Introduce podman machine init --root=t|f and podman machine set --root=t|f

Switch default to rootless for mac and windows

Signed-off-by: Jason T. Greene <jason.greene@redhat.com>

cmd/podman/machine/init.go

@@ -26,7 +26,7 @@ var (
 
 var (
 	initOpts           = machine.InitOptions{}
-	defaultMachineName = "podman-machine-default"
+	defaultMachineName = machine.DefaultMachineName
 	now                bool
 )
 
@@ -99,6 +99,9 @@ func init() {
 	IgnitionPathFlagName := "ignition-path"
 	flags.StringVar(&initOpts.IgnitionPath, IgnitionPathFlagName, "", "Path to ignition file")
 	_ = initCmd.RegisterFlagCompletionFunc(IgnitionPathFlagName, completion.AutocompleteDefault)
+
+	rootfulFlagName := "rootful"
+	flags.BoolVar(&initOpts.Rootful, rootfulFlagName, false, "Whether this machine should prefer rootful container exectution")
 }
 
 // TODO should we allow for a users to append to the qemu cmdline?

cmd/podman/machine/set.go

@@ -0,0 +1,56 @@
+// +build amd64 arm64
+
+package machine
+
+import (
+	"github.com/containers/common/pkg/completion"
+	"github.com/containers/podman/v4/cmd/podman/registry"
+	"github.com/containers/podman/v4/pkg/machine"
+	"github.com/spf13/cobra"
+)
+
+var (
+	setCmd = &cobra.Command{
+		Use:               "set [options] [NAME]",
+		Short:             "Sets a virtual machine setting",
+		Long:              "Sets an updatable virtual machine setting",
+		RunE:              setMachine,
+		Args:              cobra.MaximumNArgs(1),
+		Example:           `podman machine set --root=false`,
+		ValidArgsFunction: completion.AutocompleteNone,
+	}
+)
+
+var (
+	setOpts = machine.SetOptions{}
+)
+
+func init() {
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Command: setCmd,
+		Parent:  machineCmd,
+	})
+	flags := setCmd.Flags()
+
+	rootfulFlagName := "rootful"
+	flags.BoolVar(&setOpts.Rootful, rootfulFlagName, false, "Whether this machine should prefer rootful container execution")
+}
+
+func setMachine(cmd *cobra.Command, args []string) error {
+	var (
+		vm  machine.VM
+		err error
+	)
+
+	vmName := defaultMachineName
+	if len(args) > 0 && len(args[0]) > 0 {
+		vmName = args[0]
+	}
+	provider := getSystemDefaultProvider()
+	vm, err = provider.LoadVMByName(vmName)
+	if err != nil {
+		return err
+	}
+
+	return vm.Set(vmName, setOpts)
+}

docs/source/markdown/podman-machine-init.1.md

@@ -55,6 +55,14 @@ Memory (in MB).
 
 Start the virtual machine immediately after it has been initialized.
 
+#### **--rootful**=*true|false*
+
+Whether this machine should prefer rootful (`true`) or rootless (`false`)
+container execution. This option will also determine the remote connection default
+if there is no existing remote connection configurations.
+
+API forwarding, if available, will follow this setting.
+
 #### **--timezone**
 
