Chapter 5. Additional resources
5.1. Tag specifications by integration type
Tagging standards differ between integration types. To use the same tags/labels across integrations, 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:
| Criteria | AWS | Azure | Google Cloud | Red Hat OpenShift |
|---|---|---|---|---|
| Name | Tags | Tags | Labels | Labels |
| Format | Key & value | Name & value | Key & value | Key & value Keys: [prefix/]name Prefix: must be a DNS subdomain |
| Allows empty value | Yes | Yes | Yes | Yes |
| Unique label per key | Yes | Yes | Yes | Yes |
| Case sensitive | Yes | No | Only lowercase letters | Yes |
| Limit per resource | 50 | 50 (15 for storage) | 64 | N/A |
| Length of key | 128 | 512 (128 for storage) | 63 | 253(prefix) / 63(name) |
| Length of value | 256 | 256 | 63 | 63 |
| Allowed characters | Letters, numbers, and spaces representable in UTF-8, and the following characters: + - = . _ : / @ | Tag names cannot contain these characters: <, >, %, &, \, ?, / | Only lowercase letters, numeric characters, underscores, and dashes. | 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. | Keys must start with a lowercase letter or international character. | 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. | There is no limit on how many labels you can apply across all resources within a project. | 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 integration type.
AWS:
OpenShift:
Microsoft Azure:
Google Cloud:
