Merge pull request #629 from jichenjc/add_guestfish_support

Add coreos ignition through guestfs on s390 platform

Author: MalloZup

libvirt/domain.go

@@ -1,11 +1,16 @@
 package libvirt
 
 import (
+	"bytes"
 	"errors"
 	"fmt"
+	"io"
 	"log"
 	"net"
 	"net/url"
+	"os"
+	"os/exec"
+	"runtime"
 	"sort"
 	"strconv"
 	"strings"
@@ -230,7 +235,143 @@ func newDiskForCloudInit(virConn *libvirt.Connect, volumeKey string) (libvirtxml
 	return disk, nil
 }
 
-func setCoreOSIgnition(d *schema.ResourceData, domainDef *libvirtxml.Domain) error {
+func getFirstDiskPath(d *schema.ResourceData, domainDef *libvirtxml.Domain, virConn *libvirt.Connect) (string, error) {
+	prefix := fmt.Sprintf("disk.%d", 0)
+
+	if volumeKey, ok := d.GetOk(prefix + ".volume_id"); ok {
+		diskVolume, err := virConn.LookupStorageVolByKey(volumeKey.(string))
+		if err != nil {
+			return "", fmt.Errorf("Error lookup storage disk volume: %s", err)
+		}
+		diskVolumeFile, err := diskVolume.GetPath()
+		if err != nil {
+			return "", fmt.Errorf("Error get path of disk volume: %s", err)
+		}
+		return diskVolumeFile, nil
+	}
+	return "", fmt.Errorf("failed to find disk 0")
+}
+
+func getStderr(stderr io.ReadCloser) string {
+	buf := new(bytes.Buffer)
+	buf.ReadFrom(stderr)
+	return buf.String()
+}
+
+func inlineUpdateCoreOsIgnition(d *schema.ResourceData, domainDef *libvirtxml.Domain, virConn *libvirt.Connect) error {
+	if ignition, ok := d.GetOk("coreos_ignition"); ok {
+
+		// Get the root disk (first disk) volume location
+		rootPath, err := getFirstDiskPath(d, domainDef, virConn)
+		if err != nil {
+			return err
+		}
+
+		// Get the ingition file to be uploaded
+		ignitionKey, err := getIgnitionVolumeKeyFromTerraformID(ignition.(string))
+		if err != nil {
+			return err
+		}
+		diskVolume, err := virConn.LookupStorageVolByKey(ignitionKey)
+		if err != nil {
+			return err
+		}
+		fileToUpload, err := diskVolume.GetPath()
+		if err != nil {
+			return err
+		}
+		err = guestfishExecution(rootPath, fileToUpload)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+var execCommand = exec.Command
+
+func guestfishExecution(rootPath string, fileToUpload string) error {
+	// This is the file in coreos image going to be copied from local
+	fileRemoteLocation := "/ignition/config.ign"
+
+	// eval  $(guestfish --listen -a $1)
+	cmd := execCommand("guestfish", "--listen", "-a", rootPath)
+	stdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return fmt.Errorf("Get stdout failed: %v", err)
+	}
+	stderr, err := cmd.StderrPipe()
+	if err != nil {
+		return fmt.Errorf("Get stderr failed: %v", err)
+	}
+
+	err = cmd.Start()
+	if err != nil {
+		return fmt.Errorf("Start command failed: %v", err)
+	}
+
+	// if the command start successfully, the output will be following format
+	// GUESTFISH_PID=xxxx; export GUESTFISH_PID, so we need get the PID and set by using os.Setenv
+	buf := new(bytes.Buffer)
+	buf.ReadFrom(stdout)
+	guestfishPidLabel := strings.Split(buf.String(), ";")
+	guestfishPidValue := strings.Split(guestfishPidLabel[0], "=")
+	os.Setenv(guestfishPidValue[0], guestfishPidValue[1])
+
+	// guestfish --remote -- run
+	cmd = execCommand("guestfish", "--remote", "--", "run")
+	err = cmd.Run()
+	if err != nil {
+		return fmt.Errorf("Launch failed: %v, %s", err, getStderr(stderr))
+	}
+
+	// guestfish --remote -- exit
+	defer func() {
+		cmd := execCommand("guestfish", "--remote", "--", "exit")
+		cmd.Run()
+	}()
+
+	// guestfish --remote -- findfs-label
+	cmd = execCommand("guestfish", "--remote", "--", "findfs-label", "boot")
+	output, err := cmd.Output()
+
+	if err != nil {
+		return fmt.Errorf("Failed to find fs label: %v", err)
+	}
+
+	bootDisk := strings.TrimSpace(string(output))
+	if len(bootDisk) == 0 {
+		return fmt.Errorf("failed to get the boot filesystem")
+	}
+
+	// guestfish --remote -- mount $2 /
+	cmd = execCommand("guestfish", "--remote", "--", "mount", bootDisk, "/")
+	err = cmd.Run()
+	if err != nil {
+		return fmt.Errorf("Mount failed: %v, %s", err, getStderr(stderr))
+	}
+
+	// This is the real command that upload the file from current location (the local file system)
+	// to remote file location (the coreos file system)
+	// guestfish --remote -- upload $4 $3/$4
+	cmd = execCommand("guestfish", "--remote", "--", "upload", fileToUpload, fileRemoteLocation)
+	err = cmd.Run()
+	if err != nil {
+		return fmt.Errorf("Upload failed: %v, %s", err, getStderr(stderr))
+	}
+
+	// guestfish --remote -- umount-all
+	cmd = execCommand("guestfish", "--remote", "--", "umount-all")
+	err = cmd.Run()
+	if err != nil {
+		return fmt.Errorf("Unmount failed: %v, %s", err, getStderr(stderr))
+	}
+
+	return nil
+}
+
+// Use fw_cfg device to update coresos
+func fwcfgUpdateCoreOSIgnition(d *schema.ResourceData, domainDef *libvirtxml.Domain) error {
 	if ignition, ok := d.GetOk("coreos_ignition"); ok {
 		ignitionKey, err := getIgnitionVolumeKeyFromTerraformID(ignition.(string))
 		if err != nil {
@@ -256,6 +397,15 @@ func setCoreOSIgnition(d *schema.ResourceData, domainDef *libvirtxml.Domain) err
 	return nil
 }
 
+func updateCoreOSIgnition(d *schema.ResourceData, domainDef *libvirtxml.Domain, virConn *libvirt.Connect) error {
+	if runtime.GOARCH == "s390x" || runtime.GOARCH == "s390" {
+		// There is no support for fw_cfg in s390x, so instead of doing fw_cfg
+		// we have to inline update the coreos ignition file
+		return inlineUpdateCoreOsIgnition(d, domainDef, virConn)
+	}
+	return fwcfgUpdateCoreOSIgnition(d, domainDef)
+}
+
 func setVideo(d *schema.ResourceData, domainDef *libvirtxml.Domain) error {
 	prefix := "video.0"
 	if _, ok := d.GetOk(prefix); ok {