Create
To add a data bag in the Chef Infra Server, we use the create argument.
Syntax
The syntax for the create argument is as follows:
knife data bag create DATA_BAG_NAME [DATA_BAG_ITEM] (options)
Options
The argument has the following options:
DATA_BAG_ITEM
-
This defines the name of the specific item in the data bag. The name of the data bag item cannot be client, node, role or environment because these are the reserved keywords for the knife search.
--secret SECRET
-
The encryption key that is used for the values contained within the data bag item. If the secret is not given, Chef Infra Client looks for a secret at the path specified by the encrypted_data_bag_secret setting in the client.rb file. For encrypted data bag items, use either --secret-file or--secret, not both.
--secret-file FILE
- This is the path of the file. It contains the encryption key.
Examples
The following example illustrates the knife subcommand.
Creating a data bag
knife data bag create admins
To return
Created data_bag[admins]
Delete
The delete argument in the knife is used to delete a data bag or a data bag item from the Chef Infra Server.
Syntax
The syntax for the delete argument is as follows:
knife data bag delete DATA_BAG_NAME [DATA_BAG_ITEM] (options)
Options
The argument has the following options:
DATA_BAG_ITEM
- This defines the name of the specific item in the data bag.
Example
The following example illustrates the knife subcommand.
Deleting a data bag
knife data bag delete data_bag_name
Deleting a data bag item
To delete an item named “soham”, enter the following:
knife data bag delete admins soham
Finally, enter ‘Y’ to confirm a delete operation.
Edit
The edit argument in the knife is used to edit the data that is present in the data bag. If encryption is being used, the data bag will be decrypted. Before being saved to the Chef Infra Server, the data will first be made available in the $EDITOR and then encrypted once again.
Syntax
The syntax for the delete argument is as follows:
knife data bag edit DATA_BAG_NAME [DATA_BAG_ITEM] (options)
Options
The argument has the following options:
DATA_BAG_ITEM
-
This defines the name of the specific item in the data bag. The name of the data bag item cannot be client, node, role or environment because these are the reserved keywords for the knife search.
--secret SECRET
-
The encryption key that is used for the values contained within the data bag item. If the secret is not given, Chef Infra Client looks for a secret at the path specified by the encrypted_data_bag_secret setting in the client.rb file. For encrypted data bag items, use either --secret-file or--secret, not both.
--secret-file FILE
- This is the path of the file. It contains the encryption key.
Example
The following example illustrates the knife subcommand.
Editing a data bag
knife data bag edit codingninjas soham
Here, codingninjas is the name of the data bag, and soham is the item name inside the data bag. This will return the following thing in the knife editor:
{
"name":"data_bag_item_codingninjas_soham",
"json_class":"Chef::DataBagItem",
"chef_type":"data_bag_item",
"data_bag":"codingninjas",
"raw_data":
{
"description":"soham is a technical blog writer",
"id":"soham"
}
}
Change the key-value pairs under raw data as appropriate, then save the changes.
From File
You can use the from file argument for the following operations:
- Updating the contents of the data bag item present inside the data bag.
- Adding the item to the data bag.
The data bag itself must be specified as part of the operation and must be available on the Chef Infra Server. A JSON file is used to specify the content of the data bag item. This JSON file's location must be supplied as part of the command; it can be either a relative or an absolute path. The JSON file that defines the contents of the data bag item must at least contain the name of the data bag item—"id": "name".
Syntax
The syntax for the from file argument is as follows:
knife data bag from file DATA_BAG_NAME_or_PATH JSON_FILE
Options
The argument has the following options:
-a, --all
-
Uploads all the data bags found at the given path.
--secret SECRET
-
The encryption key that is used for the values contained within the data bag item. If the secret is not given, Chef Infra Client looks for a secret at the path specified by the encrypted_data_bag_secret setting in the client.rb file. For encrypted data bag items, use either --secret-file or--secret, not both.
--secret-file FILE
- This is the path of the file. It contains the encryption key.
Example
The following example illustrates the knife subcommand.
Creating a data bag from a file
The following example will create a data bag from a file. The data bag will be created on the Chef Infra Server.
knife data bag from file "path of the JSON file"
Create an encrypted data bag from a file
The following example will create a data bag having the name “coding_ninjas”. The data bag will contain encrypted data.
knife data bag from file coding_ninjas --secret-file "path of the decryption file"
List
The list argument in the knife is used to display a list of data bags. It will display all the data bags that are available on the Chef Infra Server.
Syntax
The syntax for the list argument is as follows:
knife data bag list
Options
The argument has the following options:
-w, --with-uri
- The corresponding URIs are displayed.
Examples
The following example illustrates the knife subcommand.
Viewing a list of data bags
knife data bag list
Show
The show argument in the knife is used to view the contents of the data bag.
Syntax
The syntax for the show argument is as follows:
knife data bag show DATA_BAG_NAME (options)
Options
The argument has the following options:
DATA_BAG_ITEM
-
This defines the name of the specific item in the data bag.
--secret SECRET
-
The secret is the encryption key that protects values in a data bag item. Chef Infra Client searches for a secret at the location indicated by the encrypted_data_bag_secret argument in the client.rb file if the secret is not specified.
--secret-file FILE
- This is the path of the file. It contains the encryption key.
Examples
The following example illustrates the knife subcommand.
Displaying a data bag
knife data bag show admins
The output of the above command is displayed below.
soham
Showing a data bag item
To display the contents of a specific item within the data bag:
knife data bag show admins soham
The output of the above command
comment: Coder Soham
gid: ops
id: soham
shell: /bin/zsh
uid: 1005
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 the difference between Chef and Ansible?
Chef is a for-profit automation tool, whereas Ansible is an open-source IT automation solution. Ansible is used for application deployment automation and configuration management. Used for short procedures like updating the RHEL or Linux operating systems.
Is Chef a programming language?
Chef is an esoteric programming language. Programs in Chef look like recipes. The main principle of language design is: that program recipes should not only generate valid output but be easy to prepare and delicious.
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 have discussed the data bag of Knife. We have also learned some basic commands of the knife data bag. 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.
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