Alexis Kestler
Infrastructure as code (IaC) is transforming the way IT teams build and manage infrastructure. IaC applies software development principles like version control, testing, and automation to infrastructure management. With IaC, infrastructure components like servers, databases, networks, and load balancers are provisioned and managed through machine-readable definition files rather than manual processes.
IaC provides major benefits in terms of efficiency, consistency, cost savings, and risk reduction. Leading companies are increasingly adopting IaC practices to improve speed and reliability in infrastructure management.
What is Infrastructure as Code?
Infrastructure as code is the process of managing and provisioning infrastructure through code instead of manual processes. Just like application code, infrastructure code is written in a programming language and contains instructions for deploying and updating infrastructure components.
The IaC codebase serves as the single source of truth for your infrastructure environment. IaC code is reusable, human-readable, and version controlled. Changes to infrastructure are made by modifying code, which is then executed to roll out the required changes. This results in a consistent, repeatable process for managing infrastructure.
IaC tools codify infrastructure components like:
- Virtual machines
- Storage systems
- Network resources
- Load balancers
- Connection configurations
Popular IaC tools include Terraform, Ansible, CloudFormation, Chef, and Puppet.
Benefits of Infrastructure as Code
Adopting infrastructure as code practices provides numerous benefits:
Increased Efficiency and Speed
With IaC, infrastructure can be easily provisioned and managed through code. This eliminates the need for time-consuming manual processes. New infrastructure environments can be stood up in a matter of minutes rather than days or weeks.
Improved Consistency and Compliance
IaC results in consistent, standardized environments. Dev, test, and prod environments can now look exactly alike. Consistency ensures better compliance and reduces issues caused by configuration drift.
Enhanced Collaboration
IaC code can be shared and collaborated on across engineering teams. This improves transparency, enables peer reviews, and results in better designs.
Cost Savings
IaC enables automating infrastructure scaling. Resources can be rapidly spun up or down in response to demand. This results in enhanced infrastructure utilization and lower costs.
Documentation and Version Control
IaC code serves as documentation of the infrastructure environment. And because it is version controlled, all changes are tracked. This improves auditability and enables rollback if issues arise.
Testing and Validation
IaC enables a test-driven approach to infrastructure management. Code can be continuously tested and validated before deployment to production environments.
Security
IaC enables baking in security best practices into infrastructure code. Security policies can be predefined, tested and consistently applied across environments.
Common Infrastructure as Code Tools
There are two main categories of infrastructure as code tools:
Provisioning tools – Used for provisioning infrastructure resources like networks, VMs, storage. Examples include Terraform, CloudFormation.
Configuration management tools – Used for managing configurations and managing software on existing resources. Examples include Ansible, Chef, Puppet.
Here is an overview of some popular open source IaC tools:
Terraform
Terraform is a declarative provisioning tool created by HashiCorp. It is used to define, provision, and manage infrastructure efficiently on various cloud platforms. Terraform code is written in HCL (HashiCorp Configuration Language) and is organized into modules.
Key features:
- Infrastructure provisioning
- Execution plans
- State management
- Cloud vendor agnostic
- Idempotent execution
- Reusable modules
Terraform is great for defining infrastructure components like networks, load balancers, and computing instances. It can be used with configuration tools like Ansible to further configure resources.
Ansible
Ansible is an open source configuration management and automation tool by RedHat. It uses YAML to define configurations and Python for scripting. Ansible connects to nodes via SSH and executes tasks defined in playbooks.
Key features:
- Agentless
- Push-based execution
- Idempotent tasks
- Reusable playbooks and roles
- Simple and readable syntax
Ansible is agentless so there are no agents or servers to install or maintain. It is great for application deployment, configuration management, and orchestration.
CloudFormation
AWS CloudFormation is a declarative IaC tool for provisioning AWS infrastructure resources in a predictable, repeatable manner. Templates are written in JSON or YAML.
Key features:
- Native AWS resource provisioning
- Repeatable infrastructure deployments
- Version control and collaboration
- Free to use
- Integrates with CI/CD workflows
CloudFormation is the best choice for provisioning infrastructure fully within the AWS ecosystem.
