Add: allow steps to run someting even if they're skipped

The debootstrap step now runs 'apt-get update' even if the step is
otherwise skipped. This allows a chroot unpacked from an old tarball
to get up-to-date Packages files.

3 files changed, 20 insertions, 2 deletions

diff --git a/vmdb/app.py b/vmdb/app.py
index 3a88bba..fb28145 100644
--- a/vmdb/app.py
+++ b/vmdb/app.py
@@ -84,15 +84,26 @@ class Vmdb2(cliapp.Application):
         core_meltdown = False
         steps_taken = []
 
+        even_if_skipped = method_name + '_even_if_skipped'
         for step in steps:
             try:
                 logging.info(msg, step)
                 steps_taken.append(step)
                 runner = self.step_runners.find(step)
                 if runner.skip(step, self.settings, state):
-                    logging.info('Skipping as requested')
+                    logging.info('Skipping as requested by unless')
+                    method_names = [even_if_skipped]
                 else:
-                    method = getattr(runner, method_name)
+                    method_names = [method_name, even_if_skipped]
+
+                methods = [
+                    getattr(runner, name)
+                    for name in method_names
+                    if hasattr(runner, name)
+                ]
+
+                for method in methods:
+                    logging.info('Calling {}'.format(method))
                     method(step, self.settings, state)
             except BaseException as e:
                 vmdb.error(str(e))
diff --git a/vmdb/plugins/debootstrap_plugin.py b/vmdb/plugins/debootstrap_plugin.py
index 91fc8d1..f52f718 100644
--- a/vmdb/plugins/debootstrap_plugin.py
+++ b/vmdb/plugins/debootstrap_plugin.py
@@ -42,4 +42,8 @@ class DebootstrapStepRunner(vmdb.StepRunnerInterface):
         if not (suite and tag and target and mirror):
             raise Exception('missing arg for debootstrap step')
         vmdb.runcmd(['debootstrap', '--variant', variant, suite, target, mirror])
+
+    def run_even_if_skipped(self, step, settings, state):
+        tag = step['target']
+        target = state.tags.get_mount_point(tag)
         vmdb.runcmd_chroot(target, ['apt-get', 'update'])
diff --git a/vmdb/step_list.py b/vmdb/step_list.py
index 1f29072..b8f55f4 100644
--- a/vmdb/step_list.py
+++ b/vmdb/step_list.py
@@ -27,6 +27,9 @@ class StepRunnerInterface(object):  # pragma: no cover
     def run(self, step_spec, settings, state):
         raise NotImplementedError()
 
+    def run_even_if_skipped(self, step_spec, settings, state):
+        pass
+
     def teardown(self, step_spec, settings, state):
         # Default implementation does nop, so that sub-classes don't
         # need to have a nop teardown.