Podman machine enhancements

Podman machine remove is now called `rm`.

Podman machine create now supports resizing the image to the value of
--disk-size as provided.  The default is to 10G.

Added systemd unit file on guest via ignition that sends a Ready message
to the host over a virtio-socket so that we know when the VM is booted
and ready for use.

Podman machine commands no longer require a VM name as an argument.  A
default VM name is defined and if no VM name is provided as a arg, the
default will be used.

[NO TESTS NEEDED]

Signed-off-by: baude <bbaude@redhat.com>

3 files changed, 103 insertions, 23 deletions

diff --git a/pkg/machine/config.go b/pkg/machine/config.go
index 4933deee8..273deca00 100644
--- a/pkg/machine/config.go
+++ b/pkg/machine/config.go
@@ -7,19 +7,19 @@ import (
 	"path/filepath"
 
 	"github.com/containers/storage/pkg/homedir"
+	"github.com/pkg/errors"
 )
 
 type InitOptions struct {
-	Name         string
 	CPUS         uint64
-	Memory       uint64
+	DiskSize     uint64
 	IgnitionPath string
 	ImagePath    string
-	Username     string
-	URI          url.URL
 	IsDefault    bool
-	//KernelPath string
-	//Devices    []VMDevices
+	Memory       uint64
+	Name         string
+	URI          url.URL
+	Username     string
 }
 
 type RemoteConnectionType string
@@ -27,6 +27,8 @@ type RemoteConnectionType string
 var (
 	SSHRemoteConnection     RemoteConnectionType = "ssh"
 	DefaultIgnitionUserName                      = "core"
+	ErrNoSuchVM                                  = errors.New("VM does not exist")
+	ErrVMAlreadyExists                           = errors.New("VM already exists")
 )
 
 type Download struct {
diff --git a/pkg/machine/ignition.go b/pkg/machine/ignition.go
index ff79d5afb..a68d68ac3 100644
--- a/pkg/machine/ignition.go
+++ b/pkg/machine/ignition.go
@@ -2,6 +2,7 @@ package machine
 
 import (
 	"encoding/json"
+	"fmt"
 	"io/ioutil"
 )
 
@@ -37,10 +38,17 @@ func getNodeGrp(grpName string) NodeGroup {
 	return NodeGroup{Name: &grpName}
 }
 
+type DynamicIgnition struct {
+	Name      string
+	Key       string
+	VMName    string
+	WritePath string
+}
+
 // NewIgnitionFile
-func NewIgnitionFile(name, key, writePath string) error {
-	if len(name) < 1 {
-		name = DefaultIgnitionUserName
+func NewIgnitionFile(ign DynamicIgnition) error {
+	if len(ign.Name) < 1 {
+		ign.Name = DefaultIgnitionUserName
 	}
 	ignVersion := Ignition{
 		Version: "3.2.0",
@@ -48,23 +56,44 @@ func NewIgnitionFile(name, key, writePath string) error {
 
 	ignPassword := Passwd{
 		Users: []PasswdUser{{
-			Name:              name,
-			SSHAuthorizedKeys: []SSHAuthorizedKey{SSHAuthorizedKey(key)},
+			Name:              ign.Name,
+			SSHAuthorizedKeys: []SSHAuthorizedKey{SSHAuthorizedKey(ign.Key)},
 		}},
 	}
 
 	ignStorage := Storage{
-		Directories: getDirs(name),
-		Files:       getFiles(name),
-		Links:       getLinks(name),
+		Directories: getDirs(ign.Name),
+		Files:       getFiles(ign.Name),
+		Links:       getLinks(ign.Name),
 	}
+
+	// ready is a unit file that sets up the virtual serial device
+	// where when the VM is done configuring, it will send an ack
+	// so a listening host knows it can being interacting with it
+	ready := `[Unit]
+Requires=dev-virtio\\x2dports-%s.device
+OnFailure=emergency.target
+OnFailureJobMode=isolate
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+ExecStart=/bin/sh -c '/usr/bin/echo Ready >/dev/%s'
+[Install]
+RequiredBy=multi-user.target
+`
+	_ = ready
 	ignSystemd := Systemd{
 		Units: []Unit{
 			{
 				Enabled: boolToPtr(true),
 				Name:    "podman.socket",
-			}}}
-
+			},
+			{
+				Enabled:  boolToPtr(true),
+				Name:     "ready.service",
+				Contents: strToPtr(fmt.Sprintf(ready, "vport1p1", "vport1p1")),
+			},
+		}}
 	ignConfig := Config{
 		Ignition: ignVersion,
 		Passwd:   ignPassword,
@@ -75,7 +104,7 @@ func NewIgnitionFile(name, key, writePath string) error {
 	if err != nil {
 		return err
 	}
-	return ioutil.WriteFile(writePath, b, 0644)
+	return ioutil.WriteFile(ign.WritePath, b, 0644)
 }
 
