HashiCorp Configuration Language (HCL)
An HashiCorp Configuration Language (HCL) is a simple human-readable high-level configuration DSL.
- Context:
- It can (typically) be a Declarative Programming Language (because it is a domain-specific language).
- It can be a Structural Language, Expression Language and a Template Language.
- …
- Counter-Example(s):
- Puppet DSL: A configuration language used in the Puppet infrastructure automation platform for defining the desired state of managed nodes.
- Chef Cookbooks: A configuration language used in the Chef infrastructure automation platform for defining the desired state of managed nodes.
- See: JSON, Terraform.
References
2022
- https://chat.openai.com/chat
- QUOTE: HashiCorp Configuration Language (HCL) is a programming language designed to be easy to use and read. It is used by several tools developed by HashiCorp, including Terraform, Packer, and Nomad. HCL is a declarative language, which means that it describes the desired state of a system rather than specifying the steps required to achieve that state. It is typically used to define infrastructure as code, which means that it can be used to automate the creation, modification, and management of infrastructure resources such as servers, networks, and storage.
In HCL, users can define resources and their configurations, specify dependencies between resources, and write scripts to perform tasks such as installing software or running tests. HCL is a simple, human-readable language that uses familiar syntax and concepts, making it easy for users to learn and use. It is also designed to be easily extensible, allowing users to create their own custom resource types and functions.
- QUOTE: HashiCorp Configuration Language (HCL) is a programming language designed to be easy to use and read. It is used by several tools developed by HashiCorp, including Terraform, Packer, and Nomad. HCL is a declarative language, which means that it describes the desired state of a system rather than specifying the steps required to achieve that state. It is typically used to define infrastructure as code, which means that it can be used to automate the creation, modification, and management of infrastructure resources such as servers, networks, and storage.
2022
- https://chat.openai.com/chat
- Q: How is HCL a combination of Structural, Expression and a Template language?
- A: HCL (HashiCorp Configuration Language) is a configuration language developed by HashiCorp that is designed to be both human and machine readable, and to be able to express complex configurations in a clear and concise way.
As a structural language, HCL has a specific syntax and structure that must be followed in order to be valid. It uses various elements such as blocks, brackets, and keys to define the structure of the configuration file.
As an expression language, HCL allows users to include variables and functions in their configuration files. This allows for the use of dynamic values and the ability to perform calculations and transformations on data.
As a template language, HCL allows users to include templates in their configuration files, which can be used to create reusable configurations and reduce duplication of code. Templates can be used to define common configurations that can be shared across different resources or environments.
Overall, HCL combines the features of a structural, expression, and template language to provide a flexible and powerful configuration language that can be used to define complex infrastructure in a clear and concise way. ...
2022
- https://chat.openai.com/chat
- Q: provide some examples of HCL code.
- A: This code defines an AWS security group resource and uses a "for" loop to create a separate security group for each element in the "security_groups" variable. The "for_each" parameter allows the resource block to iterate over the elements in the variable and create a security group for each one. The "count" and "count.index" variables are used to assign the security group names based on the elements in the list.:
variable "security_groups" {
default = ["sg-12345678", "sg-87654321"]
}
#
resource "aws_security_group" "example" {
count = "${length(var.security_groups)}"
vpc_id = "vpc-12345678"
name = "${element(var.security_groups, count.index)}"
#
for_each = {
for sg in var.security_groups : sg => {}
}
#
ingress {
from_port = 80
to_port = 80
protocol = "tcp"
cidr_blocks = ["0.0.0.0/0"]
}
}