kernel options not showing up in WebUI and not being passed at install time to one node

[Liam Young]

I have a Global Kernel Parameter set but one of my nodes its not showing it in the WebUI (it shows for all other nodes). Also it doesn't seem to be being passed when the node installs or boots subsequently.

All nodes are in the "ready" state

I've tried removing the kernel option and adding it back in again

maas-cli seems to returns the correct value
 $ maas-cli maas maas get-config name=kernel_opts
 "console=ttyS1"

[Gavin Panella (allenap)]

If there's a tag associated with the node that specifies kernel opts, it takes precedence over the global options. Could that be happening here? A tag that used to have kernel options set but which you removed? (This latter scenario seems probable; the Tag.kernel_opts field is defined as being blank or null, but the query for effective kernel options only considers nullness.)

Fwiw, if more than one tag with kernel options applies to a node, only the first tag, when sorted by name in lexicographical order, with kernel options is used.

[Liam Young (gnuoy)]

Listing the tags does indeed show that the tag associated with the machine I was having problems with has an empty string for kernel_opts rather than None. Removing the tag associated with the machine has caused the global kernel parameters to reappear.

So, the bug seems to be that using the cli to create new tags without specifying kernel options results in Tag.kernel_opts being an empty string rather than none:

maas-cli maas tags new name="Bob" comment="Short Legs"
{
    "comment": "Short Legs",
    "definition": "",
    "resource_uri": "/MAAS/api/1.0/tags/Bob/",
    "name": "Bob",
    "kernel_opts": ""
}