Tags for different objects have similar purposes, but they aren't necessarily administered in the same way -- so we've included detailed articles for each tag type. That said, many of the common operations regarding tags are performed in the same way. This article will present some general, explanatory information, and then look at tag management steps that are the same (or very similar) across all types of MAAS tags.
When working with tags, there are some universal rules you need to follow:
In general, names that do not conform to these rules cannot be created.
How to download hardware configuration information
To download hardware configuration information in XML format:
Select Machines.
Select a machine which is allocated or deployed.
Select Logs >> Installation output >> Download >> Machine output (XML).
You can learn more about these attributes↗ if desired. Note that:
You can also find device classes from the same sources.
MAAS 3.2 and above provide greatly expanded tagging capability. You can auto-apply tags to machines that match a custom XPath expression. Setting up an automatic tag lets you recognise special hardware characteristics and settings, e.g., the gpu passthrough.
Automatic tags are only available via the MAAS UI.
How to update the kernel options on a tag
To update the kernel options on a tag:
Select Machines.
Select Tags.
Select the pencil icon on the right end of the tag's row.
Edit the Kernel options.
Select Save to register your changes.
Kernel options can exist for both manual and automatic tags. However, they will be applied during boot time (commissioning and deploying).
[note] If the tagged machines are deployed, the updated kernel option won’t apply until the machines are redeployed. We suggest that you release those machines prior to the update, then redeploy those machines when the kernel options of the tag are updated. [/note]
How to unassign tags from machines
To unassign tags from machines:
Select Machines.
Select the checkbox(es) next to the machine(s) you wish to untag.
Select Take action >> Tag. A table of tags appears at the top of the screen.
For each tag you wish to unassign, select Remove. The text will change to Discard with an X to the right.
If you want to undo a choice before saving, click the X to right of Discard to undo the proposed change.
When you're satisfied with your new tag configuration, select Save to finalize and register your choice(s).
[note] Automatic tags cannot be unassigned manually. You can either update or delete automatic tags. [/note]
You can also unassign tags individually by going to Machines >> {machine-name} >> Configuration >> Tags >> Edit. The Tags table functions exactly the same as what's described above.
To see how many nodes (Machines, controllers, devices) are tagged, search for GRUB_CMDLINE_LINUX_DEFAULT in the "Installation output" tab of the machine details page. That log should stay around for the lifetime of the deployment of the machine. The log gets overwritten when you redeploy the machine. For example:
GRUB_CMDLINE_LINUX_DEFAULT="sysrq_always_enabled dyndbg='file drivers/usb/* +p' console=tty1 console=ttyS0"
With the CLI, you can create a tag with the following command:
maas $PROFILE tags create name=$TAG_NAME comment='$TAG_COMMENT'
For example, depending upon your system configuration, you might type a command similar to this one:
maas admin tags create name="new_tag" comment="a new tag for test purposes"
When the command is successful, you should see output similar to this:
Success.
Machine-readable output follows:
{
"name": "new_tag",
"definition": ",
"comment": "a new tag for test purposes",
"kernel_opts": ",
"resource_uri": "/MAAS/api/2.0/tags/new_tag/"
}
You can verify your work by listing all the tags on this MAAS.
How to create tags with built-in kernel options
You can create tags with embedded kernel boot options. When you apply such tags to a machine, those kernel boot options will be applied to that machine on the next deployment.
To create a tag with embedded kernel boot options, use the following command:
maas $PROFILE tags create name='$TAG_NAME' \
comment='$TAG_COMMENT' kernel_opts='$KERNEL_OPTIONS'
For example:
maas admin tags create name='nomodeset_tag' \
comment='nomodeset_kernel_option' kernel_opts='nomodeset vga'
This command yields the following results:
Success.
Machine-readable output follows:
{
"name": "nomodeset_tag",
"definition": ",
"comment": "nomodeset_kernel_option",
"kernel_opts": "nomodeset vga",
"resource_uri": "/MAAS/api/2.0/tags/nomodeset_tag/"
}
You can check your work with a modified form of the listing command:
maas admin tags read | jq -r \
'(["tag_name","tag_comment","kernel_options"]
|(.,map(length*"-"))),(.[]|[.name,.comment,.kernel_opts])
| @tsv' | column -t
This should give you results something like this:
tag_name tag_comment kernel_options
-------- ----------- --------------
virtual
new_tag a-new-tag-for-test-purposes
pod-console-logging console=tty1 console=ttyS0
nomodeset_tag nomodeset_kernel_option nomodeset vga
With the CLI, you can delete a tag with the following command:
maas $PROFILE tag delete $TAG_NAME
For example, depending upon your system configuration, you might type a command similar to this one:
maas admin tag delete zorko
When the command is successful, you should see output similar to this:
Success.
Machine-readable output follows:
Note that there is no actual "Machine-readable output" produced by this command, in most cases. Also note that remove a tag removes it from any nodes where you may have assigned it, but does not affect those nodes in any other way.
You can check your work by listing all the tags on this MAAS.
You can update a tag (e.g., a tag comment) like this:
maas $PROFILE tag update $TAG_NAME comment='$TAG_COMMENT'
For example:
maas admin tag update new_tag comment="a-new-tag-for-test-purposes"
This should return an output similar to this one:
Success.
Machine-readable output follows:
{
"name": "new_tag",
"definition": ",
"comment": "a-new-tag-for-test-purposes",
"kernel_opts": ",
"resource_uri": "/MAAS/api/2.0/tags/new_tag/"
}
You can always verify by listing all the tags on this MAAS.
How to list all tags available on this MAAS
You can list all tags that currently exist in this MAAS with a command of the form:
maas $PROFILE tags read | jq -r '(["tag_name","tag_comment"]|(.,map(length*"-"))),(.[]|[.name,.comment]) | @tsv' | column -t
For example:
maas admin tags read | jq -r '(["tag_name","tag_comment"]|(.,map(length*"-"))),(.[]|[.name,.comment]) | @tsv' | column -t
Your output might look like this:
tag_name tag_comment
-------- -----------
virtual
new_tag a-new-tag-for-test-purposes
If you need to update tags for all machines – without having to recommission them – you can accomplish this with the rebuild command:
maas $PROFILE tag rebuild $TAG
This command automatically applies the tag to all machines regardless of state, even machines that are actively deployed. For example:
maas admin tag rebuild virtual
This command would produce output similar to the following:
Success.
Machine-readable output follows:
{
"rebuilding": "virtual"
}