Merge pull request #718 from Prashanth684/virtio-blk-multiarch

Use virtio-blk instead of disk for injecting ignition config for s390x and ppc64

examples/v0.12/coreos/README.md

@@ -11,7 +11,7 @@ with their own Ignition configuration
 
 
 ### Supported architectures
-This example will work on i686 (x86), x86\_64 (AMD64), aarch64 (ARM64), s390x (IBM Z) and IBM PowerPC. On i686, x86\_64, and aarch64, the Terraform provider uses QEMU's firmware configuration (fw\_cfg) device to pass the Ignition config through to the Ignition instance running in the virtual machine. In order for this to work, Ignition needs to be run with `--provider=qemu`. Unfortunately, QEMU doesn't support the firmware configuration device for s390x and PowerPC guests, so the Terraform provider falls back to using an OpenStack config-drive instead. The config-drive will automatically be created by the provider, provided that `mkisofs` is installed in the path, so no changes are necessary to the Terraform templates. Ignition needs to be run with `--provider=openstack` when inside of an s390x or PowerPc guest in order to find the config-drive.
+This example will work on i686 (x86), x86\_64 (AMD64), aarch64 (ARM64), s390x (IBM Z) and IBM PowerPC. On i686, x86\_64, and aarch64, the Terraform provider uses QEMU's firmware configuration (fw\_cfg) device to pass the Ignition config through to the Ignition instance running in the virtual machine. In order for this to work, Ignition needs to be run with `--provider=qemu`. Unfortunately, QEMU doesn't support the firmware configuration device for s390x and PowerPC guests, so alternatively, a virtio-blk device is created with a serial of `ignition` which ignition detects and reads.
 
 
 ### Using the QEMU Guest Agent

libvirt/coreos_ignition_def.go

@@ -8,8 +8,6 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
-	"os/exec"
-	"path/filepath"
 	"strings"
 
 	libvirt "github.com/libvirt/libvirt-go"
@@ -52,55 +50,17 @@ func (ign *defIgnition) CreateAndUpload(client *Client) (string, error) {
 	volumeDef := newDefVolume()
 	volumeDef.Name = ign.Name
 
-	tmpDir, err := ioutil.TempDir("", "ignition")
+	ignFile, err := ign.createFile()
 	if err != nil {
-		return "", fmt.Errorf("Failed to create Ignition directory: %v", err)
+		return "", err
 	}
 	defer func() {
-		if err = os.RemoveAll(tmpDir); err != nil {
-			log.Printf("Error while removing Ignition directory: %v", err)
+		if err = os.Remove(ignFile); err != nil {
+			log.Printf("Error while removing tmp Ignition file: %v", err)
 		}
 	}()
 
-	ignPath, err := ign.createFile(tmpDir)
-	if err != nil {
-		return "", err
-	}
-
-	arch, err := getHostArchitecture(client.libvirt)
-	if err != nil {
-		return "", fmt.Errorf("Error retrieving host architecture: %s", err)
-	}
-
-	var userdataPath string
-	switch arch {
-	case "i686", "x86_64", "aarch64":
-		userdataPath = ignPath
-	case "s390", "s390x", "ppc64", "ppc64le":
-		configDrivePath := filepath.Join(tmpDir, "config.iso")
-		cmd := exec.Command(
-			"mkisofs",
-			"-output",
-			configDrivePath,
-			"-volid",
-			"config-2",
-			"-root",
-			"openstack/latest",
-			"-joliet",
-			"-rock",
-			ignPath)
-
-		log.Printf("Executing command: %+v", cmd)
-		if err = cmd.Run(); err != nil {
-			return "", fmt.Errorf("Failed to create Config Drive ISO image: %v", err)
-		}
-
-		userdataPath = configDrivePath
-	default:
-		return "", fmt.Errorf("Ignition not supported on %q", arch)
-	}
-
-	img, err := newImage(userdataPath)
+	img, err := newImage(ignFile)
 	if err != nil {
 		return "", err
 	}
@@ -156,12 +116,12 @@ func getIgnitionVolumeKeyFromTerraformID(id string) (string, error) {
 }
 
 // Dumps the Ignition object - either generated by Terraform or supplied as a file -
-// to a userdata Ignition file in the provided directory
-func (ign *defIgnition) createFile(dir string) (string, error) {
+// to a temporary ignition file
+func (ign *defIgnition) createFile() (string, error) {
 	log.Print("Creating Ignition temporary file")
-	tempFile, err := os.Create(filepath.Join(dir, "user_data"))
+	tempFile, err := ioutil.TempFile("", ign.Name)
 	if err != nil {
-		return "", fmt.Errorf("Error creating userdata file: %v", err)
+		return "", fmt.Errorf("Error creating tmp file: %v", err)
 	}
 	defer tempFile.Close()
 

libvirt/domain.go

@@ -198,26 +198,14 @@ func domainGetIfacesInfo(domain libvirt.Domain, rd *schema.ResourceData) ([]libv
 	return interfaces, nil
 }
 
