Check PR for mistakes in ecosystem page change

.github/policy/files.rego

@@ -0,0 +1,46 @@
+# Expects policy input as provided by:
+# https://api.github.com/repos/open-policy-agent/opa/pulls/${PR_ID}/files
+#
+# Note that the "filename" here refers to the full path of the file, like
+# docs/website/data/integrations.yaml - since that's how it's named in the
+# input we'll use the same convention here.
+
+package files
+
+import future.keywords.in
+
+filenames := [f | f := input[_].filename]
+
+changes := {filename: attributes |
+	c := input[_]
+	filename := c.filename
+	attributes := object.remove(c, ["filename"])
+}
+
+deny["Logo must be placed in docs/website/static/img/logos/integrations"] {
+	"docs/website/data/integrations.yaml" in filenames
+
+	some filename in filenames
+	endswith(filename, ".png")
+	changes[filename].status == "added"
+	directory := substring(filename, 0, last_indexof(filename, "/"))
+	directory != "docs/website/static/img/logos/integrations"
+}
+
+deny["Logo must be a .png file"] {
+	"docs/website/data/integrations.yaml" in filenames
+
+	some filename in filenames
+	changes[filename].status == "added"
+	directory := substring(filename, 0, last_indexof(filename, "/"))
+	directory == "docs/website/static/img/logos/integrations"
+	not endswith(filename, ".png")
+}
+
+last_indexof(string, search) = i {
+	all := [i | chars := split(string, ""); chars[i] == search]
+	count(all) > 0
+	i := all[count(all) - 1]
+} else = -1 {
+	true
+}

.github/policy/files_test.rego

@@ -0,0 +1,44 @@
+package files_test
+
+import data.files.deny
+
+test_deny_logo_if_added_in_wrong_directory {
+	expected := "Logo must be placed in docs/website/static/img/logos/integrations"
+	deny[expected] with input as [
+		{
+			"filename": "docs/website/data/integrations.yaml",
+			"status": "modified",
+		},
+		{
+			"filename": "docs/website/static/img/logos/example.png",
+			"status": "added",
+		},
+	]
+}
+
+test_allow_logo_if_added_in_correct_directory {
+	count(deny) == 0 with input as [
+		{
+			"filename": "docs/website/data/integrations.yaml",
+			"status": "modified",
+		},
+		{
+			"filename": "docs/website/static/img/logos/integrations/example.png",
+			"status": "added",
+		},
+	]
+}
+
+test_deny_logo_if_not_png_file {
+	expected := "Logo must be a .png file"
+	deny[expected] with input as [
+		{
+			"filename": "docs/website/data/integrations.yaml",
+			"status": "modified",
+		},
+		{
+			"filename": "docs/website/static/img/logos/integrations/example.jpg",
+			"status": "added",
+		},
+	]
+}

.github/workflows/pull-request.yaml

@@ -274,3 +274,24 @@ jobs:
       - name: Build
         run: make ci-go-ci-build-linux GOVERSION=${{ matrix.version }}
         timeout-minutes: 30
+
+  # Run PR metadata against Rego policies
+  rego-check-pr:
+    name: Rego PR checks
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v2
+
+      - name: Download OPA
+        uses: infracost/setup-opa@v1
+
+      - name: Test policies
+        run: opa test .github/policy
+
+      - name: Run policy checks on changed files
+        run: |
+          curl --silent --fail --header 'Authorization: Bearer ${{ secrets.GITHUB_TOKEN }}' \
+          https://api.github.com/repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}/files \
+          | opa eval --data .github/policy/files.rego --format values --stdin-input --fail-defined 'data.files.deny[message]'
+