Fix curtin install error detection and presentation

When curtin encountered an error, if the resulting message
was very large, this would prevent the progress screen from
displaying useful information and left the user believing the
install was still going on even when it had stopped.

Resolve this by applying some post processing on the curtin
error message to help user better spot the issue.  We also
update the Title, Header and Footer to indicate an error has
occurred.

Finally, left-align the progress output.

Signed-off-by: Ryan Harper <ryan.harper@canonical.com>

subiquity/controllers/installprogress.py

@@ -40,6 +40,7 @@ class InstallProgressController(ControllerPolicy):
         self.install_log = None
 
         # state flags
+        self.install_error = False
         self.install_config = False
         self.install_spawned = False
         self.install_complete = False
@@ -60,6 +61,36 @@ class InstallProgressController(ControllerPolicy):
                   self.postinstall_complete))
         return (self.install_complete and self.postinstall_complete)
 
+    def curtin_tail_install_log(self):
+        if os.path.exists(self.install_log):
+            tail_cmd = ['tail', '-n', '10', self.install_log]
+            log.debug('tail cmd: {}'.format(" ".join(tail_cmd)))
+            install_tail = subprocess.check_output(tail_cmd)
+            return install_tail
+        else:
+            log.debug(('Install log not yet present:') +
+                      '{}'.format(self.install_log))
+
+        return ''
+
+    def curtin_error(self):
+        log.debug('curtin_error')
+        # just the last ten lines
+        errmsg = self.curtin_tail_install_log()[-800:].decode('utf-8')
+        # Holy Unescaping Batman!
+        errmsg = errmsg.replace("\\\'", "")
+        errmsg = errmsg.replace("\'\'", "")
+        errmsg = errmsg.replace("\\n\'\n", "\n")
+        errmsg = errmsg.replace('\\n', '\n')
+        log.error(errmsg)
+        title = ('An error occurred during installation')
+        self.ui.set_header(title, 'Please report this error in Launchpad')
+        self.progress_view.text.set_text(errmsg)
+        self.ui.set_footer("An error as occurred.", 100)
+        self.progress_view.show_finished_button()
+        log.debug('curtin_error: refreshing final error screen')
+        self.signal.emit_signal('refresh')
+
     @coroutine
     def curtin_install(self):
         log.debug('Curtin Install: calling curtin with '
@@ -83,12 +114,17 @@ class InstallProgressController(ControllerPolicy):
 
         log.debug('Curtin install cmd: {}'.format(curtin_cmd))
         result = yield utils.run_command_async(" ".join(curtin_cmd))
+        log.debug('curtin_install: result: {}'.format(result))
         if result['status'] > 0:
             msg = ("Problem with curtin "
                    "install: {}".format(result))
             log.error(msg)
-            self.progress_view.text.set_text(msg)
-            self.loop.remove_alarm(self.alarm)
+            # stop the update and clear the screen
+            self.install_error = True
+            log.debug('curtin_install: clearing screen')
+            self.progress_view.text.set_text('')
+            self.signal.emit_signal('refresh')
+            return
         log.debug('After curtin install OK')
         self.install_complete = True
 
@@ -119,14 +155,25 @@ class InstallProgressController(ControllerPolicy):
         result = yield utils.run_command_async(" ".join(curtin_cmd))
         if result['status'] > 0:
             msg = ("Problem with curtin "
-                   "install: {}".format(result))
+                   "post-install: {}".format(result))
             log.error(msg)
-            self.progress_view.text.set_text(msg)
-            self.loop.remove_alarm(self.alarm)
+            # stop the update and clear the screen
+            self.install_error = True
+            log.debug('curtin_postinstall: clearing screen')
+            self.progress_view.text.set_text('')
+            self.signal.emit_signal('refresh')
+            return
+        log.debug('After curtin postinstall OK')
         self.postinstall_complete = True
 
     def progress_indicator(self, *args, **kwargs):
+        log.debug('progress_indicator')
+        if self.install_error:
+            log.debug('progress_indicator: error detected')
+            self.curtin_error()
+            return
         if self.is_complete:
+            log.debug('progress_indicator: complete!')
             self.progress_view.text.set_text("Finished install!")
             self.ui.set_footer("", 100)
             self.progress_view.show_finished_button()
@@ -138,16 +185,13 @@ class InstallProgressController(ControllerPolicy):
             # kick off postinstall
             self.signal.emit_signal('installprogress:curtin-postinstall')
         else:
-            if os.path.exists(self.install_log):
-                tail_cmd = ['tail', '-n', '10', self.install_log]
-                log.debug('tail cmd: {}'.format(" ".join(tail_cmd)))
-                install_tail = subprocess.check_output(tail_cmd)
-                self.progress_view.text.set_text(install_tail)
-            else:
-                log.debug(('Install log not yet present:') +
-                          '{}'.format(self.install_log))
+            log.debug('progress_indicator: looping')
+            install_tail = self.curtin_tail_install_log()
+            self.progress_view.text.set_text(install_tail)
 
-        self.alarm = self.loop.set_alarm_in(0.3, self.progress_indicator)
+        if not self.install_error:
+            log.debug('progress_indicator: setting alarm')
+            self.alarm = self.loop.set_alarm_in(0.3, self.progress_indicator)
 
     def reboot(self):
         if self.opts.dry_run:

subiquity/ui/views/installprogress.py

@@ -30,7 +30,7 @@ class ProgressView(ViewPolicy):
         """
         self.model = model
         self.signal = signal
-        self.text = Text("Wait for it ...", align="center")
+        self.text = Text("Wait for it ...", align="left")
         self.body = [
             Padding.center_79(self.text),
             Padding.line_break(""),