deck file patch

The deck file patch command allows you to add, update, or remove values from a declarative configuration file. A patch is a combination of a selector that selects which objects to patch in the file, and a value that contains the new value to use.

The data type of the property identified by selector defines the merge behavior. For scalar values (strings, integers, booleans) the existing value is overwritten. For arrays, the provided values are appended to the existing array if the selector is an array.

Changes can be specified as command line arguments, or provided in a patch file that is passed to the deck file patch command.

The deck file patch command outputs the patched file to stdout by default. You can provide -o /path/to/config.yaml to write the updated configuration to a file on disk.

Command line arguments

To patch values using the command line, pass the --selector and --value arguments.

You can run the following examples as deck file patch -s /path/to/kong.yaml --selector <S> --value <V>.

# set field "read_timeout" to a numeric value of 10000
--selector="$..services[*]" --value="read_timeout:10000"

# set field "_comment" to a string value
--selector="$..services[*]" --value='_comment:"comment injected by patching"'

# set field "_ignore" to an array of strings
--selector="$..services[*]" --value='_ignore:["ignore1","ignore2"]'

# remove fields "_ignore" and "_comment" from the object
--selector="$..services[*]" --value='_ignore:' --value='_comment:'

# append entries to the methods array of all route objects
--selector="$..routes[*].methods" --value='["OPTIONS"]'

Patch file

If you have more complex patching needs, you can store the patches in a YAML file. The YAML file contains selectors and values, plus an explicit remove key for deleting values.

patches:
  - selectors:
      - $..services[*]
    values:
      read_timeout: 10000
      _comment: comment injected by patching
    remove:
      - _ignore
      - _comment

To apply the above file, run deck file patch -s /path/to/config.yaml patch1.yaml patch2.yaml. Multiple patch files can be provided at once.