Merge pull request #1521 from thebsdbox/qemu

CLI: Added qemu backend

src/cmd/moby/run.go

@@ -16,6 +16,7 @@ func runUsage() {
 	fmt.Printf("Supported backends are (default platform in brackets):\n")
 	fmt.Printf("  gcp\n")
 	fmt.Printf("  hyperkit [macOS]\n")
+	fmt.Printf("  qemu [linux]\n")
 	fmt.Printf("  vmware\n")
 	fmt.Printf("\n")
 	fmt.Printf("'options' are the backend specific options.\n")
@@ -40,10 +41,14 @@ func run(args []string) {
 		runVMware(args[1:])
 	case "gcp":
 		runGcp(args[1:])
+	case "qemu":
+		runQemu(args[1:])
 	default:
 		switch runtime.GOOS {
 		case "darwin":
 			runHyperKit(args)
+		case "linux":
+			runQemu(args)
 		default:
 			log.Errorf("There currently is no default 'run' backend for your platform.")
 		}

src/cmd/moby/run_qemu.go

@@ -0,0 +1,161 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"os"
+	"os/exec"
+
+	log "github.com/Sirupsen/logrus"
+)
+
+func runQemu(args []string) {
+	qemuFlags := flag.NewFlagSet("qemu", flag.ExitOnError)
+	qemuFlags.Usage = func() {
+		fmt.Printf("USAGE: %s run qemu [options] prefix\n\n", os.Args[0])
+		fmt.Printf("'prefix' specifies the path to the VM image.\n")
+		fmt.Printf("\n")
+		fmt.Printf("Options:\n")
+		qemuFlags.PrintDefaults()
+	}
+
+	// Determine Flags
+	qemuGUI := qemuFlags.Bool("gui", false, "Set qemu to use video output instead of stdio")
+	qemuUEFI := qemuFlags.Bool("uefi", false, "Set UEFI boot from 'prefix'-efi.iso")
+	qemuIso := qemuFlags.Bool("iso", false, "Set Legacy BIOS boot from 'prefix'.iso")
+	qemuKernel := qemuFlags.Bool("kernel", true, "Set boot using 'prefix'-bzImage/-initrd/-cmdline")
+
+	// Paths and settings for Disks and UEFI firware
+	qemuDiskPath := qemuFlags.String("diskpath", "", "Path to disk image to use")
+	qemuDiskSize := qemuFlags.String("disksize", "", "Size of disk to create, only created if it doesn't exist")
+	qemuFWPath := qemuFlags.String("fwpath", "/usr/share/ovmf/bios.bin", "Path to OVMF firmware for UEFI boot")
+
+	// VM configuration
+	qemuArch := qemuFlags.String("arch", "x86_64", "Type of architecture to use, e.g. x86_64, aarch64")
+	qemuCPUs := qemuFlags.String("cpus", "1", "Number of CPUs")
+	qemuMem := qemuFlags.String("mem", "1024", "Amount of memory in MB")
+
+	qemuFlags.Parse(args)
+	remArgs := qemuFlags.Args()
+
+	if len(remArgs) == 0 {
+		fmt.Println("Please specify the prefix to the image to boot")
+		qemuFlags.Usage()
+		os.Exit(1)
+	}
+	prefix := remArgs[0]
+
+	// Print warning if conflicting UEFI and ISO flags are set
+	if *qemuUEFI && *qemuIso {
+		log.Warnf("Both -iso and -uefi have been used")
+	}
+
+	// Before building qemu arguments, check qemu is in the $PATH
+	qemuBinPath := "qemu-system-" + *qemuArch
+	qemuImgPath := "qemu-img"
+	fullQemuPath, err := exec.LookPath(qemuBinPath)
+	if err != nil {
+		log.Fatalf("Unable to find %s within the $PATH", qemuBinPath)
+	}
+
+	// Iterate through the flags and build arguments
+	var qemuArgs []string
+	qemuArgs = append(qemuArgs, "-device", "virtio-rng-pci")
+	qemuArgs = append(qemuArgs, "-smp", *qemuCPUs)
