installation-scripting: rework step tracking

src/util/installation_scripting.py

@@ -25,78 +25,92 @@ class InstallationScripting():
     * Configuration. Configures an OS according to user's choices.
     '''
 
-    terminal = Vte.Terminal()
-    cancel = Gio.Cancellable()
-
-    lock = Lock()
-    current_step = Step.none
-    step_ready = Step.none
-    script_running = False
-
     def __init__(self):
-        # setup terminal
-        self.terminal.set_input_enabled(False)
-        self.terminal.set_scroll_on_output(True)
-        self.terminal.set_hexpand(True)
-        self.terminal.set_vexpand(True)
-        self.terminal.connect('child-exited', self._on_child_exited)
+        self.terminal = self._setup_terminal()
+        self.cancel = Gio.Cancellable()
 
-    def _start_next_script(self):
-        if self.current_step is Step.configure:
-            global_state.installation_running = False
-            global_state.advance(None, allow_return=False)
+        self.lock = Lock()
+        self.ready_step = Step.none
+        self.running_step = Step.none
+        self.finished_step = Step.none
 
-        if self.current_step.value < self.step_ready.value and not self.script_running:
-            self.current_step = Step(self.current_step.value + 1)
-            print(f'Starting step "{self.current_step.name}"...')
+    def _setup_terminal(self):
+        terminal = Vte.Terminal()
+        terminal.set_input_enabled(False)
+        terminal.set_scroll_on_output(True)
+        terminal.set_hexpand(True)
+        terminal.set_vexpand(True)
+        terminal.connect('child-exited', self._on_child_exited)
+        return terminal
 
-            is_installing = self.current_step is Step.install or self.current_step is Step.configure
-            is_configuring = self.current_step is Step.configure
-            envs = global_state.create_envs(is_installing, is_configuring)
+    def _try_start_next_script(self):
+        if self.running_step != Step.none:
+            return
 
-            global_state.installation_running = is_installing
+        if self.finished_step.value >= self.ready_step.value:
+            return
 
-            # check config
-            if envs == None:
-                print(f'Not all config options set for "{self.current_step.name}". Please report this bug.')
-                print('############################')
-                print(global_state.config)
-                print('############################')
-                global_state.installation_failed()
-                return
+        next_step = Step(self.finished_step.value + 1)
+        print(f'Starting step "{next_step.name}"...')
 
-            # start script
-            file_name = f'/etc/os-installer/scripts/{self.current_step.name}.sh'
-            if os.path.exists(file_name):
-                self.script_running, _ = self.terminal.spawn_sync(
-                    Vte.PtyFlags.DEFAULT, '/', ['sh', file_name],
-                    envs, GLib.SpawnFlags.DEFAULT, None, None, self.cancel)
-                if not self.script_running:
-                    print(f'Could not start {self.current_step.name} script! Ignoring.')
-                    self._start_next_script()
+        with_install_env = next_step is Step.install or next_step is Step.configure
+        with_configure_env = next_step is Step.configure
+        envs = global_state.create_envs(with_install_env, with_configure_env)
+
+        # check config
+        if envs == None:
+            print(f'Not all config options set for "{next_step.name}". '
+                  'Please report this bug.')
+            print('############################')
+            print(global_state.config)
+            print('############################')
+            global_state.installation_failed()
+            return
+
+        # start script
+        file_name = f'/etc/os-installer/scripts/{next_step.name}.sh'
+        if os.path.exists(file_name):
+            started_script, _ = self.terminal.spawn_sync(
+                Vte.PtyFlags.DEFAULT, '/', ['sh', file_name],
+                envs, GLib.SpawnFlags.DEFAULT, None, None, self.cancel)
+            if not started_script:
+                print(f'Could not start {self.finished_step.name} script! '
+                      'Ignoring.')
+                self._try_start_next_script()
             else:
-                print(f'No script for step {self.current_step.name} exists.')
-                self._start_next_script()
+                self.running_step = next_step
+        else:
+            print(f'No script for step {next_step.name} exists.')
+            self.finished_step = next_step
+            self._try_start_next_script()
 
     ### callbacks ###
 
     def _on_child_exited(self, terminal, status):
         with self.lock:
-            self.script_running = False
-            print(f'Finished step "{self.current_step.name}".')
+            self.finished_step = self.running_step
+            self.running_step = Step.none
 
             if not status == 0 and not global_state.demo_mode:
+                print(f'Failure during step "{self.finished_step.name}"')
                 global_state.installation_failed()
+                return
+
+            print(f'Finished step "{self.finished_step.name}".')
+
+            if self.finished_step is Step.configure:
+                global_state.installation_running = False
+                global_state.advance(None, allow_return=False)
             else:
-                self._start_next_script()
+                self._try_start_next_script()
 
     ### public methods ###
 
     def set_ok_to_start_step(self, step: Step):
         with self.lock:
-            if self.step_ready.value < step.value:
-                self.step_ready = step
-                self._start_next_script()
+            if self.ready_step.value < step.value:
+                self.ready_step = step
+                self._try_start_next_script()
 
 
 installation_scripting = InstallationScripting()