Introduction To Configuration Management Using CHEF

In today’s microservices-and-continuous-integration driven world, where apps run in hybrid cloud environments and users engage with them on any device and on any underlying operating system, applications are increasingly complex.

With so much on the line, it’s more important than ever for organizations to do everything within their power to make sure their systems are operable and available around the clock and around the world.

For example, you want to deploy or update an application, an operating system, or software on multiple systems in one day. There is no restriction on using manual processes, although the possibility of multiple errors still exists. Other possible issues may include the crashing of software during updates without any chance of reverting back to the previous version. In such cases, configuration management works effectively.

Configuration management tools such as Chef can carry out the work of many system admins and developers with ease and effectiveness.

Why Use Chef?

1. Chef uses a pull mechanism in which the nodes are dynamically updated with the configurations that are present in the server.
2. Chef can easily manage a large number of servers with fewer employees.
3. It allows continuity in the deployment process from building to testing, until the end.
4. It can be managed using different Operating Systems like Linux, FreeBSD, and Windows.
5. It can be integrated with several major cloud service providers like Azure, AWS, GCP, etc.
6. A single chef-server may be used as a center for all policy deployment.
7. Chef is a reliable and stable tool for large deployments.
8. It also helps in managing the risk at all stages of deployment.

Some Terms related to CHEF :

1. Node: The machine in which recipes and roles are applied during the Chef client run.
2. Recipe: The fundamental part of Chef, it is a collection of resources that are executed in the order to configure a node.
3. Cookbook: Contain all resources and instructions that you need to configure your nodes. These can be reused across different run lists. Cookbooks typically consist of many recipes.
4. Data Bag: Contain globally available data used by nodes and roles.
5. Resource: Users, packages, files, or directories.
6. Attributes: Represent node settings, for example, hostname, versions of programming languages to install, database server, etc.
7. Chef-Client: Does all work on behalf of a node, where it executes recipes to configure and install the software.
8. Chef Solo: A command-line tool that allows you to run Chef cookbooks without an actual Chef server. It is an open-source version of the Chef client.
9. Knife: A tool used by engineers to upload configuration changes to the Chef server.
10. Ohai: A tool for collecting data about your operating system, used to provide system attributes used by Chef client during Chef run.
11. Role: A way to group similar features of nodes, for easier management.

Chef Architecture

The Chef architecture consists of three core components that interact with one another: Chef server, actual servers called nodes and Chef workstation.

Chef-Architecture

Chef-Workstation

A workstation on Chef is the computer that runs Chef Workstation. The Chef Workstation helps in authoring cookbooks, interactive with nodes, and the Chef Infra Server. The workstations help users in addressing the following tasks,

• Development and testing of cookbooks and recipes.
• Testing the Chef code.
• Maintaining synchronization of the Chef repository with version source control.
• Interaction with nodes according to requirements such as conducting a bootstrap operation when required.
• Configuration of organizational policy alongside the definition of roles and environments and ensuring the storage of critical data in data bags.

Chef Workstation provides the benefits of easy installation, along with a diverse range of features. Chef Workstation provides ad-hoc remote execution, cookbook creation tools, reliable dependency, and testing software, remote scanning, and configuration tasks.

Chef-Server

The Chef server stores ,manage, and provides configuration data to all other Chef components.

From Chef-Workstation, one can push all the cookbooks and any new node can communicate with the Chef-server and the chef-client installed on the node will help to run all the cookbooks and roles to install and configure the required packages.

Wrapping Up :

By using configuration management tools like Chef to manage your infrastructure you can take the best practices from application development and apply them to the development and scaling of your server infrastructure.

The stability, maturity, and reliability of Chef for large-scale deployments in public and private environments are promising features that Chef provides.