Merge ~laney/ubiquity:apt-update-oem into ubiquity:master

[Iain Lane]

gtk_ui, prepare: Run 'apt update' before installing OEM metapackages

We need to pick up any which might have been released after the ISO was
created.

LP: #1888241

[Dimitri John Ledkov (xnox)]

review: Approve (lgtm)

diff --git a/ubiquity/frontend/base.py b/ubiquity/frontend/base.py
index 0bbd152..1e89180 100644
--- a/ubiquity/frontend/base.py
+++ b/ubiquity/frontend/base.py
@@ -475,3 +475,6 @@ class BaseFrontend:
 
     def set_online_state(self, state):
         pass
+
+    def save_oem_metapackages_list(self, wait_finished=False):
+        pass
diff --git a/ubiquity/frontend/gtk_ui.py b/ubiquity/frontend/gtk_ui.py
index 8da7e5c..52f8c17 100644
--- a/ubiquity/frontend/gtk_ui.py
+++ b/ubiquity/frontend/gtk_ui.py
@@ -255,6 +255,7 @@ class Wizard(BaseFrontend):
         self.screen_reader = False
         self.orca_process = None
         self.a11y_settings = None
+        self.have_apt_updated = False
 
         # To get a "busy mouse":
         self.watch = Gdk.Cursor.new(Gdk.CursorType.WATCH)
@@ -406,8 +407,47 @@ class Wizard(BaseFrontend):
                 ['canberra-gtk-play', '--id=system-ready'],
                 preexec_fn=misc.drop_all_privileges)
 
+        self.save_oem_metapackages_list()
+
+    def save_oem_metapackages_list(self, wait_finished=False):
+        ''' If we can, update the apt indexes. Then run 'ubuntu-drivers
+        list-oem' to find any OEM metapackages for this system. If we've
+        already done this with updated apt indexes before, there's no point
+        running again, so just return. '''
+
+        # We already did it
+        if self.have_apt_updated:
+            syslog.syslog(syslog.LOG_INFO, 'We\'ve already apt updated and '
+                          'run, not doing so again.')
+            return
+
         with misc.raised_privileges():
+            try:
+                import apt
+                syslog.syslog(syslog.LOG_INFO, 'Trying to update apt indexes '
+                              'to run ubuntu-drivers against fresh data.')
+                cache = apt.cache.Cache()
+                cache.update()
+                cache.open()
+                self.have_apt_updated = True
+            except apt.cache.FetchFailedException:
+                syslog.syslog(syslog.LOG_INFO,
+                              'Failed to update apt indexes; offline? '
+                              'Continuing without.')
+            except apt.cache.LockFailedException:
+                syslog.syslog(syslog.LOG_WARNING,
+                              'Failed to update apt indexes, permission '
+                              'denied: running under test?')
+
             if osextras.find_on_path('ubuntu-drivers'):
+                # We already ran, were offline then, and are still offline, no
+                # point running again.
+                if os.path.exists('/run/ubuntu-drivers-oem.autoinstall') and \
+                        not self.have_apt_updated:
+                    return
+
+                # It's either the first run or a subsequent one but we now
+                # managed to update the apt indexes.
                 self.ubuntu_drivers = subprocess.Popen(
                     ['ubuntu-drivers',
                      'list-oem',
@@ -417,6 +457,10 @@ class Wizard(BaseFrontend):
                     stdout=subprocess.PIPE,
                     stderr=subprocess.DEVNULL)
 
+                if wait_finished:
+                    self.ubuntu_drivers.communicate()
+                    self.ubuntu_drivers = None
+
     def all_children(self, parent):
         if isinstance(parent, Gtk.Container):
             def recurse(x, y):
diff --git a/ubiquity/plugins/ubi-prepare.py b/ubiquity/plugins/ubi-prepare.py
index af3b4d0..29392d6 100644
--- a/ubiquity/plugins/ubi-prepare.py
+++ b/ubiquity/plugins/ubi-prepare.py
@@ -462,7 +462,15 @@ class Page(plugin.Plugin):
             with open('/run/ubuntu-drivers-oem.autoinstall', 'r') as f:
                 syslog.syslog(F'ubuntu-drivers list-oem finished with: "{" ".join(f.read().splitlines())}"')
         except FileNotFoundError:
-            syslog.syslog('ubuntu-drivers list-oem finished with no available packages')
+            syslog.syslog('ubuntu-drivers list-oem finished with no available packages. Maybe we need to apt update? '
+                          'Doing that and trying again.')
+            # We only do this when we really have to since it could be slow: apt update & re-run of ubuntu-drivers
+            self.frontend.save_oem_metapackages_list(wait_finished=True)
+            try:
+                with open('/run/ubuntu-drivers-oem.autoinstall', 'r') as f:
+                    syslog.syslog(F'ubuntu-drivers list-oem finished with: "{" ".join(f.read().splitlines())}"')
+            except FileNotFoundError:
+                syslog.syslog('No, we didn\'t find any OEM packages again.')
 
         if self.should_show_rst_page():
             if not self.ui.show_rst_page():