Understanding AWS CloudFormation
CloudFormation is an AWS platform that facilitates automation and deploys infrastructure-as-a-service offerings to help configure and provision multiple AWS resources at a scale that is agile, more productive, and secure. Also, known as cloud automation solution or Infrastructure-as-Code (IaC) tool, it simplifies cloud infrastructure management, replicates infrastructure with ease and speed, without having to individually create and configure resources on AWS. It supports almost all AWS services virtually.
CloudFormation automates the configuration of workloads that run on popular AWS services like EC2 compute, IAM for access control, and S3 storage and aids in prompt and continuous tracking of any changes in the AWS environment.
It is a well-known fact that often on AWS, multiple resources are utilized to manage one particular task. Let us consider a scalable web app with a database at the back-end. This setup will use load balancing, a database instance, and an auto-scaling group as well. However, with AWS CloudFormation, there is no need of creating each resource individually and then configuring them to work as a whole. With CloudFormation, they are created in an integrated fashion that functions as a stack. Eventually, the entire stack can be used or deleted as of a single entity.
With AWS CloudFormation, we usually work with templates and stacks. Templates are created to represent AWS resources and their properties whereas stacks are related resources managed as a single unit. CloudFormation uses these templates as blueprints to build AWS resources. A collection of resources can be created, updated, and deleted by creating, updating, and deleting stacks. For instance, every time an application needs additional availability in a new region, you may want to replicate it. Rather than doing it from scratch each time, you can create a template that establishes the resources you need and simply replicate them to the relevant regions, as many times as necessary.
Changes can be made to the running resources in a stack, by generating a changeset, which is a summary of all the proposed changes. Some amount of customization and small changes to existing templates can be made, to see how changes will impact the ongoing resources, especially for critical resources, before implementing them. Let’s say that your AWS instances are foundationally set up as expected but if auto-scaling is needed for higher performance, not only does AWS CloudFormation allow you to make changes from an existing template with ease and swiftness, but also helps in rolling back to the previous version in case of any issue or hindrance. All AWS CloudFormation templates are saved as text files, which is an added advantage as even non-technical stakeholders can quickly yet effectively track the differences and monitor changes made to the environment. It records comparisons between two or more versions, including the end-to-end synopsis of it.
Benefits of CloudFormation
CloudFormation along with other AWS compatible IaC tools, offer accelerated and structured cloud service management –
- Simultaneous deployment of multiple instances at high-speed using a single template leading to faster deployments.
- CloudFormation templates enable flexibility in terms of scaling resources. Storage or VM instances can be easily scaled up and down based on the requirements at a given point in time.
- When templates are used to define and deploy AWS resources, the same set of reliable, low-risk configurations are invariably applied on multiple instances repeatedly, ensuring consistency, stability and security of applications and services on cloud.
- One single template can manage deployment of independent or several resources, allowing easy integration with AWS services to build complete cloud environments.
- Based on the CloudFormation templates applied, changes in the cloud infra can be tracked to determine how the AWS services and resources have changed with time without having to check logs or timelines.
CloudFormation best practices
AWS CloudFormation can be utilized effectively and to the fullest across the entire workflow with the help of defined best practices recommendations from real-life user experiences. Best practices include –
Planning and organizing:
Organize stacks by lifecycle and ownership, use IAM to control access, and apply cross-stack references to export shared resources. Using modules to reuse resource configurations, verifying quotas for all resource types, and reusing templates to replicate stacks in multiple environments enable consistency and security across the infra deployment lifecycle.
The key is to avoid embedding credentials on templates and ensure utilizing parameter constraints and AWS-specific parameter types. While launching stacks, software applications can be installed and configured on Amazon EC2 instances using the latest helper scripts, and validating templates before using them enhances the building of AWS resources using CloudFormation templates.
All stack resources can be managed via AWS CloudFormation and changesets can be created before updating stacks. Stack policies enable critical stack resources to remain protected from unforeseen updates that may interrupt or replace the resources. Using AWS CloudTrail to log AWS CloudFormation calls is advisable. To review changes and keep a history of AWS resources, use code reviews and revision controls to manage templates.
To summarize, leveraging IaC tools like CloudFormation helps organizations streamline the AWS deployment process. Resource configurations can be effectively defined at the beginning and the same can be deployed multiple times on a need basis. Resources can also be swiftly and predictably updated via changesets, using CloudFormation templates while keeping track of review changes and AWS resources history.