Chapter 5. Additional resources

5.1. Tag specifications by source type

Tagging standards differ between source types. To use the same tags/labels across sources, you must use the most common of all the restrictions across the different providers.

The following table summarizes tagging and labelling criteria across AWS, Azure and OpenShift Container Platform 4:

Table 5.1. Tagging specifications by source

CriteriaAWSAzureRed Hat OpenShift

Name

Tags

Tags

Labels

Format

Key & value

Name & value

Key & value Keys: [prefix/]name Prefix: must be a DNS subdomain

Allows empty value

Yes

Yes

Yes

Unique label per key

Yes

Yes

Yes

Case sensitive

Yes

No

Yes

Limit per resource

50

50 (15 for storage)

N/A

Length of key

128

512 (128 for storage)

253(prefix) / 63(name)

Length of value

256

256

63

Allowed characters

Letters, numbers, and spaces representable in UTF-8, and the following characters: + - = . _ : / @

Tag names cannot contain these characters: <, >, %, &, \, ?, /

The name segment is required and must be 63 characters or less, beginning and ending with an alphanumeric character ([a-z0-9A-Z]) with dashes (-), underscores (_), dots (.), and alphanumerics between

Restrictions

The prefix “aws:” is reserved. Tags applied to EC2 can use any character. Not all resource types support tags.

Not all resource types support tags. Generalized VMs do not support tags. Tags applied to the resource group are not inherited by the resources.

Prefixes kubernetes.io/ and k8s.io/ are reserved. Not all resource types support tags.

Notes

You need to select the tag keys that will be included in cost and usage files and billing reports.

You can use a JSON string to go over the limit of keys.

If the prefix is omitted, the label Key is presumed to be private to the user.

5.2. Further reading

The following links provide further guidance on tagging for each source type.

AWS:

OpenShift:

Microsoft Azure: