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Instance Tags

Introduction to Instance Tags

Instance tags in OpenStack are string values that you can associate with instances (virtual machines) to help manage and organise them. These tags are useful for categorising instances based on various criteria like environment, project, owner, or purpose. Tags make it easier to filter and search for instances, apply bulk actions, and manage resources efficiently. By effectively using instance tags in OpenStack, you can significantly enhance the manageability and automation capabilities of your cloud environment. Tags provide a flexible and powerful way to organise, query, and manage your instances, making your cloud operations more efficient and streamlined.

Benefits of Using Instance Tags:

  • Organization: Group instances by common attributes.
  • Searchability: Easily find and filter instances.
  • Automation: Use tags to trigger automation scripts and policies.
  • Reporting: Generate reports based on tagged instances.

Example Use Cases:

  • Environment Identification: Tag instances as "development", "staging", or "production".
  • Project Allocation: Assign tags to instances based on different projects.
  • Ownership Tracking: Track instances by tagging them with owner information.

Associate Tags with an Instance

Instance tags are string values. You can set and unset these tags using the OpenStack CLI.

Set Instance Tags

To set a tag use: 

openstack --os-compute-api-version 2.26 server set --tag development <instance_id>

To unset a tag use: 

openstack --os-compute-api-version 2.26 server unset --tag development <instance_id>

For some openstack CLI commands there is a need to specify API version, like here --os-compute-api-version parameter with the value 2.26.

In this example:

  • development tags the instance as part of the development environment.
  • <instance_id> is the unique identifier of the instance you are tagging.

Show Instance Tags

openstack server show <instance_id> -c tags
Example output 
Show instance tags output
+-------+-------------+
| Field | Value       |
+-------+-------------+
| tags  | development |
+-------+-------------+

Query and Use Instance Tags

Once you have tagged your instances, you can query and use these tags to manage your instances more effectively.

List instances that match specific tag value with detailed information.

openstack server list --tags development
This command lists all instances tagged with development.

Tags can also be used to generate reports. For instance, you can create a report of all instances belonging to a specific project.

openstack server list --long --tags project-alpha -f json > alpha_project_instances.json

This command exports a JSON report of all instances tagged with project-alpha.