Hi, I’m trying to troubleshoot an issue that is showing up the cost showing up as below picture (basically previous cost is $0). This is definitely wrong since all I did is making the rds instance size larger so should be much lower cost. I did run locally using infracost breakdown, then infracost diff. It shows the correct number. This is my setup in atlantis:

- run: terragrunt show -json "$$PLANFILE" > "$$SHOWFILE"
      - run: |
            infracost breakdown --path="$$SHOWFILE" \
                                --format=json \
                                --log-level=info \
                                --out-file="$$INFRACOST_OUTPUT" \
                                --project-name="$$REPO_REL_DIR"
      - run: |
                    infracost comment github --repo xxx \
                                   --pull-request $$PULL_NUM \
                                   --path $$INFRACOST_OUTPUT \
                                   --github-token $$ATLANTIS_GH_TOKEN \
                                   --tag $$INFRACOST_COMMENT_TAG \
                                   --behavior new

I guess I’m trying to understand generally why we don’t need infracost diff inside cicd set up. I’m using terragrunt with atlantis as my set up. Any help would be appreciated, many thanks

Hi Mengying, the diff isn’t needed because you’re passing a terraform plan json (the

$SHOWFILE

) to

infracost breakdown

and those contain both the current and planned states. Likewise the output of

breakdown

contains the cost breakdown for pervious and new states, which the comment command uses to calculate the diff.

Given that you’re using GitHub, you can also use the GH App (which we made free today): https://www.infracost.io/docs/integrations/github_app/ that’s much simpler to setup

Yep for sure I can look into setting up github app some time.

yeah why don’t you DM me the showfile