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 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
transforms a string into its lowercase 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 the first character of a string.
$ docker inspect --format "{{title .Name}}" container
upper
upper
transforms a string into its uppercase representation.
$ docker inspect --format "{{upper .Name}}" container