New import script dumps traceback for any config file errors

[Graham Binns]

If something essential is missing from its config file, the new import script errors thusly:

2014-04-01 17:17:37,019 ERROR Unhandled exception; unable to continue.
Traceback (most recent call last):
  File "/home/graham/workspace/maas-work/maas/scripts/maas-import-pxe-files", line 29, in <module>
    main(args)
  File "/home/graham/workspace/maas-work/maas/src/provisioningserver/import_images/boot_resources.py", line 485, in main
    repo_boot = dumper.dump(source['path'], keyring=source['keyring'])
  File "/home/graham/workspace/maas-work/maas/src/provisioningserver/import_images/boot_resources.py", line 264, in dump
    super(RepoDumper, self).sync(reader, rpath)
  File "/usr/lib/python2.7/dist-packages/simplestreams/mirrors/__init__.py", line 88, in sync
    return self.sync_index(reader, path, data, content)
  File "/usr/lib/python2.7/dist-packages/simplestreams/mirrors/__init__.py", line 240, in sync_index
    self.sync(reader, path=epath)
  File "/usr/lib/python2.7/dist-packages/simplestreams/mirrors/__init__.py", line 86, in sync
    return self.sync_products(reader, path, data, content)
  File "/usr/lib/python2.7/dist-packages/simplestreams/mirrors/__init__.py", line 318, in sync_products
    self.insert_item(item, src, target, pgree, ipath_cs)
  File "/home/graham/workspace/maas-work/maas/src/provisioningserver/import_images/boot_resources.py", line 277, in insert_item
    arch, subarches = item['arch'], item['subarches']
KeyError: u'subarches'

This is inelegant and unhelpful. It would be neater – and more useful – to say something like:

 "Missing required config item 'subarches'."

Bonus points for providing the user with a description of what the subarches config item should look like in an ideal world.

[Julian Edwards (julian-edwards)]

I could have sworn I already filed a bug and a kanban card for this, but I failed to find either.

[Julian Edwards (julian-edwards)]

Also it's not just missing config items, it's *any* parsing error on the config.

[Launchpad Janitor (janitor)]

[Expired for MAAS because there has been no activity for 60 days.]