 func getDirs(usrName string) []Directory {
diff --git a/pkg/machine/qemu/machine.go b/pkg/machine/qemu/machine.go
index b97eb991a..fe155750f 100644
--- a/pkg/machine/qemu/machine.go
+++ b/pkg/machine/qemu/machine.go
@@ -1,9 +1,11 @@
 package qemu
 
 import (
+	"bufio"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
+	"net"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -22,9 +24,6 @@ import (
 var (
 	// vmtype refers to qemu (vs libvirt, krun, etc)
 	vmtype = "qemu"
-	// qemuCommon are the common command line arguments between the arches
-	//qemuCommon = []string{"-cpu", "host", "-qmp", "unix://tmp/qmp.sock,server,nowait"}
-	//qemuCommon  = []string{"-cpu", "host", "-qmp", "tcp:localhost:4444,server,nowait"}
 )
 
 // NewMachine initializes an instance of a virtual machine based on the qemu
@@ -89,6 +88,16 @@ func NewMachine(opts machine.InitOptions) (machine.VM, error) {
 	// Add network
 	cmd = append(cmd, "-nic", "user,model=virtio,hostfwd=tcp::"+strconv.Itoa(vm.Port)+"-:22")
 
+	socketPath, err := getSocketDir()
+	if err != nil {
+		return nil, err
+	}
+	virtualSocketPath := filepath.Join(socketPath, "podman", vm.Name+"_ready.sock")
+	// Add serial port for readiness
+	cmd = append(cmd, []string{
+		"-device", "virtio-serial",
+		"-chardev", "socket,path=" + virtualSocketPath + ",server,nowait,id=" + vm.Name + "_ready",
+		"-device", "virtserialport,chardev=" + vm.Name + "_ready" + ",name=org.fedoraproject.port.0"}...)
 	vm.CmdLine = cmd
 	return vm, nil
 }
@@ -96,13 +105,15 @@ func NewMachine(opts machine.InitOptions) (machine.VM, error) {
 // LoadByName reads a json file that describes a known qemu vm
 // and returns a vm instance
 func LoadVMByName(name string) (machine.VM, error) {
-	// TODO need to define an error relating to ErrMachineNotFound
 	vm := new(MachineVM)
 	vmConfigDir, err := machine.GetConfDir(vmtype)
 	if err != nil {
 		return nil, err
 	}
 	b, err := ioutil.ReadFile(filepath.Join(vmConfigDir, name+".json"))
+	if os.IsNotExist(err) {
+		return nil, errors.Wrap(machine.ErrNoSuchVM, name)
+	}
 	if err != nil {
 		return nil, err
 	}
@@ -159,14 +170,28 @@ func (v *MachineVM) Init(opts machine.InitOptions) error {
 	if err := v.prepare(); err != nil {
 		return err
 	}
+
+	// Resize the disk image to input disk size
+	resize := exec.Command("qemu-img", []string{"resize", v.ImagePath, strconv.Itoa(int(opts.DiskSize)) + "G"}...)
+	if err := resize.Run(); err != nil {
+		return errors.Errorf("error resizing image: %q", err)
+	}
 	// Write the ignition file
-	return machine.NewIgnitionFile(opts.Username, key, v.IgnitionFilePath)
+	ign := machine.DynamicIgnition{
+		Name:      opts.Username,
+		Key:       key,
+		VMName:    v.Name,
+		WritePath: v.IgnitionFilePath,
+	}
+	return machine.NewIgnitionFile(ign)
 }
 
 // Start executes the qemu command line and forks it
 func (v *MachineVM) Start(name string, _ machine.StartOptions) error {
 	var (
-		err error
+		conn net.Conn
+		err  error
+		wait time.Duration = time.Millisecond * 500
 	)
 	attr := new(os.ProcAttr)
 	files := []*os.File{os.Stdin, os.Stdout, os.Stderr}
@@ -181,6 +206,30 @@ func (v *MachineVM) Start(name string, _ machine.StartOptions) error {
 	}
 
 	_, err = os.StartProcess(v.CmdLine[0], cmd, attr)
+	if err != nil {
+		return err
+	}
+	fmt.Println("Waiting for VM ...")
+	socketPath, err := getSocketDir()
+	if err != nil {
+		return err
+	}
+
+	// The socket is not made until the qemu process is running so here
+	// we do a backoff waiting for it.  Once we have a conn, we break and
+	// then wait to read it.
+	for i := 0; i < 6; i++ {
+		conn, err = net.Dial("unix", filepath.Join(socketPath, "podman", v.Name+"_ready.sock"))
+		if err == nil {
+			break
+		}
+		time.Sleep(wait)
+		wait++
+	}
+	if err != nil {
+		return err
+	}
+	_, err = bufio.NewReader(conn).ReadString('\n')
 	return err
 }