In the world of software development, the term "as code" is a fundamental concept that forms the backbone of the DevOps philosophy. The phrase "as code" refers to the practice of managing and provisioning computing resources and environments through machine-readable definition files, rather than physical hardware configuration or interactive configuration tools. This approach is a cornerstone of the DevOps movement, which seeks to unify software development (Dev) and software operation (Ops).
The "as code" methodology is a key enabler of the automation and repeatability that are central to the DevOps approach. By treating infrastructure, security, and even the organization's culture "as code," teams can apply the same version control, testing, and continuous integration/continuous delivery (CI/CD) practices that they use for application code. This results in more reliable, efficient, and secure systems.
Definition of "As code"
The term "as code" is used to describe the practice of expressing infrastructure, security, and other aspects of IT in a format that can be version-controlled and automated. This is typically done using a high-level scripting or programming language that is both human-readable and machine-executable. The "as code" approach is a shift away from manual, interactive configuration and towards automation and repeatability.
The "as code" concept is not limited to infrastructure. It can also be applied to security (security as code), policy (policy as code), and even the organization's culture (culture as code). In each case, the goal is to express the desired state or behavior in a format that can be version-controlled, tested, and automated, just like application code.
Infrastructure as Code (IaC)
Infrastructure as Code (IaC) is the practice of managing and provisioning computer data centers through machine-readable definition files, rather than physical hardware configuration or interactive configuration tools. The IT infrastructure managed by this comprises both physical equipment such as bare-metal servers as well as virtual machines and associated configuration resources.
The definitions may be in a version control system. It can use either scripts or declarative definitions, rather than manual processes, but the term is more often used to promote declarative approaches. IaC approaches are promoted for cloud computing, which is sometimes marketed as Infrastructure as a Service (IaaS). IaC supports DevOps approaches.
Security as Code
Security as Code is the practice of writing security policies, procedures, and controls into the codebase and configuration files of an application. This allows for automated enforcement and monitoring of security controls, as well as version control and auditing of changes to these controls.
Security as Code is a key component of the DevSecOps movement, which seeks to integrate security practices into the DevOps workflow. By treating security "as code," teams can ensure that security is considered at every stage of the development lifecycle, rather than being an afterthought or a separate process.
History of "As code"
The concept of treating infrastructure as code has its roots in the early days of computing, when system administrators would write scripts to automate routine tasks. However, the term "Infrastructure as Code" was not coined until around 2006, with the advent of cloud computing and the recognition of the need for more efficient ways to manage large-scale, distributed systems.
The "as code" philosophy has since expanded beyond infrastructure to encompass other aspects of IT and organizational culture. The DevOps movement, which emerged around the same time as the "as code" concept, has been a major driver of this expansion. DevOps emphasizes collaboration, automation, and integration across all stages of the software development lifecycle, and the "as code" approach is a natural fit for this philosophy.
Evolution of "As code"
As the "as code" concept has evolved, it has been applied to more and more areas of IT and organizational culture. For example, the idea of "security as code" has gained traction as organizations have recognized the need for more proactive and integrated approaches to security. Similarly, the idea of "culture as code" reflects the recognition that organizational culture can be a major factor in the success or failure of DevOps initiatives.
The evolution of the "as code" concept has been driven in large part by the rise of cloud computing and the associated shift towards more distributed, dynamic, and scalable systems. These trends have created a need for more efficient, automated, and repeatable ways to manage and secure IT resources, and the "as code" approach is a natural fit for these needs.
Use Cases of "As code"
The "as code" approach can be applied in a wide range of contexts, from small startups to large enterprises, and across various industries. It is particularly relevant in environments where there is a need for speed, scalability, and flexibility, such as in cloud computing, big data, and IoT applications.
One common use case for the "as code" approach is in the management of cloud infrastructure. By treating infrastructure as code, organizations can automate the provisioning and configuration of cloud resources, making it easier to scale up or down in response to demand. This can also help to ensure consistency and repeatability, reducing the risk of configuration errors or drift.
Automated Testing
Another use case for the "as code" approach is in automated testing. By treating test cases and test data as code, teams can automate the execution and validation of tests, making it easier to catch and fix bugs early in the development lifecycle. This can also help to ensure that tests are run consistently and repeatably, reducing the risk of regression errors.
Automated testing is a key component of the DevOps approach, and the "as code" philosophy can help to make this process more efficient and reliable. By treating test cases and test data as code, teams can apply the same version control, testing, and CI/CD practices that they use for application code, resulting in more robust and reliable tests.
Policy as Code
Policy as Code is the process of managing and provisioning machine-readable policy definitions through version-controlled files. This allows for automated enforcement, monitoring, and auditing of policy compliance, as well as version control and auditing of changes to these policies.
Policy as Code is a key component of the DevSecOps movement, which seeks to integrate security and compliance practices into the DevOps workflow. By treating policies "as code," teams can ensure that compliance is considered at every stage of the development lifecycle, rather than being an afterthought or a separate process.
Examples of "As code"
There are many tools and technologies that support the "as code" approach. These range from configuration management tools like Puppet, Chef, and Ansible, to infrastructure provisioning tools like Terraform and CloudFormation, to security and compliance tools like Open Policy Agent.
One example of the "as code" approach in action is the use of Terraform to manage cloud infrastructure. Terraform is a tool for building, changing, and versioning infrastructure safely and efficiently. It can manage existing and popular service providers as well as custom in-house solutions. Configuration files describe to Terraform the components needed to run a single application or your entire datacenter.
Configuration Management Tools
Configuration management tools like Puppet, Chef, and Ansible allow you to manage your servers and other infrastructure devices by writing code, rather than manually configuring each one. These tools allow you to define the desired state of your infrastructure and then automatically enforce that state, making it easier to manage large-scale, distributed systems.
For example, with Puppet, you can write code that specifies which packages should be installed on a server, which services should be running, and other configuration details. Puppet will then ensure that the actual state of the server matches the desired state defined in your code. If anything deviates from the desired state (for example, if a package is accidentally uninstalled), Puppet will automatically correct it.
Infrastructure Provisioning Tools
Infrastructure provisioning tools like Terraform and CloudFormation allow you to manage your cloud infrastructure as code. These tools allow you to define the desired state of your cloud resources (such as virtual machines, storage buckets, and network configurations) in code, and then automatically create, update, or delete these resources as needed to match the desired state.
For example, with Terraform, you can write code that specifies the configuration of a virtual machine, including its size, operating system, network settings, and attached storage. Terraform will then create the virtual machine for you, and if you later change the configuration in your code, Terraform will automatically update the virtual machine to match.
Security and Compliance Tools
Security and compliance tools like Open Policy Agent allow you to manage your security policies and compliance rules as code. These tools allow you to define your policies and rules in code, and then automatically enforce and audit compliance with these policies and rules.
For example, with Open Policy Agent, you can write code that specifies the security policies for your application, such as which users are allowed to access which resources. Open Policy Agent will then enforce these policies at runtime, and can also generate audit logs to help you demonstrate compliance with regulatory requirements.