 Set the timezone for the machine and containers.  Valid values are `local` or
@@ -84,6 +92,7 @@ Print usage statement.
 ```
 $ podman machine init
 $ podman machine init myvm
+$ podman machine init --rootful
 $ podman machine init --disk-size 50
 $ podman machine init --memory=1024 myvm
 $ podman machine init -v /Users:/mnt/Users

docs/source/markdown/podman-machine-set.1.md

@@ -0,0 +1,59 @@
+% podman-machine-set(1)
+
+## NAME
+podman\-machine\-set - Sets a virtual machine setting
+
+## SYNOPSIS
+**podman machine set** [*options*] [*name*]
+
+## DESCRIPTION
+
+Sets an updatable virtual machine setting.
+
+Options mirror values passed to `podman machine init`. Only a limited
+subset can be changed after machine initialization.
+
+## OPTIONS
+
+#### **--rootful**=*true|false*
+
+Whether this machine should prefer rootful (`true`) or rootless (`false`)
+container execution. This option will also update the current podman
+remote connection default if it is currently pointing at the specified
+machine name (or `podman-machine-default` if no name is specified).
+
+API forwarding, if available, will follow this setting.
+
+#### **--help**
+
+Print usage statement.
+
+## EXAMPLES
+
+To switch the default VM `podman-machine-default` from rootless to rootful:
+
+```
+$ podman machine set --rootful
+```
+
+or more explicitly:
+
+```
+$ podman machine set --rootful=true
+```
+
+To switch the default VM `podman-machine-default` from rootful to rootless:
+```
+$ podman machine set --rootful=false
+```
+
+To switch the VM `myvm` from rootless to rootful:
+```
+$ podman machine set --rootful myvm
+```
+
+## SEE ALSO
+**[podman(1)](podman.1.md)**, **[podman-machine(1)](podman-machine.1.md)**
+
+## HISTORY
+February 2022, Originally compiled by Jason Greene <jason.greene@redhat.com>

docs/source/markdown/podman-machine.1.md

@@ -16,6 +16,7 @@ podman\-machine - Manage Podman's virtual machine
 | init    | [podman-machine-init(1)](podman-machine-init.1.md)      | Initialize a new virtual machine  |
 | list    | [podman-machine-list(1)](podman-machine-list.1.md)      | List virtual machines             |
 | rm      | [podman-machine-rm(1)](podman-machine-rm.1.md)          | Remove a virtual machine          |
+| set     | [podman-machine-set(1)](podman-machine-set.1.md)        | Sets a virtual machine setting    |
 | ssh     | [podman-machine-ssh(1)](podman-machine-ssh.1.md)        | SSH into a virtual machine        |
 | start   | [podman-machine-start(1)](podman-machine-start.1.md)    | Start a virtual machine           |
 | stop    | [podman-machine-stop(1)](podman-machine-stop.1.md)      | Stop a virtual machine            |

pkg/machine/config.go

@@ -27,6 +27,7 @@ type InitOptions struct {
 	URI          url.URL
 	Username     string
 	ReExec       bool
+	Rootful      bool
 }
 
 type QemuMachineStatus = string
@@ -35,7 +36,8 @@ const (
 	// Running indicates the qemu vm is running
 	Running QemuMachineStatus = "running"
 	//	Stopped indicates the vm has stopped
-	Stopped QemuMachineStatus = "stopped"
+	Stopped            QemuMachineStatus = "stopped"
+	DefaultMachineName string            = "podman-machine-default"
 )
 
 type Provider interface {
@@ -89,6 +91,10 @@ type ListResponse struct {
 	IdentityPath   string
 }
 
+type SetOptions struct {
+	Rootful bool
+}
+
 type SSHOptions struct {
 	Username string
 	Args     []string
@@ -107,6 +113,7 @@ type RemoveOptions struct {
 type VM interface {
 	Init(opts InitOptions) (bool, error)
 	Remove(name string, opts RemoveOptions) (string, func() error, error)
+	Set(name string, opts SetOptions) error
 	SSH(name string, opts SSHOptions) error
 	Start(name string, opts StartOptions) error
 	Stop(name string, opts StopOptions) error

pkg/machine/connection.go

@@ -39,6 +39,31 @@ func AddConnection(uri fmt.Stringer, name, identity string, isDefault bool) erro
 	return cfg.Write()
 }
 
+func AnyConnectionDefault(name ...string) (bool, error) {
+	cfg, err := config.ReadCustomConfig()
+	if err != nil {
+		return false, err
+	}
+	for _, n := range name {
+		if n == cfg.Engine.ActiveService {
