 }
 
-variable "tectonic_coreos_qcow_path" {
+variable "tectonic_os_image" {
   type        = "string"
-  description = "path to a Red Hat CoreOS qcow image"
+  description = "The URL of the OS disk image"
 }
 
 variable "tectonic_libvirt_bootstrap_ip" {

tests/run.sh

@@ -101,7 +101,7 @@ python <<-EOF >"${CLUSTER_NAME}.yaml"
 	        config['aws']['master']['iamRoleName'] = 'tf-tectonic-master-node'
 	        config['aws']['worker']['iamRoleName'] = 'tf-tectonic-worker-node'
 	elif '${BACKEND}' == 'libvirt':
-	    config['libvirt']['imagePath'] = '${IMAGE_PATH}'
+	    config['libvirt']['image'] = 'file://${IMAGE_PATH}'
 	yaml.safe_dump(config, sys.stdout)
 	EOF