unattended: Add option to set the user-login

Let's allow setting the login of the guest user.

Using the user from the system is a quite good fallback, but would break
unattended installations when running virt-install as root. Thus, for
those cases, it makes sense to have the option of setting the user
login.

Signed-off-by: Fabiano Fidêncio <fidencio@redhat.com>

man/virt-install.pod

@@ -628,12 +628,18 @@ password-file.
 Note that only the first line of the file will be considered, including
 any whitespace characters and excluding new-line.
 
+=item B<user-login=>
+
+The user login name to be used in th VM. virt-install will default to your
+current host username if this is unspecified.
+
 =item B<user-password-file=>
 
 A file used to set the VM user password. This option can be used either as
 "user-password-file=/path/to/password-file" or as
 "user-password-file=/dev/fd/n", being n the file descriptor of the
-password-file. The username is your current host username.
+password-file. The username is either the user-login specified or your current
+host username.
 Note that only the first line of the file will be considered, including
 any whitespace characters and excluding new-line.
 

tests/clitest.py

@@ -887,7 +887,7 @@ c.add_valid("--connect %s --pxe --disk size=1" % utils.URIs.test_defaultpool_col
 ####################
 
 c = vinst.add_category("unattended-install", "--connect %(URI-KVM)s --nographics --noautoconsole --disk none", prerun_check=no_osinfo_unattend_cb)
-c.add_compare("--install fedora26 --unattended profile=desktop,admin-password-file=%(ADMIN-PASSWORD-FILE)s,user-password-file=%(USER-PASSWORD-FILE)s,product-key=1234", "osinfo-url-unattended", prerun_check=lambda: not unattended.OSInstallScript.have_libosinfo_installation_url())  # unattended install for fedora, using initrd injection
+c.add_compare("--install fedora26 --unattended profile=desktop,admin-password-file=%(ADMIN-PASSWORD-FILE)s,user-password-file=%(USER-PASSWORD-FILE)s,product-key=1234,user-login=foobar", "osinfo-url-unattended", prerun_check=lambda: not unattended.OSInstallScript.have_libosinfo_installation_url())  # unattended install for fedora, using initrd injection
 c.add_compare("--cdrom %(ISO-WIN7)s --unattended profile=desktop,admin-password-file=%(ADMIN-PASSWORD-FILE)s", "osinfo-win7-unattended", prerun_check=no_osinfo_unattended_win_drivers_cb)  # unattended install for win7
 c.add_compare("--os-variant fedora26 --unattended profile=jeos,admin-password-file=%(ADMIN-PASSWORD-FILE)s --location %(ISO-F26-NETINST)s", "osinfo-netinst-unattended")  # triggering the special netinst checking code
 c.add_compare("--os-variant silverblue29 --location http://example.com", "network-install-resources")  # triggering network-install resources override

virtinst/cli.py

@@ -1514,6 +1514,7 @@ class ParserUnattended(VirtCLIParser):
         VirtCLIParser._init_class(**kwargs)
         cls.add_arg("profile", "profile")
         cls.add_arg("admin-password-file", "admin_password_file")
+        cls.add_arg("user-login", "user_login")
         cls.add_arg("user-password-file", "user_password_file")
         cls.add_arg("product-key", "product_key")
 

virtinst/install/unattended.py

@@ -36,9 +36,14 @@ def _make_installconfig(script, osobj, unattended_data, arch, hostname, url):
 
     config = Libosinfo.InstallConfig()
 
-    # Set user login and name based on the one from the system
-    config.set_user_login(getpass.getuser())
-    config.set_user_realname(pwd.getpwnam(getpass.getuser()).pw_gecos)
+    # Set user login and name
+    # In case it's specified via command-line, use the specified one as login
+    # and realname. Otherwise, fallback fto the one from the system
+    login = unattended_data.user_login or getpass.getuser()
+    login = login.lower()
+    realname = unattended_data.user_login or pwd.getpwnam(login).pw_gecos
+    config.set_user_login(login)
+    config.set_user_realname(realname)
 
     # Set user-password.
     # In case it's required and not passed, just raise a RuntimeError.
@@ -252,6 +257,7 @@ class OSInstallScript:
 class UnattendedData():
     profile = None
     admin_password_file = None
+    user_login = None
     user_password_file = None
     product_key = None