+			return true, nil
+		}
+	}
+
+	return false, nil
+}
+
+func ChangeDefault(name string) error {
+	cfg, err := config.ReadCustomConfig()
+	if err != nil {
+		return err
+	}
+
+	cfg.Engine.ActiveService = name
+
+	return cfg.Write()
+}
+
 func RemoveConnection(name string) error {
 	cfg, err := config.ReadCustomConfig()
 	if err != nil {

pkg/machine/qemu/config.go

@@ -33,6 +33,8 @@ type MachineVM struct {
 	QMPMonitor Monitor
 	// RemoteUsername of the vm user
 	RemoteUsername string
+	// Whether this machine should run in a rootful or rootless manner
+	Rootful bool
 }
 
 type Mount struct {

pkg/machine/qemu/machine.go

@@ -5,14 +5,15 @@ package qemu
 
 import (
 	"bufio"
-	"encoding/base64"
 	"context"
+	"encoding/base64"
 	"encoding/json"
 	"fmt"
 	"io/fs"
 	"io/ioutil"
 	"net"
 	"net/http"
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -166,14 +167,8 @@ func (v *MachineVM) Init(opts machine.InitOptions) (bool, error) {
 		key string
 	)
 	sshDir := filepath.Join(homedir.Get(), ".ssh")
-	// GetConfDir creates the directory so no need to check for
-	// its existence
-	vmConfigDir, err := machine.GetConfDir(vmtype)
-	if err != nil {
-		return false, err
-	}
-	jsonFile := filepath.Join(vmConfigDir, v.Name) + ".json"
 	v.IdentityPath = filepath.Join(sshDir, v.Name)
+	v.Rootful = opts.Rootful
 
 	switch opts.ImagePath {
 	case "testing", "next", "stable", "":
@@ -256,29 +251,33 @@ func (v *MachineVM) Init(opts machine.InitOptions) (bool, error) {
 	// This kind of stinks but no other way around this r/n
 	if len(opts.IgnitionPath) < 1 {
 		uri := machine.SSHRemoteConnection.MakeSSHURL("localhost", "/run/user/1000/podman/podman.sock", strconv.Itoa(v.Port), v.RemoteUsername)
-		if err := machine.AddConnection(&uri, v.Name, filepath.Join(sshDir, v.Name), opts.IsDefault); err != nil {
+		uriRoot := machine.SSHRemoteConnection.MakeSSHURL("localhost", "/run/podman/podman.sock", strconv.Itoa(v.Port), "root")
-			return false, err
+		identity := filepath.Join(sshDir, v.Name)
+
+		uris := []url.URL{uri, uriRoot}
+		names := []string{v.Name, v.Name + "-root"}
+
+		// The first connection defined when connections is empty will become the default
+		// regardless of IsDefault, so order according to rootful
+		if opts.Rootful {
+			uris[0], names[0], uris[1], names[1] = uris[1], names[1], uris[0], names[0]
 		}
 
-		uriRoot := machine.SSHRemoteConnection.MakeSSHURL("localhost", "/run/podman/podman.sock", strconv.Itoa(v.Port), "root")
+		for i := 0; i < 2; i++ {
-		if err := machine.AddConnection(&uriRoot, v.Name+"-root", filepath.Join(sshDir, v.Name), opts.IsDefault); err != nil {
+			if err := machine.AddConnection(&uris[i], names[i], identity, opts.IsDefault && i == 0); err != nil {
-			return false, err
+				return false, err
+			}
 		}
 	} else {
 		fmt.Println("An ignition path was provided.  No SSH connection was added to Podman")
 	}
 	// Write the JSON file
-	b, err := json.MarshalIndent(v, "", " ")
+	v.writeConfig()
-	if err != nil {
-		return false, err
-	}
-	if err := ioutil.WriteFile(jsonFile, b, 0644); err != nil {
-		return false, err
-	}
 
 	// User has provided ignition file so keygen
 	// will be skipped.
 	if len(opts.IgnitionPath) < 1 {
+		var err error
 		key, err = machine.CreateSSHKeys(v.IdentityPath)
 		if err != nil {
 			return false, err
@@ -325,6 +324,30 @@ func (v *MachineVM) Init(opts machine.InitOptions) (bool, error) {
 	return err == nil, err
 }
 
+func (v *MachineVM) Set(name string, opts machine.SetOptions) error {
+	if v.Rootful == opts.Rootful {
+		return nil
+	}
+
+	changeCon, err := machine.AnyConnectionDefault(v.Name, v.Name+"-root")
+	if err != nil {
+		return err
+	}
+
+	if changeCon {
+		newDefault := v.Name
+		if opts.Rootful {
+			newDefault += "-root"
+		}
+		if err := machine.ChangeDefault(newDefault); err != nil {
+			return err
+		}
+	}
+
+	v.Rootful = opts.Rootful
+	return v.writeConfig()
+}
+
 // Start executes the qemu command line and forks it
 func (v *MachineVM) Start(name string, _ machine.StartOptions) error {
 	var (
@@ -457,7 +480,7 @@ func (v *MachineVM) Start(name string, _ machine.StartOptions) error {
