Format command and log output

Docker uses Go templates to allow users manipulate the output format of certain commands and log drivers. Each command a driver provides a detailed list of elements they support in their templates:

• Docker Images formatting
• Docker Inspect formatting
• Docker Log Tag formatting
• Docker Network Inspect formatting
• Docker PS formatting
• Docker Volume Inspect formatting
• Docker Version formatting

Template functions

Docker provides a set of basic functions to manipulate template elements. This is the complete list of the available functions with examples:

Join

Join concatenates a list of strings to create a single string. It puts a separator between each element in the list.

$ docker ps --format '{{join .Names " or "}}'

Json

Json encodes an element as a json string.

$ docker inspect --format '{{json .Mounts}}' container

Lower

Lower turns a string into its lower case representation.

$ docker inspect --format "{{lower .Name}}" container

Split

Split slices a string into a list of strings separated by a separator.

$ docker inspect --format '{{split (join .Names "/") "/"}}' container

Title

Title capitalizes a string.

$ docker inspect --format "{{title .Name}}" container

Upper

Upper turns a string into its upper case representation.

$ docker inspect --format "{{upper .Name}}" container