No one has to convince you that using a version control system with a configuration management tool for managing your project is a completely sensible thing these days. This makes provisioning a lot easier and more efficient. Now, two of the most commonly mentioned names for provisioning are Ansible vs Terraform. However, these two tools aren’t exactly interchangeable.
Continue reading below to understand better about:
– What Ansible and Terraform actually are,
– The distinctive capabilities and benefits of Ansible and Terraform,
– The limitations of each tool, and
– Which tool that is more recommended for you.
Terraform’s Primary Capabilities
First of all, we should point out that there are a lot of people who use both Ansible and Terraform, as these two tools are actually complementary to each other. Ansible is primarily used for configuration management, whereas Terraform is primarily implemented for infrastructure provisioning. See also: Ansible vs Chef.
Let’s start with Terraform. Terraform is more of an infrastructure provisioning tool, which some people refer to as an orchestration tool. Terraformis responsible for ensuring that there is the right number of units in the network and that they are functioning properly. Also, when there is an issue with a unit, the tool may remove the misbehaving unit and replace it with another. Terraform is focused on the end result in making the environment always in the correct state.
Terraform usually stores the correct state for the environment and periodically checks the current state of the environment. If there is anything out of order, it automatically provides the necessary resources to restore the state. Hence, Terraform is fantastic for an environment that requires a very steady state. You can download the tool from Terraform’s official web page.
Ansible’s Unique Features
On the other hand, most people use Ansible for configuration management. This tool acts like a repairman that is responsible for tuning and configuring every unit so that the unit can work properly. This tool may also be used to ensure that every unit is always up to date with the latest changes in the project development. When there is a problem with a unit, Ansible doesn’t replace it with another unit entirely; it works to repair it.
Ansible is very easy and simple to use. It has an agentless architecture, which means that it does not need to install any client software on the nodes. It only needs OpenSSH and WinRM or Python in order to control the nodes remotely.
Note that Ansible can also be seen as a hybrid between an infrastructure provisioning tool and a configuration management tool. That’s because it does have some orchestration capabilities. However, it is very limited in this aspect. It does not record state, which for some people is the core functionality needed. Terraform is better in this aspect due to the more advanced state management capabilities.
There is also a significant difference between these two tools’ languages. You need to know that Terraform is strictly declarative. A declarative language describes exactly what is needed, and not the process to achieve the result. You define the environment precisely. Whenever the environment changes, Terraform will restore it to what you’ve defined.
On the other hand, Ansible supports both declarative and procedural languages. A procedural-style configuration describes specifically the steps to be taken rather than the end result. You can use the modules which perform declarative-style configurations, or enter ad-hoc commands for procedural-style configurations. Make sure that you read the documentation to ensure that you understand when to use declarative/procedural along with the behavior to expect.
Ansible vs Terraform
|- Mainly for configuration management||- Mainly for infrastructure provisioning|
|- Easy deployment and flexible configuration capabilities||- Advanced state management capabilities|
|- Can’t record states||- Records states|
|- Supports both procedural and declarative||- Strictly declarative|
If you only need a configuration management tool that can keep your source codes updated with the latest iterations, Ansible is sufficient. However, if you need an infrastructure provisioning tool that can keep your environment in a steady state, Terraform should be your choice. Terraform has more advanced state management capabilities.