Apply custom metadata (Engine)

Docker object labels

Labels are a mechanism for applying metadata to Docker objects, including:

• Images
• Containers
• Local daemons
• Volumes
• Networks
• Swarm nodes
• Swarm services

You can use labels to organize your images, record licensing information, annotate relationships between containers, volumes, and networks, or in any way that makes sense for your business or application.

Label keys and values

A label is a key-value pair, stored as a string. You can specify multiple labels for an object, but each key-value pair must be unique within an object. If the same key is given multiple values, the most-recently-written value overwrites all previous values.

Key format recommendations

A label key is the left-hand side of the key-value pair. Keys are alphanumeric strings which may contain p