feat: Add users create and list commands (#1111)

This allows for *extremely basic* user management.

cli/usercreate.go

@@ -0,0 +1,90 @@
+package cli
+
+import (
+	"fmt"
+
+	"github.com/go-playground/validator/v10"
+	"github.com/spf13/cobra"
+	"golang.org/x/xerrors"
+
+	"github.com/coder/coder/cli/cliui"
+	"github.com/coder/coder/codersdk"
+	"github.com/coder/coder/cryptorand"
+)
+
+func userCreate() *cobra.Command {
+	var (
+		email    string
+		username string
+		password string
+	)
+	cmd := &cobra.Command{
+		Use: "create",
+		RunE: func(cmd *cobra.Command, args []string) error {
+			client, err := createClient(cmd)
+			if err != nil {
+				return err
+			}
+			organization, err := currentOrganization(cmd, client)
+			if err != nil {
+				return err
+			}
+			if username == "" {
+				username, err = cliui.Prompt(cmd, cliui.PromptOptions{
+					Text: "Username:",
+				})
+				if err != nil {
+					return err
+				}
+			}
+			if email == "" {
+				email, err = cliui.Prompt(cmd, cliui.PromptOptions{
+					Text: "Email:",
+					Validate: func(s string) error {
+						err := validator.New().Var(s, "email")
+						if err != nil {
+							return xerrors.New("That's not a valid email address!")
+						}
+						return err
+					},
+				})
+				if err != nil {
+					return err
+				}
+			}
+			if password == "" {
+				password, err = cryptorand.StringCharset(cryptorand.Human, 12)
+				if err != nil {
+					return err
+				}
+			}
+
+			_, err = client.CreateUser(cmd.Context(), codersdk.CreateUserRequest{
+				Email:          email,
+				Username:       username,
+				Password:       password,
+				OrganizationID: organization.ID,
+			})
+			if err != nil {
+				return err
+			}
+			_, _ = fmt.Fprintln(cmd.ErrOrStderr(), `A new user has been created!
+Share the instructions below to get them started.
+`+cliui.Styles.Placeholder.Render("—————————————————————————————————————————————————")+`
+Download the Coder command line for your operating system:
+https://github.com/coder/coder/releases
+
+Run `+cliui.Styles.Code.Render("coder login "+client.URL.String())+` to authenticate.
+
+Your email is: `+cliui.Styles.Field.Render(email)+`
+Your password is: `+cliui.Styles.Field.Render(password)+`
+
+Create a workspace  `+cliui.Styles.Code.Render("coder workspaces create")+`!`)
+			return nil
+		},
+	}
+	cmd.Flags().StringVarP(&email, "email", "e", "", "Specifies an email address for the new user.")
+	cmd.Flags().StringVarP(&username, "username", "u", "", "Specifies a username for the new user.")
+	cmd.Flags().StringVarP(&password, "password", "p", "", "Specifies a password for the new user.")
+	return cmd
+}