Install cmd: add user setup + cobra cmd

Signed-off-by: Karen Almog <kalmog@mirantis.com>

.gitignore

@@ -5,6 +5,7 @@ bindata
 .*.stamp
 .tmp
 .terraform
+.idea
 *.tfstate*
 aws_private.pem
 out.json

cmd/install.go

@@ -0,0 +1,83 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"reflect"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+	"github.com/spf13/cobra"
+
+	"github.com/k0sproject/k0s/pkg/apis/v1beta1"
+	"github.com/k0sproject/k0s/pkg/install"
+)
+
+func init() {
+	installCmd.Flags().StringVar(&role, "role", "server", "node role (possible values: server or worker. In a single-node setup, a worker role should be used)")
+}
+
+var (
+	role string
+
+	installCmd = &cobra.Command{
+		Use:   "install",
+		Short: "Helper command for setting up k0s on a brand-new system. Must be run as root (or with sudo)",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			switch role {
+			case "server", "worker":
+				return setup()
+			default:
+				logrus.Errorf("invalid value %s for install role", role)
+				return cmd.Help()
+			}
+		},
+	}
+)
+
+// the setup functions:
+// * Ensures that the proper users are created
+// * sets up startup and logging for k0s
+func setup() error {
+	if os.Geteuid() != 0 {
+		logrus.Fatal("this command must be run as root!")
+	}
+
+	if role == "server" {
+		if err := createServerUsers(); err != nil {
+			logrus.Errorf("failed to create server users: %v", err)
+		}
+	}
+
+	return nil
+}
+
+func createServerUsers() error {
+	clusterConfig, err := ConfigFromYaml(cfgFile)
+	if err != nil {
+		return err
+	}
+	users := getUserList(*clusterConfig.Install.SystemUsers)
+
+	var messages []string
+	for _, v := range users {
+		if err := install.EnsureUser(v, k0sVars.DataDir); err != nil {
+			messages = append(messages, err.Error())
+		}
+	}
+
+	if len(messages) > 0 {
+		return fmt.Errorf(strings.Join(messages, "\n"))
+	}
+	return nil
+}
+
+func getUserList(sysUsers v1beta1.SystemUser) []string {
+	v := reflect.ValueOf(sysUsers)
+	values := make([]string, v.NumField())
+
+	for i := 0; i < v.NumField(); i++ {
+		values[i] = v.Field(i).String()
+	}
+	return values
+}

cmd/root.go

@@ -57,6 +57,7 @@ func init() {
 	rootCmd.AddCommand(etcdCmd)
 	rootCmd.AddCommand(docs)
 	rootCmd.AddCommand(userCmd)
+	rootCmd.AddCommand(installCmd)
 
 	longDesc = "k0s - The zero friction Kubernetes - https://k0sproject.io"
 	if build.EulaNotice != "" {

cmd/token.go

@@ -79,7 +79,7 @@ users:
 		Use:   "token",
 		Short: "Manage join tokens",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return nil
+			return tokenCreateCmd.Usage()
 		},
 	}
 

cmd/user.go

@@ -49,10 +49,11 @@ users:
 
 	// userCmd creates new certs and kubeConfig for a user
 	userCmd = &cobra.Command{
-		Use:   "user",
+		Use:   "user [command]",
 		Short: "Manage user access",
 		RunE: func(cmd *cobra.Command, args []string) error {
-			return nil
+			// user command does nothing
+			return userCreateCmd.Usage()
 		},
 	}
 

internal/util/file.go

@@ -18,12 +18,13 @@ package util
 import (
 	"fmt"
 	"os"
+	"os/exec"
 )
 
 // FileExists checks if a file exists and is not a directory before we
 // try using it to prevent further errors.
-func FileExists(filename string) bool {
-	info, err := os.Stat(filename)
+func FileExists(fileName string) bool {
+	info, err := os.Stat(fileName)
 	if os.IsNotExist(err) {
 		return false
 	}
@@ -42,3 +43,13 @@ func CheckPathPermissions(path string, perm os.FileMode) error {
 	}
 	return nil
 }
+
+// Find the path for a given file (similar to `which`)
+func GetExecPath(fileName string) (*string, error) {
+	path, err := exec.LookPath(fileName)
+	if err != nil {
+		return nil, err
+	}
+
+	return &path, nil
+}

internal/util/users.go

@@ -37,3 +37,26 @@ func GetGID(name string) (int, error) {
 	}
 	return strconv.Atoi(entry.Gid)
 }
+
+func CheckIfUserExists(name string) (bool, error) {
+	_, err := user.Lookup(name)
+	if _, ok := err.(user.UnknownUserError); ok {
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	return true, nil
+}
+
+/*
+func GetLinuxDist() (string, error) {
+	if runtime.GOOS == "windows" {
+		return "", fmt.Errorf("unsupported OS")
+	}
+	cfg, err := ini.Load("/etc/os-release")
+	if err != nil {
+		fmt.Printf("failed to read file: %v", err)
+	}
+	return cfg.Section("").Key("ID").String(), nil
+}*/

pkg/install/users.go

@@ -0,0 +1,87 @@
+package install
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"os/user"
+	"strings"
+
+	"github.com/sirupsen/logrus"
+
+	"github.com/k0sproject/k0s/internal/util"
+)
+
+// EnsureUser checks if a user exists, and creates it, if it doesn't
+// TODO: we should also consider modifying the user, if the user exists, but with wrong settings
+func EnsureUser(name string, homeDir string) error {
+	shell, err := util.GetExecPath("nologin")
+	if err != nil {
+		return err
+	}
+
+	exists, err := util.CheckIfUserExists(name)
+	// User doesn't exist
+	if !exists && err == nil {
+		// Create the User
+		if err := CreateUser(name, homeDir, *shell); err != nil {
+			return err
+		}
+		// User perhaps exists, but cannot be fetched
+	} else if err != nil {
+		return err
+	}
+	// verify that user can be fetched, and exists
+	_, err = user.Lookup(name)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// CreateUser creates a system user with either `adduser` or `useradd` command
+func CreateUser(userName string, homeDir string, shell string) error {
+	var userCmd string
+	var userCmdArgs []string
+
+	logrus.Infof("creating user: %s", userName)
+	_, err := util.GetExecPath("useradd")
+	if err == nil {
+		userCmd = "useradd"
+		userCmdArgs = []string{`--home`, homeDir, `--shell`, shell, `--system`, userName}
+	} else {
+		userCmd = "adduser"
+		userCmdArgs = []string{`--disabled-password`, `--gecos`, `""`, `--home`, homeDir, `--shell`, shell, `--system`, userName}
+	}
+
+	cmd := exec.Command(userCmd, userCmdArgs...)
+	if err := execCmd(cmd); err != nil {
+		return err
+	}
+	return nil
+}
+
+// cmd wrapper
+func execCmd(cmd *exec.Cmd) error {
+	logrus.Debugf("executing command: %v", quoteCmd(cmd))
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+
+	if err := cmd.Run(); err != nil {
+		return fmt.Errorf("failed to run command %s: %v", quoteCmd(cmd), err)
+	}
+	return nil
+}
+
+// parse a cmd struct to string
+func quoteCmd(cmd *exec.Cmd) string {
+	if len(cmd.Args) == 0 {
+		return fmt.Sprintf("%q", cmd.Path)
+	}
+
+	var q []string
+	for _, s := range cmd.Args {
+		q = append(q, fmt.Sprintf("%q", s))
+	}
+	return strings.Join(q, ` `)
+}