v0.10.0

What's new?

Back in February 2022, we started an experiment to estimate costs by parsing Terraform HCL code directly. We're excited to announce that the experiment worked! So in v0.10 we've removed the experimental --terraform-parse-hcl flag and made HCL parsing the default behavior.

Going forward, we'll support two ways to run Infracost with Terraform via --path:

1. Parsing HCL code (directory): this is the default and recommended option as it has the following 5 key benefits.

   # Terraform variables can be set using --terraform-var-file or --terraform-var
   infracost breakdown --path /code

2. Parsing plan JSON file: this will continue to work as before.

   cd /code
   terraform init
   terraform plan -out tfplan.binary
   terraform show -json tfplan.binary > plan.json
   
   infracost breakdown --path plan.json

1. Faster CLI

Infracost can now generate cost estimates without needing a Terraform plan. This removes our dependency on the Terraform binary altogether, which means no more terraform init or terraform plan.

That, in turn, means a super-fast CLI: Infracost used to take around 50 seconds to run on our internal Terraform mono-repo, that's now reduced to 2 seconds. 🚀

2. No cloud creds needed

Running terraform plan requires users to have cloud credentials and Terraform secrets. The main reason we created the Infracost CLI first, instead of a web API, was so it could parse the Terraform plan JSON locally to extract cost-related parameters (e.g. instance type). Thus credentials and secrets were not sent anywhere.

Whilst this worked and was safe, it still posed a question: is there a way to avoid setting credentials or secrets altogether? Removing our dependency on terraform plan gave us a way to do that.

3. Cost estimates everywhere

Not needing cloud credentials, or even knowledge of how to generate a Terraform plan, means that any engineer who has access to code repos can generate cost estimates!

This also opens the door for cost estimates to be put everywhere: Infra-as-Code repo readmes, Terraform module readmes, Visual Studio, and even in continuous integration systems where a Terraform plan does not exist (not everyone runs Terraform via continuous deployment systems).

To make infracost diff work without a Terraform plan, we introduced a new --compare-to infracost-base.json flag. This enables a git-based cost diff to be produced, e.g.:

git checkout main
infracost breakdown --path /code --format json --out-file infracost-base.json

git checkout my-branch
infracost diff --path /code --compare-to infracost-base.json

4. Compare Infracost runs

The infracost diff command can now also be used to compare Infracost runs. Assuming you generated the files infracost-last-week.json and infracost-today.json using the infracost breakdown --path /code --format json command, you can compare them using:

infracost diff --path infracost-today.json --compare-to infracost-last-week.json

5. Detect multi-project repos

Setting the --path flag to a top-level repo directory will now attempt to process all projects automatically by:

1. Looking at the specified path or in any of the subdirectories with a depth less than 5.
2. Processing Terraform variable files with the .auto.tfvars extension (similar to what Terraform does).
3. Processing environment variables with a TF_VAR_ prefix (similar to what Terraform does).

If this does not work for your use-case, use a config-file and run infracost breakdown --config-file=infracost.yml, for example:

# infracost.yml
version: 0.1
projects:
  - path: prod
    terraform_var_files:
      - prod.tfvars
      - us-east.tfvars

  - path: dev
    terraform_var_files:
      - dev.tfvars

Migration guides

👉👉👉 See the migration guides in the docs for migrating specific CI systems to use the new v0.10 Infracost version.

Removed functionality

See this docs section.

Known issues

See this docs section.

Other changes

New resources

Google

• Support for google_compute_per_instance_config by @golgeek in #1645
• Support for google_compute_region_per_instance_config by @golgeek in #1657

AWS

• Support for reservation in db_instance by @carmeloriolo in #1653

Enhancements

• Add a better error message for errors originating from the Terragrunt libs by @aliscott in #1666
• Add breakdown path hint by @tim775 in #1673
• Fallback to the workspace defined by TF env for remote var loading by @hugorut in #1679
• Enable -no-color option by default for CI by @vdmgolub in #1628

Fixes

• Redis instance monthly pricing by @vdmgolub in #1627
• Mark azure b1 type machine as free by @tim775 in #1629
• Resolve SNS Topic notification price filters by @vdmgolub in #1633
• Solve support for references with for_each by @golgeek in #1640
• Rework reference mapping by @golgeek in #1660
• Computation of local scratch disk in GCP by @golgeek in #1655
• MSSQL Database License Type retrieval by @vdmgolub in #1664
• Update GCE inter-region egress filter by @tim775 in #1674
• Show only one cost component for Google Compute Address by @vdmgolub in #1639

New Contributors

• @golgeek made their first contribution in #1640
• @carmeloriolo made their first contribution in #1653

We also want to give a massive thank you to every community member who has helped us with any HCL parsing issues by reporting them and helping us reproduce them. Finding these issues would not have been possible without this 🎉.