-func newDiskForCloudInit(virConn *libvirt.Connect, volumeKey string, arch string) (libvirtxml.DomainDisk, error) {
-	var target *libvirtxml.DomainDiskTarget
-	switch arch {
-	case "s390", "s390x", "ppc64", "ppc64le":
-		target = &libvirtxml.DomainDiskTarget{
-			// s390 and ppc64 platforms don't support IDE controllers
-			Dev: "vdb",
-			Bus: "scsi",
-		}
-	default:
-		target = &libvirtxml.DomainDiskTarget{
+func newDiskForCloudInit(virConn *libvirt.Connect, volumeKey string) (libvirtxml.DomainDisk, error) {
+	disk := libvirtxml.DomainDisk{
+		Device: "cdrom",
+		Target: &libvirtxml.DomainDiskTarget{
 			// Last device letter possible with a single IDE controller on i440FX
 			Dev: "hdd",
 			Bus: "ide",
-		}
-	}
-
-	disk := libvirtxml.DomainDisk{
-		Device: "cdrom",
-		Target: target,
+		},
 		Driver: &libvirtxml.DomainDiskDriver{
 			Name: "qemu",
 			Type: "raw",
@@ -270,17 +258,31 @@ func setCoreOSIgnition(d *schema.ResourceData, domainDef *libvirtxml.Domain, vir
 				}
 			}
 		case "s390", "s390x", "ppc64", "ppc64le":
-			// System Z and PowerPC do not support any of the same pass-through
-			// mechanisms as Ignition. As a temporary workaround, the OpenStack
-			// Config Drive can be used instead. The Ignition volume already
-			// contains a Config Drive at this point.
-
-			disk, err := newDiskForCloudInit(virConn, ignitionKey, arch)
-			if err != nil {
-				return err
+			// System Z and PowerPC do not support the Firmware Configuration
+			// device. After a discussion about the best way to support a similar
+			// method for qemu in https://github.com/coreos/ignition/issues/928,
+			// decided on creating a virtio-blk device with a serial of ignition
+			// which contains the ignition config and have ignition support for
+			// reading from the device which landed in https://github.com/coreos/ignition/pull/936
+			igndisk := libvirtxml.DomainDisk{
+				Device: "disk",
+				Source: &libvirtxml.DomainDiskSource{
+					File: &libvirtxml.DomainDiskSourceFile{
+						File: ignitionKey,
+					},
+				},
+				Target: &libvirtxml.DomainDiskTarget{
+					Dev: "vdb",
+					Bus: "virtio",
+				},
+				Driver: &libvirtxml.DomainDiskDriver{
+					Name: "qemu",
+					Type: "raw",
+				},
+				ReadOnly: &libvirtxml.DomainDiskReadOnly{},
+				Serial:   "ignition",
 			}
-
-			domainDef.Devices.Disks = append(domainDef.Devices.Disks, disk)
+			domainDef.Devices.Disks = append(domainDef.Devices.Disks, igndisk)
 		default:
 			return fmt.Errorf("Ignition not supported on %q", arch)
 		}
@@ -655,13 +657,13 @@ func setFilesystems(d *schema.ResourceData, domainDef *libvirtxml.Domain) error
 	return nil
 }
 
-func setCloudinit(d *schema.ResourceData, domainDef *libvirtxml.Domain, virConn *libvirt.Connect, arch string) error {
+func setCloudinit(d *schema.ResourceData, domainDef *libvirtxml.Domain, virConn *libvirt.Connect) error {
 	if cloudinit, ok := d.GetOk("cloudinit"); ok {
 		cloudinitID, err := getCloudInitVolumeKeyFromTerraformID(cloudinit.(string))
 		if err != nil {
 			return err
 		}
-		disk, err := newDiskForCloudInit(virConn, cloudinitID, arch)
+		disk, err := newDiskForCloudInit(virConn, cloudinitID)
 		if err != nil {
 			return err
 		}

libvirt/resource_libvirt_domain.go

@@ -497,7 +497,7 @@ func resourceLibvirtDomainCreate(d *schema.ResourceData, meta interface{}) error
 		return err
 	}
 
-	if err := setCloudinit(d, &domainDef, virConn, arch); err != nil {
+	if err := setCloudinit(d, &domainDef, virConn); err != nil {
 		return err
 	}
 
@@ -652,12 +652,7 @@ func resourceLibvirtDomainUpdate(d *schema.ResourceData, meta interface{}) error
 			return err
 		}
 
-		arch, err := getHostArchitecture(virConn)
-		if err != nil {
-			return fmt.Errorf("Error retrieving host architecture: %s", err)
-		}
-
-		disk, err := newDiskForCloudInit(virConn, cloudinitID, arch)
+		disk, err := newDiskForCloudInit(virConn, cloudinitID)
 		if err != nil {
 			return err
 		}

website/docs/r/coreos_ignition.html.markdown

@@ -16,10 +16,9 @@ a CoreOS Domain during first boot.
 
 ~> **Note:** On the i686 (x86), x86\_64 (AMD64), and aarch64 (ARM64) platforms,
 the QEMU firmware config device (`-fw_cfg`) is used to pass Ignition configs
-into the guests. On the s390x (IBM Z) platform however, the QEMU firmware
-config device is not supported. As alternative, the OpenStack config-drive
-mechanism is instead used. The `mkisofs` utility must be installed into the
-path and Ignition must be run with the `--provider=openstack` flag.
+into the guests. On the s390x (IBM Z) and PowerPC platforms however, the QEMU firmware
+config device is not supported. As an alternative, a virtio-blk device is created with a serial
+of `ignition` which ignition recognizes and reads the config from the device
 
 ## Example Usage