Hi,
With UC20, you can declare snaps in a model assertion using the following snaps syntax:
"base": "core20",
"snaps":
[
{
"name": "test-pc",
"type": "gadget"
},
{
"default-channel": "20/beta",
"id": "pYVQrBcKmBa0mZ4CCN7ExT6jH8rY1hza",
"name": "pc-kernel",
"type": "kernel"
},
{
"default-channel": "latest/beta",
"id": "DLqre5XGLbDqg9jPtiAhRRjDuPVa5X1q",
"name": "core20",
"type": "base"
},
{
"default-channel": "latest/beta",
"id": "PMrrV4ml8uWuEUDBT8dSGnKUYbevVhc4",
"name": "snapd",
"type": "snapd"
},
…and everything works fine. I can create the model assertion and then the image.
In the smae document, if I then declare another snap that uses base core18, when I try to build it ubuntu-image complains that the base core18 is not included in the model assertion. If I then add core18 as another entry in the snaps list, like this:
{
"default-channel": "latest/stable",
"id": "CSO04Jhav2yK0uz97cr0ipQRyqg0qQL6",
"name": "core18",
"type": "base"
},
…it will build ok, but on first boot the installation process fails with an error:
the-tool[258]: error: cannot load metadata and verify essential bootstrap snaps [base kernel snapd]: model does not specify all the requested essential snaps: [base kernel snapd]
So, even though the model assertion document already has a dedicated base variable that specifies core20 is the base, the additional base snap in the image seems to confuse things and breaks the install/setup process.
The only way I can successfully create an image and a working installation without error, is to specify both the app snap and the extra base snap using the --snap argument for each snap when calling the ubuntu-image utility.
It seems strange that in this situation I can’t include all the snap components of the image in the model assertion directly - that should be the document the fully describes the image.
Am I missing something here ?
What is the recommended way of working with this scenario ?
Have I simply found a bug ? [ will happily raise one if so ]
Cheers,
Just
