Annotating machine details

The power of annotations in MAAS

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Annotations in MAAS are potent tools for adding context and metadata to your machines. They act as supplementary data that allow you to identify, filter, and manage your machines more effectively. Essentially, annotations fall into two categories:

1. Notes: These are always available, regardless of the machine's state.
2. Dynamic Annotations: These only exist when a machine is in an allocated or deployed state.

Note: Dynamic annotations aren't supported in MAAS version 2.9 or earlier.

Mastering the art of notes

Notes are persistent descriptions that stay with a machine throughout its lifecycle unless manually altered. You can manage notes through both the MAAS UI and CLI.

Navigating notes in the MAAS UI

To add or modify notes via the MAAS UI:

1. Navigate to Machines > Machine name > Configuration > Edit.
2. Your existing notes appear in the Note section.
3. Add new or modify existing notes in the Note section.
4. Delete irrelevant notes from the same block.
5. Make sure to Save changes to confirm your actions.

Navigating notes via CLI

Identifying your machines

To determine machine identifiers, run the following command:

maas $PROFILE machines read \
| jq -r '(["hostname","system_id"]
|(.,map(length*"-"))),(.[]|[.hostname,.system_id])
|@tsv' | column -t

Managing notes in CLI

You can add or modify a note as follows:

maas $PROFILE machine update $SYSTEM_ID description="$NOTE"

To erase a note, just use an empty string:

maas $PROFILE machine update $SYSTEM_ID description=""

The road to dynamic annotations

Dynamic annotations are ephemeral data, tied to the operational states of allocated or deployed machines. These annotations are especially handy for tracking the live status of your workloads.

Identifying eligible machines for dynamic annotations

To list machines that can receive dynamic annotations, execute:

maas $PROFILE machines read \
| jq -r '(["hostname","system_id","status"]
|(.,map(length*"-"))),(.[]|[.hostname,.system_id,.status_name])
|@tsv' | column -t

Setting dynamic annotations

You can define dynamic annotations using key=value pairs. To set one, use:

maas $PROFILE machine set-owner-data $SYSTEM_ID $KEY=$VALUE

Managing dynamic annotations

To change or remove a dynamic annotation, use the following commands:

• For changing:

maas $PROFILE machine set-owner-data $SYSTEM_ID $KEY=$NEW_VALUE

• For removing:

maas $PROFILE machine set-owner-data $SYSTEM_ID $KEY=""

Listing dynamic annotations

To view all current dynamic annotations, run:

maas $PROFILE machines read \
| jq -r '(["hostname","system_id","owner_data"]
|(.,map(length*"-"))),(.[]|[.hostname,.system_id,.owner_data[]])
|@tsv' | column -t

Summary

Annotations in MAAS offer an additional layer of intelligence to your machine management. While notes provide a stable form of annotations, dynamic annotations offer a more fluid form of tracking, directly linked to your machine's operational status. Both these tools, combined with the power of the MAAS UI and CLI, give you complete control over your machine metadata.