 		}
 	}
 
-	printAPIForwardInstructions(forwardState, forwardSock)
+	waitAPIAndPrintInfo(forwardState, forwardSock, v.Rootful, v.Name)
 
 	return nil
 }
@@ -929,9 +952,17 @@ func (v *MachineVM) setupAPIForwarding(cmd []string) ([]string, string, apiForwa
 		return cmd, "", noForwarding
 	}
 
+	destSock := "/run/user/1000/podman/podman.sock"
+	forwardUser := "core"
+
+	if v.Rootful {
+		destSock = "/run/podman/podman.sock"
+		forwardUser = "root"
+	}
+
 	cmd = append(cmd, []string{"-forward-sock", socket}...)
-	cmd = append(cmd, []string{"-forward-dest", "/run/podman/podman.sock"}...)
+	cmd = append(cmd, []string{"-forward-dest", destSock}...)
-	cmd = append(cmd, []string{"-forward-user", "root"}...)
+	cmd = append(cmd, []string{"-forward-user", forwardUser}...)
 	cmd = append(cmd, []string{"-forward-identity", v.IdentityPath}...)
 	link := filepath.Join(filepath.Dir(filepath.Dir(socket)), "podman.sock")
 
@@ -1031,19 +1062,32 @@ func waitAndPingAPI(sock string) {
 	}
 }
 
-func printAPIForwardInstructions(forwardState apiForwardingState, forwardSock string) {
+func waitAPIAndPrintInfo(forwardState apiForwardingState, forwardSock string, rootFul bool, name string) {
 	if forwardState != noForwarding {
 		waitAndPingAPI(forwardSock)
+		if !rootFul {
+			fmt.Printf("\nThis machine is currently configured in rootless mode. If your containers\n")
+			fmt.Printf("require root permissions (e.g. ports < 1024), or if you run into compatibility\n")
+			fmt.Printf("issues with non-podman clients, you can switch using the following command: \n")
+
+			suffix := ""
+			if name != machine.DefaultMachineName {
+				suffix = " " + name
+			}
+			fmt.Printf("\n\tpodman machine set --rootful%s\n\n", suffix)
+		}
+
 		fmt.Printf("API forwarding listening on: %s\n", forwardSock)
 		if forwardState == dockerGlobal {
-			fmt.Printf("\nDocker API clients default to this address. You do not need to set DOCKER_HOST.\n\n")
+			fmt.Printf("Docker API clients default to this address. You do not need to set DOCKER_HOST.\n\n")
 		} else {
 			stillString := "still "
 			switch forwardState {
 			case notInstalled:
-				fmt.Printf("\nThe system helper service is not installed; the default Docker API socket address can't be used by podman.\n")
+				fmt.Printf("\nThe system helper service is not installed; the default Docker API socket\n")
+				fmt.Printf("address can't be used by podman. ")
 				if helper := findClaimHelper(); len(helper) > 0 {
-					fmt.Printf("If you would like to install it run the following command:\n")
+					fmt.Printf("If you would like to install it run the\nfollowing command:\n")
 					fmt.Printf("\n\tsudo %s install\n\n", helper)
 				}
 			case machineLocal:
@@ -1053,9 +1097,31 @@ func printAPIForwardInstructions(forwardState apiForwardingState, forwardSock st
 			default:
 				stillString = ""
 			}
-			fmt.Printf("You can %sconnect Docker API clients by setting DOCKER HOST using the\n", stillString)
+
+			fmt.Printf("You can %sconnect Docker API clients by setting DOCKER_HOST using the\n", stillString)
 			fmt.Printf("following command in your terminal session:\n")
 			fmt.Printf("\n\texport DOCKER_HOST='unix://%s'\n\n", forwardSock)
 		}
 	}
 }
+
+func (v *MachineVM) writeConfig() error {
+	// GetConfDir creates the directory so no need to check for
+	// its existence
+	vmConfigDir, err := machine.GetConfDir(vmtype)
+	if err != nil {
+		return err
+	}
+
+	jsonFile := filepath.Join(vmConfigDir, v.Name) + ".json"
+	// Write the JSON file
+	b, err := json.MarshalIndent(v, "", " ")
+	if err != nil {
+		return err
+	}
+	if err := ioutil.WriteFile(jsonFile, b, 0644); err != nil {
+		return err
+	}
+
+	return nil
+}

pkg/machine/wsl/machine.go

@@ -1,3 +1,4 @@
+//go:build windows
 // +build windows
 
 package wsl
@@ -8,6 +9,7 @@ import (
 	"fmt"
 	"io"
 	"io/ioutil"
+	"net/url"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -35,9 +37,6 @@ const (
 	ErrorSuccessRebootRequired  = 3010
 )
 
-// Usermode networking avoids potential nftables compatibility issues between the distro
