Terraform Cost Estimator

Helps you to estimate costs of Terraform Plans and right now is focused on the azurerm Terraform Provider. Note these are estimates only (not actual costs) based on "Pay-as-you-Go" pricing. The point of this API is only so you have an estimate, not a guarantee of potential future costs. If you're looking for other pricing schemes, such as "reserved", "DevTest", or if your company has an agreement with a cloud provider that gives you a discount off of standard "Pay-as-you-Go" list prices this will not be reflected here. Hopefully, if you are looking for one of these pricing schemes, this API should at least provide you with an upper-bound. However, it in no way represents a guarantee of prices between you and your cloud provider.

Can I use this for more cloud providers than Azure?

It is definitely designed to provide this functionality, but at present since I work at a company that uses Azure I'm focused on that. That being said, PR's welcome!

Usage

One more time for emphasis, this is only an estimate of expected future cloud costs!

terraform plan -out=plan.tfplan > /dev/null && terraform show -json plan.tfplan  | curl -s -X POST -H "Content-Type: application/json" -d @- https://api-dev.pricing.tf/estimate

Response

{
    "unsupported_resources": [
        "azurerm_network_interface.example"
    ],
    "unestimateable_resources": [
        "azurerm_resource_group.example",
        "azurerm_subnet.example",
        "azurerm_virtual_network.example"
    ],
    "estimate_summary": {
        "hourly_cost_usd": 0.114,
        "monthly_cost_usd": 83.22,
        "yearly_cost_usd": 998.64
    }
}

The response provides:

• unsupported_resources to let you know which resources weren't priced
• estimate_summary which contains the Hourly, Monthly, and Yearly additional cost based on this Terraform plan
• unestimateable_resources to let you know which resources are not currently able to be estimated based on this terraform plan

Note: currently "monthly" and "yearly" prices are only calculated as a multiple of hours. 1 Month = 730 Hours and 1 Year = 8760 Hours.

Security

The code is all here and executes in a serverless function, you can read for yourself and see that we're not storing/logging anything you send. 😄

Supported Resources

	Resource Name	Area
[x]	azurerm_linux_virtual_machine	Compute
[x]	azurerm_windows_virtual_machine	Compute
[x]	azurerm_virutal_machine	Compute
[x]	azurerm_virutal_machine_scale_set	Compute
[x]	azurerm_linux_virutal_machine_scale_set	Compute
[x]	azurerm_windows_virutal_machine_scale_set	Compute
[x]	azurerm_kubernetes_cluster	Containers

Unestimateable Resources

	Resource Name	Area
[x]	azurerm_resource_group	Management
[x]	azurerm_virtual_network	Networking
[x]	azurerm_subnet	Networking
[x]	azurerm_network_interface	Networking

A side note on billable units of measure:

Not all billable resources in Azure are tied to an hourly price. For example, consider VNETs/egress, StorageAccount Blob Storage consumed size, or anything tied to API call count like KeyVault. These resources depend on further consumption after provisioning, so they are in-effect unestimateable from the standpoint of this API. In theory, one could derive an estimate based on average consumption across all Azure usage, but I don't work for Microsoft/nor have access to that data. So, they will probably remain unestimated unless you have a good idea and want to contribute!

To Dev

• Ensure that go >= 1.13 and serverless 2.x is installed on your machine
• Make a PR (add a test too)
• Assign me (zparnold) and I will try to get it merged and deployed.

Adding Resources to Price

The api/pricers/ folder is where a collection of interfaces of type Pricer are implemented. The only function necessary to implement this interface is GetHourlyPrice() which returns a float64. Should you want to use the existing price database (Dynamo) take a look at the resource enumeration section below. There is also a prices.csv that should give you a full list of priceable objects in Azure returned by their public API here: https://docs.microsoft.com/en-us/rest/api/cost-management/retail-prices/azure-retail-prices

To add another resource to be priced:

• Add a new file, preferably in the api/pricers/ folder using a name that would help others understand it
• Implement the function from above
• Add a case statement in the api/main.go which binds the terraform resource name to the pricer (copy one from the method.)

The path to 1.0 (and prod)

Status	Task
[x]	Integration tests exist
	Integration tests in CI pipeline
	Automated deployment in CI Pipeline
[x]	Basic compute resources supported
	Basic storage resources supported
	Estimateable networking resources supported
	Some PaaS or SaaS resources supported maybe? (Azure App Services, Redis, Azure Functions, AKS, ACI)