Knife Download
knife download subcommand in Chef’s command line tool is used to download cookbooks, nodes, roles, data bags, and environments from the Chef Infra Server to the working directory. It can be used to retrieve out-of-process modifications users may have made to documents on the Chef Infra Server, such as if a user performed a modification that bypassed version source control. It can also be used to back up data on the Chef Infra Server and examine the status of one or more files or analyze the state of many files.
Syntax
The syntax of the knife download subcommand is given below:
knife download [pattern . . .] (options)
Options
Following are the options of the knife download subcommand:
--chef-repo-path PATH
- This option defines the path to the chef-repo. With this setting, the default path will be overridden to the chef-repo. The default value of this option is equal to the value specified by chef_repo_path in the client.rb file.
--concurrency
- This option defines the number of concurrent connections allowed. The default value of this option is set to 10.
--repo-mode MODE
- This option defines the layout of the local chef-repo. The possible values of this option are static, hosted_everything, or everything. The value static is used for roles, cookbooks, data bags, and environments. The default value of this option is set to everything and hosted_everything dynamically. The value of this option depends on the type of server.
--cookbook-version VERSION
- This denotes the version of the cookbook to download.
-n, --dry-run
- This option takes no action. It only prints out the results. The default value of this option is set to false.
--[no-]force
- The --force option is used to download the files even if the file on your hard drive and the server object are identical. The default value of this option is set to --no-force.
--[no-]purge
- The --purge option is used to delete directories and local files that are not present on the Chef Infra Server. The default value of this option is set to --no-purge.
--[no-]rescue
- The --no-rescue option is used to disable the recursive downloading of a directory. The default value of the option is set to --recurse.
Examples
The following example illustrates the knife subcommand.
Downloading an entire chef-repo
Navigate to the top level of the chef-repo and enter the following command to download the whole chef-repo from the server.
knife download /
Downloading the /cookbooks directory
Navigate to the top level of the chef-repo and enter the following command to download the cookbooks/ from the server.
knife download cookbooks
Knife Edit
knife edit subcommand in Chef’s command line tool is used to edit objects on the Chef Infra Server. The functioning of this subcommand is similar to knife data bag edit, knife cookbook edit, knife node edit, knife role edit, and knife environment edit but with a single verb (and a single action).
Syntax
The syntax of the knife edit subcommand is given below:
knife edit (options)
Options
Following are the options of the knife edit subcommand:
--chef-repo-path PATH
- This option defines the path to the chef-repo. With this setting, the default path will be overridden to the chef-repo. The default value of this option is equal to the value specified by chef_repo_path in the client.rb file.
--concurrency
- This option defines the number of concurrent connections allowed. The default value of this option is set to 10.
--repo-mode MODE
- This option defines the layout of the local chef-repo. The possible values of this option are static, hosted_everything, or everything. The value static is used for roles, cookbooks, data bags, and environments. The default value of this option is set to everything and hosted_everything dynamically. The value of this option depends on the type of server.
--local
- This option shows files in the local chef-repo . The default value of this option is set to false.
Example
The following example illustrates the knife subcommand.
Removing a user from /groups/admin.json
If a user is belonging to admin group. Then the user must be removed from the admin group before it is removed from an organization.
EDITOR=vi knife edit /groups/admin.json
After making the necessary changes save the file.
Knife Deps
knife deps subcommand in Chef’s command line tool is used to identify dependencies for a role, cookbook, or node.
Syntax
The syntax of the knife deps subcommand is given below:
knife deps (options)
Options
Following are the options of the knife deps subcommand:
--chef-repo-path PATH
- This option defines the path to the chef-repo. With this setting, the default path will be overridden to the chef-repo. The default value of this option is equal to the value specified by chef_repo_path in the client.rb file.
--concurrency
- This option defines the number of concurrent connections allowed. The default value of this option is set to 10.
--repo-mode MODE
- This option defines the layout of the local chef-repo. The possible values of this option are static, hosted_everything, or everything. The value static is used for roles, cookbooks, data bags, and environments. The default value of this option is set to everything and hosted_everything dynamically. The value of this option depends on the type of server.
--[no-]rescue
- The --no-rescue option is used to disable the recursive listing of dependencies. The default value of the option is set to --recurse.
--remote
- This option helps us to determine the dependencies from the objects that are located on the Chef Infra Server. The default value of this option is set to false.
--tree
- This option helps us to display the dependencies in a tree structure. The default value of this option is set to false.
Example
The following example illustrates the knife subcommand.
Finding dependencies for a node.
knife deps nodes/name_of_node.json
Finding dependencies for a role.
knife deps roles/name_of_role.json
Knife Diff
knife diff subcommand in Chef’s command line tool is used to compare the differences between directories and files in the chef-repo and on the Chef Infra Server. For instance, to check that particular files are the same across several production environments before utilizing the knife download and knife upload subcommands to upload or download files from the Chef Infra Server.
Syntax
The syntax of the knife diff subcommand is given below:
knife diff [PATTERN...] (options)
Options
Following are the options of the knife diff subcommand:
--chef-repo-path PATH
- This option defines the path to the chef-repo. With this setting, the default path will be overridden to the chef-repo. The default value of this option is equal to the value specified by chef_repo_path in the client.rb file.
--concurrency
- This option defines the number of concurrent connections allowed. The default value of this option is set to 10.
--repo-mode MODE
- This option defines the layout of the local chef-repo. The possible values of this option are static, hosted_everything, or everything. The value static is used for roles, cookbooks, data bags, and environments. The default value of this option is set to everything and hosted_everything dynamically. The value of this option depends on the type of server.
--cookbook-version VERSION
- This denotes the version of the cookbook to download.
--[no-]rescue
- The --no-rescue option is used to disable the recursive listing of dependencies. The default value of the option is set to --recurse.
--name-only
- This will display the names of the modified files.
--name-status
- This will display the names of the files with the status of Delete, Added, Type Changed, or Modified.
Example
The following example illustrates the knife subcommand.
Comparing files containing JSON data.
The following command will compare the thewebserver.json and thebase.json file.
knife diff roles/thewebserver.json roles/thebase.json
Comparing the server and the chef-repo
knife diff
Frequently Asked Questions
What is the Chef automation tool?
A chef is an automation tool. It provides a way to define infrastructure as code. It means managing infrastructure by writing code. It is also called a programmable infrastructure.
How much does Chef automation cost?
Chef automate costs $137 per annum per node. It includes everything that is necessary for building and deploying software.
What is Chef knife used for?
A system administrator's tool that communicates with the server to load cookbooks and customised configuration. With this component, it is also feasible to boot some servers from scratch.
Is Chef a programming language?
Chef is an esoteric programming language. Programs in Chef look like recipes. The main principle of language design is: program recipes should be easy to prepare and delicious and not just to generate valid output.
What is Chef in DevOps?
A Chef is an automation tool used in DevOps. It is a Configuration Management (CM) application that enables you to easily automate procedures across several servers and other devices of a business.
Conclusion
In this article, we discussed the features of Chef Knife. We learn about knife delete, knife download, knife edit, knife deps, and knife diff subcommands. To learn more about Knife, check out our articles on
Refer to our guided paths on Coding Ninjas Studio to learn more about DSA, Competitive Programming, JavaScript, System Design, etc. Enroll in our courses and attempt the mock test and problems given on our platform. Take a look at the interview experiences and interview bundle for placement preparations.
Happy Learning, Ninjas!
34+ registered 