Puppet
Puppet is an open source declarative tool for automating system configurations, deployments, and management. Puppet uses its own declarative language to define system states.
Key features:
- Powerful templating language
- Model-driven design
- Continuous compliance enforcement
- Integrates with DevOps tools
- Supports cross-platform configurations
Puppet has a Master-Agent architecture. It is great for configuring and managing Unix-like and Windows systems.
Chef
Chef is an automation and configuration management platform built to automate infrastructure management. Its scripts called recipes define system configuration, which are executed on nodes using chef-client.
Key features:
- Uses Ruby DSL for scripting
- Integrates with cloud platforms
- Powerful templating features
- Cookbooks for reusable components
- Supports policy-based compliance
Chef works by executing recipes on nodes via ssh or winrm. It is well-suited for automating policies, processes, and application deployments.
IaC Best Practices
Here are some best practices to follow when adopting infrastructure as code:
Start Small and Build Up
Begin with a small, non-critical environment or application stack. Build up your IaC skills on lower risk projects first before expanding.
Use Modules and Libraries
Break your IaC code down into reusable, modular components like templates, macros, modules, and libraries. This improves readability and collaboration.
Validate and Test Frequently
Make validation and testing a priority. Continuously check for errors and inconsistencies in your IaC code to prevent deployment failures.
Use Version Control
Store IaC code in a version control system like Git. This enables collaborating, tracking changes, and rolling back if needed.
Automate Testing
Automated testing of IaC code is critical. Use unit, integration, and acceptance testing frameworks to validate code quality.
Document Thoroughly
Document your IaC code repositories thoroughly. Include comments in code, READMEs, design docs, etc. to capture institutional knowledge.
Manage Secrets Securely
Never store passwords, keys, or tokens directly in IaC code. Use secret management services to securely inject secrets at runtime.
Monitor and Audit Changes
Watch for IaC code changes and drift through monitoring and audits. Continuously check that defined infrastructure state matches actual state.
Collaborate Across Teams
Promote collaboration between developers, operations, and security teams on IaC code. This results in more effective designs.
Getting Started with Infrastructure as Code
Adopting infrastructure as code requires planning and cultural changes in addition to new tools and skills. Here are some recommendations for teams getting started:
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Train – Provide training on IaC concepts and tools for your teams. Have engineers build skills through hands-on labs and projects.
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Start small – Focus initial IaC work on low-risk applications and services. Learn techniques at smaller scale before expanding.
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Develop workflows – Define processes and workflows for IaC code review, testing, validation, and deployment.
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Establish patterns – Standardize IaC code patterns, modules, and architecture. Promote reusability across applications and teams.
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Version control – Manage IaC code in version control with documented commit policies. This enables change tracking and collaboration.
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Automate testing – Implement automated testing tools and frameworks to validate IaC code quality and prevent errors.
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Monitor results – Monitor IaC deployments and infrastructure state. Report on improvements in efficiency, quality, and outcomes.
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Expand use – Once successes are achieved, expand IaC adoption across the organization.
Key Concepts in Infrastructure as Code
Here are some key concepts related to infrastructure as code:
Declarative vs Imperative IaC
Declarative IaC – Desired end state is declared e.g. Terraform, CloudFormation. The tool handles execution.
Imperative IaC – Code defines specific commands to execute in order e.g. Ansible, Chef. More procedural.
Mutable vs Immutable Infrastructure
Mutable – Existing servers are modified via tools like Chef, Ansible. Allows for configuration drift over time.
Immutable – Servers are replaced with new instances built from predefined images. Prevents configuration drift.
Idempotence
Idempotence means infrastructure can be applied repeatedly with the same outcome. Small incremental changes can be applied safely.
Reusable Modules
Breaking IaC code down into reusable modules improves code organization, testing, and collaboration between teams.
State Management
IaC tools maintain state to know the actual status of infrastructure and sync it with desired state defined in code.
Conclusion
Infrastructure as code is essential for managing infrastructure efficiently as organizations scale. IaC improves speed and consistency while reducing risk and manual effort. Leading companies are implementing IaC tools like Terraform and Ansible to stay competitive. To be successful, organizations need to invest in training, testing frameworks, and new processes to fully leverage IaC.