+	qemuArgs = append(qemuArgs, "-m", *qemuMem)
+
+	// Look for kvm device and enable for qemu if it exists
+	if _, err = os.Stat("/dev/kvm"); os.IsNotExist(err) {
+		qemuArgs = append(qemuArgs, "-machine", "q35")
+	} else {
+		qemuArgs = append(qemuArgs, "-enable-kvm")
+		qemuArgs = append(qemuArgs, "-machine", "q35,accel=kvm:tcg")
+	}
+
+	if *qemuDiskPath != "" {
+		// If disk doesn't exist then create one
+		if _, err = os.Stat(*qemuDiskPath); os.IsNotExist(err) {
+			log.Infof("Creating new qemu disk [%s]", *qemuDiskPath)
+			fullQemuImgPath, err := exec.LookPath(qemuImgPath)
+			if err != nil {
+				log.Fatalf("Unable to find %s within the $PATH", qemuImgPath)
+			}
+			cmd := exec.Command(fullQemuImgPath, "create", "-f", "qcow2", *qemuDiskPath, *qemuDiskSize)
+			cmd.Run()
+		} else {
+			log.Infof("Using existing disk [%s]", *qemuDiskPath)
+		}
+		qemuArgs = append(qemuArgs, "-disk", "file="+*qemuDiskPath+",format=raw")
+	}
+
+	// Check flags for iso/uefi boot and if so disable kernel boot
+	if *qemuIso {
+		*qemuKernel = false
+		qemuIsoPath := buildPath(prefix, ".iso")
+		qemuArgs = append(qemuArgs, "-cdrom", qemuIsoPath)
+	}
+
+	if *qemuUEFI {
+		// Check for OVMF firmware before building paths
+		_, err = os.Stat(*qemuFWPath)
+		if err != nil {
+			if os.IsNotExist(err) {
+				log.Fatalf("File [%s] does not exist, please ensure OVMF is installed", *qemuFWPath)
+			} else {
+				log.Fatalf("%s", err.Error())
+			}
+		}
+
+		*qemuKernel = false
+		qemuIsoPath := buildPath(prefix, "-efi.iso")
+		qemuArgs = append(qemuArgs, "-pflash", *qemuFWPath)
+		qemuArgs = append(qemuArgs, "-cdrom", qemuIsoPath)
+		qemuArgs = append(qemuArgs, "-boot", "d")
+	}
+
+	// build kernel boot config from bzImage/initrd/cmdline
+	if *qemuKernel {
+		qemuKernelPath := buildPath(prefix, "-bzImage")
+		qemuInitrdPath := buildPath(prefix, "-initrd.img")
+		qemuArgs = append(qemuArgs, "-kernel", qemuKernelPath)
+		qemuArgs = append(qemuArgs, "-initrd", qemuInitrdPath)
+		consoleString, err := ioutil.ReadFile(prefix + "-cmdline")
+		if err != nil {
+			log.Infof(" %s\n defaulting to console output", err.Error())
+			qemuArgs = append(qemuArgs, "-append", "console=ttyS0 console=tty0 page_poison=1")
+		} else {
+			qemuArgs = append(qemuArgs, "-append", string(consoleString))
+		}
+	}
+
+	if *qemuGUI != true {
+		qemuArgs = append(qemuArgs, "-nographic")
+	}
+
+	// If verbosity is enabled print out the full path/arguments
+	log.Debugf("%s %v\n", fullQemuPath, qemuArgs)
+
+	cmd := exec.Command(fullQemuPath, qemuArgs...)
+
+	// If we're not using a seperate window then link the execution to stdin/out
+	if *qemuGUI != true {
+		cmd.Stdin = os.Stdin
+		cmd.Stdout = os.Stdout
+		cmd.Stderr = os.Stderr
+	}
+
+	err = cmd.Run()
+
+	if err != nil {
+		log.Fatalf("Error starting %s\nError: %s", fullQemuPath, err.Error())
+	}
+}
+
+func buildPath(prefix string, postfix string) string {
+	path := prefix + postfix
+	if _, err := os.Stat(path); os.IsNotExist(err) {
+		log.Fatalf("File [%s] does not exist in current directory", path)
+	}
+	return path
+}