💸 cost: Adds infracost workflow, app hasn't been working well (#12)

Author: bendoerr

.github/workflows/infracost.yml

@@ -0,0 +1,57 @@
+name: Infracost
+
+on:
+  pull_request:
+    branches: [main]
+    types: [opened, synchronize, reopened]
+
+permissions:
+  contents: read
+
+jobs:
+  report:
+    runs-on: ubuntu-latest
+
+    permissions:
+      contents: read
+      pull-requests: write
+
+    steps:
+      - uses: infracost/actions/setup@e9d6e6cd65e168e76b0de50ff9957d2fe8bb1832 # v3.0.1
+        with:
+          api-key: ${{ secrets.INFRACOST_API_KEY }}
+
+      # Checkout the base branch of the pull request (e.g. main/master).
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+        with:
+          ref: ${{ github.event.pull_request.base.ref }}
+
+      - run: |
+          infracost breakdown --config-file=infracost.yml \
+                              --format=json \
+                              --out-file=/tmp/infracost-base.json
+
+      # Checkout the current PR branch so we can create a diff.
+      - uses: actions/checkout@692973e3d937129bcbf40652eb9f2f61becf3332 # v4.1.7
+
+      # Generate an Infracost diff and save it to a JSON file.
+      - run: |
+          infracost diff  --config-file=infracost.yml \
+                          --format=json \
+                          --compare-to=/tmp/infracost-base.json \
+                          --out-file=/tmp/infracost.json
+
+      # Posts a comment to the PR using the 'update' behavior.
+      # This creates a single comment and updates it. The "quietest" option.
+      # The other valid behaviors are:
+      #   delete-and-new - Delete previous comments and create a new one.
+      #   hide-and-new - Minimize previous comments and create a new one.
+      #   new - Create a new cost estimate comment on every push.
+      # See https://www.infracost.io/docs/features/cli_commands/#comment-on-pull-requests for other options.
+      - run: |
+          infracost comment github --path=/tmp/infracost.json \
+                                   --repo="${GITHUB_REPOSITORY}" \
+                                   --github-token=${{github.token}} \
+                                   --pull-request=${{github.event.pull_request.number}} \
+                                   --behavior=update \
+                                   --show-skipped