There are several open source tools available to manage infrastructure as code that are backed by large communities of contributors with enterprise offering and good documentation. Why do we choose Terraform and what makes it unique / stand out? Terraform is used to provision an infrastructure and manage the infrastructure changes by versioning. It can manage components such as compute instances, storage, and networking, as well as high-level components such as DNS entries etc.

Good Fit for Cloud Agnostics Strategy

Enterprises would be interested to mitigate the availability risk of mission critical system in cloud by spreading their services across multiple cloud providers. Also, enterprises would always look for avenues to reduce their infrastructure cost by moving away from vendor locking situation. Terraform comes as savior for these use cases by being cloud-agnostic and allows a single configuration to be used to manage multiple providers, and to even handle cross-cloud dependencies by simplifying management and orchestration.

An Orchestration Tool

Chef, Puppet, Ansible, and SaltStack are all “configuration management” tools that are designed to install and manage software on existing servers whereas Terraform is an “orchestration tool” that is designed to provision the servers and leaving the configuring job to other tools. While there might be certain overlapping features between orchestration and configuration tools, each tool is going to be a better fit for certain use case. For example, when an infrastructure is dominated by Containers, all you need to do is provision a bunch of servers, then an orchestration tool like Terraform is typically going to be a better fit than a configuration management tool

Combat Configuration Drift

While configuration tools are best known to combat the configuration drift in the infrastructure, they are mostly used to manage a subset of machine’s state that will lead to some gap in the infrastructure state. The management will see diminishing returns to close those gaps against the matter that needs the most for daily operations. This set of issues can be mitigated with Terraform along with Containers.

For example, if you tell configuration tool to install a new version of OpenSSL, it’ll run the software update on your existing servers and the changes will happen in-place. Over time, as you apply more and more updates, each server builds up a unique history of changes, causing configuration drift. If you’re using Docker and an orchestration tool such as Terraform, the docker image is already built ready for the new servers. A new server will be deployed and then uninstall the old servers. All the server states will be maintained by Terraform. This approach reduces the likelihood of configuration drift bugs.

Conclusion

Overall, Terraform is an open source and cloud-agnostic orchestration tool with salient features. While it might be a less mature tool compared to other tools in the market, Terraform is still a good candidate to meet a specific set of requirements.