From 8d7449d25d90e186c658ad235aa889db102f0573 Mon Sep 17 00:00:00 2001
From: "Michael D. Stemle, Jr" <mike.stemle@washpost.com>
Date: Sun, 1 Oct 2023 21:19:40 -0400
Subject: [PATCH] Adding dd api governor (#58)

* Adding a governor to prevent excessive Datadog calls

- Fixed a couple of spots I missed in the CJS migration
- Adding the Governor for HTTP posts to Datadog. It's quasi-configurable, but I haven't exposed the config yet.

* Update CHANGELOG.md
---
 CHANGELOG.md                                  |  4 ++
 __tests__/lib/governors.test.cjs              | 47 +++++++++++++++++++
 ...pander.test.js => input-expander.test.cjs} |  0
 index.cjs                                     |  7 +++
 jest.config.json                              |  3 +-
 lib/governors.cjs                             | 19 +++++++-
 6 files changed, 78 insertions(+), 2 deletions(-)
 create mode 100644 __tests__/lib/governors.test.cjs
 rename __tests__/lib/{input-expander.test.js => input-expander.test.cjs} (100%)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e7a88ac..ee563b2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,10 @@ and this project adheres to [Semantic Versioning].
 
 ## [Unreleased]
 
+### Added
+
+- Added a limit of ten Datadog calls per Workflow step
+
 ### Changed
 
 - Updated dependencies
diff --git a/__tests__/lib/governors.test.cjs b/__tests__/lib/governors.test.cjs
new file mode 100644
index 0000000..d4e2b7f
--- /dev/null
+++ b/__tests__/lib/governors.test.cjs
@@ -0,0 +1,47 @@
+// Need to use inputs for some of our parameters
+const core = require('@actions/core')
+
+const {DatadogPostGovernor } = require('../../lib/governors')
+
+describe('DatadogPostGovernor', () => {
+  test('init', () => {
+    DatadogPostGovernor.init()
+    expect(DatadogPostGovernor.state).toBe(0)
+    expect(DatadogPostGovernor.limit).toBe(10)
+    DatadogPostGovernor.init(42)
+    expect(DatadogPostGovernor.state).toBe(0)
+    expect(DatadogPostGovernor.limit).toBe(42)
+  })
+
+  test('increment', () => {
+    DatadogPostGovernor.init()
+    expect(DatadogPostGovernor.state).toBe(0)
+    expect(DatadogPostGovernor.limit).toBe(10)
+
+    DatadogPostGovernor.increment()
+    expect(DatadogPostGovernor.state).toBe(1)
+
+    DatadogPostGovernor.increment()
+    expect(DatadogPostGovernor.state).toBe(2)
+  })
+
+  test('enforcement', () => {
+    DatadogPostGovernor.init(3)
+    expect(DatadogPostGovernor.state).toBe(0)
+    expect(DatadogPostGovernor.limit).toBe(3)
+    
+    DatadogPostGovernor.increment()
+    expect(DatadogPostGovernor.state).toBe(1)
+    expect(core.setFailed).not.toHaveBeenCalled()
+    DatadogPostGovernor.increment()
+    expect(DatadogPostGovernor.state).toBe(2)
+    expect(core.setFailed).not.toHaveBeenCalled()
+    DatadogPostGovernor.increment()
+    expect(DatadogPostGovernor.state).toBe(3)
+    expect(core.setFailed).not.toHaveBeenCalled()
+
+    DatadogPostGovernor.increment()
+    expect(DatadogPostGovernor.state).toBe(3)
+    expect(core.setFailed).toHaveBeenCalled()
+  })
+})
diff --git a/__tests__/lib/input-expander.test.js b/__tests__/lib/input-expander.test.cjs
similarity index 100%
rename from __tests__/lib/input-expander.test.js
rename to __tests__/lib/input-expander.test.cjs
diff --git a/index.cjs b/index.cjs
index 7855620..71dd277 100644
--- a/index.cjs
+++ b/index.cjs
@@ -1,6 +1,7 @@
 const core = require('@actions/core')
 const { HttpClient } = require('@actions/http-client')
 
+const { DatadogPostGovernor } = require('./lib/governors')
 const { inputsToRegistryDocument } = require('./lib/input-to-registry-document')
 const { validateDatadogHostname } = require('./lib/input-validation')
 const { fetchAndApplyOrgRules } = require('./lib/org-rules')
@@ -11,6 +12,8 @@ const { fetchAndApplyOrgRules } = require('./lib/org-rules')
  * @param {string} config - The config JSON string.
  **/
 const registerWithDataDog = async (apiKey, appKey, ddHost, configJsonStr) => {
+  DatadogPostGovernor.increment()
+
   core.debug(`JSON: ${configJsonStr}`)
   // Prep the auth
   const client = new HttpClient(
@@ -42,6 +45,10 @@ const run = async (configs) => {
     // Extract the API key for DataDog
     const apiKey = core.getInput('datadog-key')
     const appKey = core.getInput('datadog-app-key')
+
+    // Initialize the Post governor to help prevent excessive calls to Datadog
+    DatadogPostGovernor.init()
+
     if (!apiKey || !appKey) {
       return core.setFailed(
         'Both `datadog-key` and `datadog-app-key` are required.',
diff --git a/jest.config.json b/jest.config.json
index 8c93f7a..47b052f 100644
--- a/jest.config.json
+++ b/jest.config.json
@@ -2,7 +2,8 @@
   "collectCoverage": true,
   "coverageDirectory": "coverage",
   "collectCoverageFrom": [
-    "**/lib/**/*.js"
+    "**/lib/**/*.js",
+    "**/lib/**/*.cjs"
   ],
   "testRegex": "(/__tests__/.*|(\\.|/)(test|spec))\\.c?js$",
   "testPathIgnorePatterns": [
diff --git a/lib/governors.cjs b/lib/governors.cjs
index fed53b6..29a467b 100644
--- a/lib/governors.cjs
+++ b/lib/governors.cjs
@@ -1,3 +1,20 @@
-const ddPostGovernor = {
+const core = require('@actions/core')
 
+const DatadogPostGovernor = {
+  state: undefined,
+  limit: undefined,
+  init: (limit = 10) => {
+    DatadogPostGovernor.limit = limit
+    DatadogPostGovernor.state = 0
+  },
+  increment: () => {
+    if (DatadogPostGovernor.state >= DatadogPostGovernor.limit) {
+      return core.setFailed(`Rate limit reached. Please do not exceed ${DatadogPostGovernor.limit} calls to Datadog in a single action.`)
+    }
+    DatadogPostGovernor.state += 1
+  },
+}
+
+module.exports = {
+  DatadogPostGovernor
 }