knife xargs

The knife xargs subcommand is used to take patterns from standard input, download as JSON, run a command against the downloaded JSON, and then upload any changes.

Syntax

This subcommand has the following syntax:

$ knife xargs [PATTERN...] (options)

Options

Note

Review the list of common options available to this (and all) knife subcommands and plugins.

This subcommand has the following options:

-0

Use to show a NULL character (\0) instead of white space as the separator. Default: false.

--chef-repo-path PATH

The path to the chef-repo. This setting will override the default path to the chef-repo. Default: same value as specified by chef_repo_path in client.rb.

--concurrency

The number of allowed concurrent connections. Default: 10.

--[no-]diff

Use to show a diff when a file changes. Default: --diff.

--dry-run

Use to prevent changes from being uploaded to the Chef server. Default: false.

--[no-]force

Use to force the upload of files even if they haven’t been changed. Default: --no-force.

-I REPLACE_STRING, --replace REPLACE_STRING

Use to define a string that will be used to replace all occurrences of a file name. Default: nil.

-J REPLACE_STRING, --replace-first REPLACE_STRING

Use to define a string that will be used to replace the first occurrence of a file name. Default: nil.

--local

Use to build or execute a command line against a local file. Set to false to build or execute against a remote file. Default: false.

-n MAX_ARGS, --max-args MAX_ARGS

The maximum number of arguments per command line. Default: nil.

-p [PATTERN...], --pattern [PATTERN...]

One (or more) patterns for a command line. If this option is not specified, a list of patterns may be expected on standard input. Default: nil.

--repo-mode MODE

The layout of the local chef-repo. Possible values: static, everything, or hosted_everything. Use static for just roles, environments, cookbooks, and data bags. By default, everything and hosted_everything are dynamically selected depending on the server type. Default value: default.

-s LENGTH, --max-chars LENGTH

The maximum size (in characters) for a command line. Default: nil.

-t

Use to run the print command on the command line. Default: nil.

Examples

The following examples show how to use this knife subcommand:

Use output of knife deps to pass command to knife xargs

The following examples show various ways of listing all nodes on the server, and then using Perl to replace grantmc with gmc:

$ knife list 'nodes/*' | knife xargs "perl -i -pe 's/grantmc/gmc'"

or without quotes and the backslash escaped:

$ knife list /nodes/\* | knife xargs "perl -i -pe 's/grantmc/gmc'"

or by using the --pattern option:

$ knife xargs --pattern '/nodes.*' "perl -i -pe 's/grantmc/gmc'"