-// and the WSL Kernel. Additionally it avoids fw rule conflicts between distros, since
-// all instances run under the same Kernel at runtime
 const containersConf = `[containers]
 
 [engine]
@@ -162,6 +161,8 @@ type MachineVM struct {
 	Port int
 	// RemoteUsername of the vm user
 	RemoteUsername string
+	// Whether this machine should run in a rootful or rootless manner
+	Rootful bool
 }
 
 type ExitCodeError struct {
@@ -227,12 +228,13 @@ func (v *MachineVM) Init(opts machine.InitOptions) (bool, error) {
 	homeDir := homedir.Get()
 	sshDir := filepath.Join(homeDir, ".ssh")
 	v.IdentityPath = filepath.Join(sshDir, v.Name)
+	v.Rootful = opts.Rootful
 
 	if err := downloadDistro(v, opts); err != nil {
 		return false, err
 	}
 
-	if err := writeJSON(v); err != nil {
+	if err := v.writeConfig(); err != nil {
 		return false, err
 	}
 
@@ -282,7 +284,7 @@ func downloadDistro(v *MachineVM, opts machine.InitOptions) error {
 	return machine.DownloadImage(dd)
 }
 
-func writeJSON(v *MachineVM) error {
+func (v *MachineVM) writeConfig() error {
 	vmConfigDir, err := machine.GetConfDir(vmtype)
 	if err != nil {
 		return err
@@ -302,14 +304,26 @@ func writeJSON(v *MachineVM) error {
 }
 
 func setupConnections(v *MachineVM, opts machine.InitOptions, sshDir string) error {
+	uri := machine.SSHRemoteConnection.MakeSSHURL("localhost", "/run/user/1000/podman/podman.sock", strconv.Itoa(v.Port), v.RemoteUsername)
 	uriRoot := machine.SSHRemoteConnection.MakeSSHURL("localhost", "/run/podman/podman.sock", strconv.Itoa(v.Port), "root")
-	if err := machine.AddConnection(&uriRoot, v.Name+"-root", filepath.Join(sshDir, v.Name), opts.IsDefault); err != nil {
+	identity := filepath.Join(sshDir, v.Name)
-		return err
+
+	uris := []url.URL{uri, uriRoot}
+	names := []string{v.Name, v.Name + "-root"}
+
+	// The first connection defined when connections is empty will become the default
+	// regardless of IsDefault, so order according to rootful
+	if opts.Rootful {
+		uris[0], names[0], uris[1], names[1] = uris[1], names[1], uris[0], names[0]
 	}
 
-	user := opts.Username
+	for i := 0; i < 2; i++ {
-	uri := machine.SSHRemoteConnection.MakeSSHURL("localhost", withUser("/run/[USER]/1000/podman/podman.sock", user), strconv.Itoa(v.Port), v.RemoteUsername)
+		if err := machine.AddConnection(&uris[i], names[i], identity, opts.IsDefault && i == 0); err != nil {
-	return machine.AddConnection(&uri, v.Name, filepath.Join(sshDir, v.Name), opts.IsDefault)
+			return err
+		}
+	}
+
+	return nil
 }
 
 func provisionWSLDist(v *MachineVM) (string, error) {
@@ -704,6 +718,30 @@ func pipeCmdPassThrough(name string, input string, arg ...string) error {
 	return cmd.Run()
 }
 
+func (v *MachineVM) Set(name string, opts machine.SetOptions) error {
+	if v.Rootful == opts.Rootful {
+		return nil
+	}
+
+	changeCon, err := machine.AnyConnectionDefault(v.Name, v.Name+"-root")
+	if err != nil {
+		return err
+	}
+
+	if changeCon {
+		newDefault := v.Name
+		if opts.Rootful {
+			newDefault += "-root"
+		}
+		if err := machine.ChangeDefault(newDefault); err != nil {
+			return err
+		}
+	}
+
+	v.Rootful = opts.Rootful
+	return v.writeConfig()
+}
+
 func (v *MachineVM) Start(name string, _ machine.StartOptions) error {
 	if v.isRunning() {
 		return errors.Errorf("%q is already running", name)
@@ -716,6 +754,18 @@ func (v *MachineVM) Start(name string, _ machine.StartOptions) error {
 		return errors.Wrap(err, "WSL bootstrap script failed")
 	}
 
+	if !v.Rootful {
+		fmt.Printf("\nThis machine is currently configured in rootless mode. If your containers\n")
+		fmt.Printf("require root permissions (e.g. ports < 1024), or if you run into compatibility\n")
+		fmt.Printf("issues with non-podman clients, you can switch using the following command: \n")
+
+		suffix := ""
+		if name != machine.DefaultMachineName {
+			suffix = " " + name
+		}
+		fmt.Printf("\n\tpodman machine set --rootful%s\n\n", suffix)
+	}
+
 	globalName, pipeName, err := launchWinProxy(v)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, "API forwarding for Docker API clients is not available due to the following startup failures.")