Code review comment for ~d0ugal/maas-images:release-notifications

The "1" in "com.ubuntu.maas:candidate:1:maas-notification" can be used as your version. Its up to you if you want a specific field.

It looks like our existing mirroring tools require the file field, and it must be valid. If I generate a stream and try to mirror it the SimpleStreams mirroring tool chokes. sstream-mirror is Canonical's standard mirroring tool[1] which goes back at least to Precise. Unfortinetly that means this stream must work with the tool as is.

$ ./bin/meph2-import conf/release-notifications.yaml /tmp/test
$ $ sstream-mirror /tmp/test/ /tmp/mirror
+ com.ubuntu.maas:candidate:1:maas-notification 20200921.0 release_notification release-notifications/20200921.0/release-notification.yaml 0 Mb
0 Mb change
Traceback (most recent call last):
  File "/usr/bin/sstream-mirror", line 157, in <module>
    main()
  File "/usr/bin/sstream-mirror", line 153, in main
    tmirror.sync(smirror, initial_path)
  File "/usr/lib/python3/dist-packages/simplestreams/mirrors/__init__.py", line 91, in sync
    return self.sync_index(reader, path, data, content)
  File "/usr/lib/python3/dist-packages/simplestreams/mirrors/__init__.py", line 254, in sync_index
    self.sync(reader, path=epath)
  File "/usr/lib/python3/dist-packages/simplestreams/mirrors/__init__.py", line 89, in sync
    return self.sync_products(reader, path, data, content)
  File "/usr/lib/python3/dist-packages/simplestreams/mirrors/__init__.py", line 355, in sync_products
    self.insert_item(item, src, target, pgree, ipath_cs)
  File "/usr/lib/python3/dist-packages/simplestreams/mirrors/__init__.py", line 490, in insert_item
    self.store.insert(data['path'], contentsource,
  File "/usr/lib/python3/dist-packages/simplestreams/objectstores/__init__.py", line 142, in insert
    buf = reader.read(self.read_size)
  File "/usr/lib/python3/dist-packages/simplestreams/contentsource.py", line 275, in read
    buf = self.cs.read(size)
  File "/usr/lib/python3/dist-packages/simplestreams/contentsource.py", line 135, in read
    self.open()
  File "/usr/lib/python3/dist-packages/simplestreams/contentsource.py", line 131, in open
    self.fd = self._open()
  File "/usr/lib/python3/dist-packages/simplestreams/contentsource.py", line 127, in _open
    raise myerr
OSError: Unable to open /tmp/test/release-notifications/20200921.0/release-notification.yaml. mirrors=[]

[1] https://maas.io/docs/local-image-mirror