Labelsare a set of key/value pairs, which are attached to object metadata. We could use labels to select, organize, and group objects, such as Pods, ReplicaSets, and Services. Labels are not necessarily unique. Objects could carry the same set of labels.
Label selectors are used to query objects with labels of the following types:
- Equality-based:
- Use equal (
=or==) or not-equal (!=) operators
- Use equal (
- Set-based:
- Use
inornotinoperators
- Use
Before you get to setting labels in the objects, you should consider the valid naming convention of key and value.
A valid key should follow these rules:
- A name with an optional prefix, separated by a slash.
- A prefix must be a DNS subdomain, separated by dots, no longer than 253 characters.
- A name must be less than 63 characters with the combination of [a-z0-9A-Z] and dashes, underscores, and dots. Note that symbols are illegal if put at the beginning and the end.
A valid value should follow the following rules:
- A name must be...