The Different Flavors of Chef. Chef Wiki As A PDF .. As you learn to use Chef, you'll need to understand what each of the different. Learning Chef is like learning the basics of a language. • 80% fluency reached quickly. • 20% just takes practice. • The best way to LEARN Chef is to USE Chef. Chef is a configuration management technology developed by Opscode to We assume anyone who wants to learn Chef should have an understanding of.
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portal7.info Did you know that Packt offers eBook versions of every book published, with PDF These tools are very useful to learn and test Chef scripting. Learning Chef» A Guide To Configuration Management and Automation. If you' re new to Chef, this is the perfect book to get you started. Explore new avenues. Get a hands-on introduction to the Chef, the configuration management tool for solving operations issues in enterprises large and small. Ideal for developers and .
Get a hands-on introduction to the Chef, the configuration management tool for solving operations issues in enterprises large and small. Ideal for developers and sysadmins new to configuration management, this guide shows you to automate the packaging and delivery of applications in your infrastructure. After teaching you how to write Ruby-based Chef code, this book walks you through different Chef tools and configuration management concepts in each chapter, using detailed examples throughout. All you need to get started is command-line experience and familiarity with basic system administration. Stay ahead with the world's most comprehensive technology and business learning platform.
Ohai Ohai collects information regarding nodes for the Chef client.
It is required to be present on every node, and is installed as part of the bootstrap process. The information gathered includes network and memory usage, CPU data, kernel data, hostnames, FQDNs, and other automatic attributes that helps the Chef client determine the state of the node prior to applying that nodes run list. This allows for users to combine environments and versioned cookbooks to have different attributes for different nodes.
To change this, the environment should be defined in the client.
Cookbooks Cookbooks are the basis for managing the configurations on any node. Cookbooks contain values and information about the desired state of a node and then the Chef server and Chef client ensure that the defined state is achieved.
Cookbooks are comprised of recipes, metadata, attributes, resources, templates, libraries, and anything else that assists in creating a functioning system, with attributes and recipes being the two core parts of a cookbook. Components of a cookbook should be modular, keeping recipes small and related.
Cookbooks should be version controlled. Versions can help when using different Chef environments and allow you to distribute and collaborate on cookbooks with other team members.
Recipes A Chef cookbook is comprised of recipes that a nodes desired state. Recipes are written in Ruby and contain information about everything that needs to be run, changed, or created on a node.
Recipes work as a collection of resources that determine the configuration or policy of a node, with resources being a configuration element of the recipe. Attributes Attributes define specific values about a node and its configuration and are used by the Chef client to apply those attributes to nodes via its attribute list.
The chef client can receive attributes from nodes, attribute files, recipes, environments, and roles. Often attributes are used in conjunction with templates and recipes to define settings.
Files These are static files that can be uploaded to nodes. Files can be configuration and set-up files, scripts, website files. For example, you may have a recipe that uses an index. Libraries Although Chef comes with a number of libraries built in, additional libraries can be defined. Libraries allow you to write Ruby code to be included in a cookbook. Libraries are a convenient way to include helper code for your existing recipes.
Libraries provide a powerful way to extend the resources created by your recipes. Resources Resources are written in Ruby and defined in recipe files.
Resources must contain a type, a name, one or more properties, and one or more actions. Resources are the key components that make up any single recipe.
Templates Templates are embedded Ruby files. Predictability: DevOps offers significantly lower failure rate of new releases 2. Reproducibility: Version everything so that earlier version can be restored anytime. Maintainability: Effortless process of recovery in the event of a new release crashing or disabling the current system. This is particularly the case for digital and mobile applications. Greater Quality: DevOps helps the team to provide improved quality of application development as it incorporates infrastructure issues.
Reduced Risk: DevOps incorporates security aspects in the software delivery lifecycle. It helps in reduction of defects across the lifecycle.
Resiliency: The Operational state of the software system is more stable, secure, and changes are auditable. Cost Efficiency: DevOps offers cost efficiency in the software development process which is always an aspiration of IT companies' management.
Breaks larger code base into small pieces: DevOps is based on the agile programming method. Therefore, it allows breaking larger code bases into smaller and manageable chunks. When to adopt DevOps? DevOps should be used for large distributed applications such as eCommerce sites or applications hosted on a cloud platform.
When not to adopt DevOps? It should not be used in a mission-critical application like bank, power and other sensitive data sites. Such applications need strict access controls on the production environment, a detailed change management policy, access control policy to the data centers. DevOps Lifecycle DevOps is deep integration between development and operations. Understanding DevOps is not possible without knowing DevOps lifecycle.
Here is a brief information about the Continuous DevOps life-cycle: 1. Development In this DevOps stage the development of software takes place constantly. In this phase, the entire development process is separated into small development cycles. This benefits DevOps team to speed up software development and delivery process.
Testing QA team use tools like Selenium to identify and fix bugs in the new piece of code. Integration In this stage, new functionality is integrated with the prevailing code, and testing takes place. Continuous development is only possible due to continuous integration and testing.
Deployment In this phase, the deployment process takes place continuously. It is performed in such a manner that any changes made any time in the code, should not affect the functioning of high traffic website.
Monitoring In this phase, operation team will take care of the inappropriate system behavior or bugs which are found in production.
DevOps Work Flow Workflows provide a visual overview of the sequence in which input is provided. It also tells about actions are performed, and output is generated for an operations process. Workflow allows the ability to separate and arrange jobs which are top-requested by the users.
It also gives the ability to mirror their ideal process in the configuration jobs. Chef runs in a server client mode. Each node has a chef client software installed, which will pull down the configuration that are applicable to that node from the central chef server.
The central chef server has an optional web interface which provides several administrative capabilities to users managing chef. Nodes can be deleted and configurations applicable to a node can be modified using this central web interface. There are three different types of chef server available. Chef Solo : Actually chef solo is not a chef server. In fact it removes the need of having a central chef server to test configurations on nodes.
Open Source Chef: This is completely free and open source chef, which you can install anywhere. This makes you free from the responsibility of managing a central chef server yourself. Workstation Consider workstation as a system that can be used to control central chef server. As depicted in the above diagram, there can be multiple workstations that can together manage a central chef server. Workstations will do the below jobs. Writing cookbooks and recipes that will later be pushed to central chef server.
A cookbook is nothing but a unit that configures a particular thing on the node. Consider cookbooks as something that is designed to manage one specific component, service or application on the nodes. Let's take an example of installing and configuring MySQL database server on a node.
In that case you will have a cookbook for MySQL, that will take care of installing the required version, applying the required configuration parameters in mysql configuration files, adding users into mysql, creating required databases etc. In short, all aspects of a particular component that needs to be configured on the node can be placed inside a cookbook.
Managing Nodes on the central chef server.
The workstation system will have the required command line utilities, to control and manage every aspect of the central chef server. Things like adding a new node to the central chef server, deleting a node from the central chef server, modifying node configurations etc can all be managed from the workstation itself.
Basically workstation will have two main components. Knife utility: This command line tool can be used to communicate with the central chef server from workstation. Adding, removing, changing configurations, of nodes in central chef server will be carried out by using this knife utility.
Cookbooks can be uploaded to central chef server using knife utility, Roles and environments can be managed using knife utility. Basically every aspect of central chef server can be controlled from workstation using knife utility. A local Chef repository: This is the place where every configuration components of central chef server is stored.
This chef respository can be synchronized with the central chef server again using the knife utility itself.