Why has Terraform become a more popular tool compared to Salt?

Terraform focuses on declaring infrastructure (IaC), providing a universal syntax for various cloud providers and on-premise solutions. Salt was originally oriented towards configuration management, although it has IaC capabilities.

Main differences:

• Purpose: Terraform — Infrastructure as Code (IaC), Salt — configuration management with IaC elements.
• Approach: Terraform uses a declarative approach to describe the desired state of infrastructure. Salt uses both declarative (state files) and imperative (execution modules) approaches.
• Ecosystem: Terraform has an extensive and growing ecosystem of providers, supporting a large number of cloud services and third-party systems. Salt also has modules, but their number and coverage are generally inferior to Terraform.
• State: Terraform tracks the state of the deployed infrastructure in a state file (.tfstate), allowing for more predictable planning and applying of changes. Salt also supports state via state files, but its mechanism differs.
• HCL simplicity: HashiCorp Configuration Language (HCL) in Terraform is considered more intuitive for describing infrastructure than YAML or SLS files used in Salt.
• Use for Provisioning and Day 2 Operations: Terraform is oriented towards creating and basic management of infrastructure, while Salt is more suitable for subsequent configuration and management of server lifecycle (Day 2 operations). Although Terraform also has management capabilities, its main strength lies in Provisioning.

// Example of describing an EC2 resource in Terraform
resource "aws_instance" "web_server" {
  ami           = "ami-0abcdef1234567890"
  instance_type = "t2.micro"

  tags = {
    Name = "WebServer"
  }
}

# Example of a basic SaltStack state file for installing a package
nginx:
  pkg.installed

Terraform's popularity has grown due to its focus on IaC, broad multi-cloud support, and a relatively low entry barrier for infrastructure deployment. Salt remains a powerful configuration management tool, but in the context of pure IaC, Terraform often proves to be the more preferred choice.