Working with labels and selectors

Labels are 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
• Set-based:
  • Use in or notin operators

Getting ready

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...