Getting started

Infracost shows hourly and monthly cost estimates for a Terraform project. This helps users quickly see the cost breakdown and compare different deployment options upfront.

The Infracost GitHub Action or GitLab CI template can be used to automatically add a PR comment showing the cost estimate diff between a pull/merge request and the master branch.

Installation

  1. Install the latest Infracost release:

    brew install infracost

  2. Use our free hosted API for cloud prices by registering for an API key:

    infracost register

    The INFRACOST_API_KEY environment variable can be used to set the API key in CI systems. If you prefer, you can run your own Cloud Pricing API.

  3. Run Infracost using our example Terraform project to see how it works. You can also play with the main.tf file in the example:

    git clone https://github.com/infracost/example-terraform.git
    infracost --tfdir example-terraform/aws

Usage methods

Infracost can be run with different options depending on the use-case, for example:

1. Terraform directory

This is the default method. Point to the Terraform directory using --tfdir and pass any required Terraform flags using --tfflags. Internally Infracost runs Terraform init, plan and show; init requires cloud credentials to be set, e.g. via the usual AWS_ACCESS_KEY_ID environment variables. This method works with remote state too.

infracost --tfdir /path/to/code --tfflags "-var-file=myvars.tfvars"

2. Terraform state file

Point to the Terraform directory using --tfdir and instruct Infracost to use the Terraform state file using --use-tfstate. This implies that you have already run Terraform init, thus Infracost just runs Terraform show, which does not require cloud creds to be set. This method takes less time to run compared with method #1 and also works with remote state.

terraform init
infracost --tfdir /path/to/code --use-tfstate

3. Terraform plan JSON

Point to an existing Terraform plan JSON file using --tfjson. This implies that the user has already run Terraform init, thus Infracost just runs Terraform show, which does not require cloud creds to be set.

cd path/to/code
terraform init
terraform plan -out plan.save .
terraform show -json plan.save > plan.json
infracost --tfjson plan.json

4. Terraform plan file

Point to the Terraform directory and use the Terraform plan. This implies that the user has already run Terraform init, thus Infracost just runs Terraform show, which does not require cloud creds to be set. This method works with remote state too.

cd path/to/code
terraform init
terraform plan -out plan.save .
infracost --tfdir /path/to/code --tfplan plan.save

Useful options

Run infracost --help to see the available options, which include:

--output value Output format (json, table) (default: "table")
--show-skipped Show unsupported resources, some of which might be free (default: false)
--no-color Turn off colored output (default: false)

Environment variables

INFRACOST_API_KEY: Infracost API key, run infracost register to get one.

TERRAFORM_BINARY: used to change the path to the terraform binary:

TERRAFORM_BINARY=~/bin/terraform_0.13 infracost --tfdir /path/to/code

INFRACOST_SKIP_UPDATE_CHECK=true: can be useful in CI/CD systems to skip the Infracost update check.

INFRACOST_LOG_LEVEL: can be set to warn in CI/CD systems to reduce noise.

Standard Terraform environment variables such as TF_* can also be added if required, for example:

TF_CLI_CONFIG_FILE="$HOME/.terraformrc-custom" infracost --tfdir /path/to/code

Terragrunt users

Please subscribe to this GitHub issue for updates as we're working on it.

Terraform Cloud users

Infracost supports Terraform Cloud, AWS S3 or other remote state stores. If you use Terraform Cloud with Remote Execution Mode, please subscribe to this GitHub issue for updates as we're working on supporting it too.

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