Add runtime and memorysize tags to enhanced metrics

src/index.spec.ts

@@ -189,7 +189,7 @@ describe("datadog", () => {
     await wrapped({}, mockContext, () => {});
 
     expect(mockedIncrementInvocations).toBeCalledTimes(1);
-    expect(mockedIncrementInvocations).toBeCalledWith(mockARN);
+    expect(mockedIncrementInvocations).toBeCalledWith(mockContext);
 
     await wrapped({}, mockContext, () => {});
     await wrapped({}, mockContext, () => {});
@@ -213,8 +213,8 @@ describe("datadog", () => {
     expect(mockedIncrementInvocations).toBeCalledTimes(1);
     expect(mockedIncrementErrors).toBeCalledTimes(1);
 
-    expect(mockedIncrementInvocations).toBeCalledWith(mockARN);
-    expect(mockedIncrementErrors).toBeCalledWith(mockARN);
+    expect(mockedIncrementInvocations).toBeCalledWith(mockContext);
+    expect(mockedIncrementErrors).toBeCalledWith(mockContext);
   });
 
   it("increments errors and invocations with config setting", async () => {
@@ -230,8 +230,8 @@ describe("datadog", () => {
     expect(mockedIncrementInvocations).toBeCalledTimes(1);
     expect(mockedIncrementErrors).toBeCalledTimes(1);
 
-    expect(mockedIncrementInvocations).toBeCalledWith(mockARN);
-    expect(mockedIncrementErrors).toBeCalledWith(mockARN);
+    expect(mockedIncrementInvocations).toBeCalledWith(mockContext);
+    expect(mockedIncrementErrors).toBeCalledWith(mockContext);
   });
 
   it("doesn't increment enhanced metrics without env var or config", async () => {

src/index.ts

@@ -81,12 +81,12 @@ export function datadog<TEvent, TResult>(
         listener.onStartInvocation(event, context);
       }
       if (finalConfig.enhancedMetrics) {
-        incrementInvocationsMetric(context.invokedFunctionArn);
+        incrementInvocationsMetric(context);
       }
     },
     async (event, context, error?) => {
       if (finalConfig.enhancedMetrics && error) {
-        incrementErrorsMetric(context.invokedFunctionArn);
+        incrementErrorsMetric(context);
       }
       // Completion hook, (called once per handler invocation)
       for (const listener of listeners) {

src/metrics/enhanced-metrics.spec.ts

@@ -0,0 +1,63 @@
+import { Context } from "aws-lambda";
+import { _resetColdStart } from "../utils/cold-start";
+import { getProcessVersion } from "../utils/process-version";
+import { getEnhancedMetricTags, getRuntimeTag } from "./enhanced-metrics";
+
+jest.mock("../utils/process-version");
+
+const mockedGetProcessVersion = getProcessVersion as jest.Mock<string>;
+
+const mockARN = "arn:aws:lambda:us-east-1:123497598159:function:my-test-lambda";
+const mockContext = ({
+  invokedFunctionArn: mockARN,
+  memoryLimitInMB: "128",
+} as any) as Context;
+
+describe("getRuntimeTag", () => {
+  it("returns a null runtime tag when version is not recognized", () => {
+    mockedGetProcessVersion.mockReturnValue("v6.2.3");
+    expect(getRuntimeTag()).toBe(null);
+  });
+
+  it("returns the expected tag for v8.10", () => {
+    mockedGetProcessVersion.mockReturnValue("v8.10.0");
+    expect(getRuntimeTag()).toBe("runtime:nodejs8.10");
+  });
+
+  it("returns the expected tag for v10.x", () => {
+    mockedGetProcessVersion.mockReturnValue("v10.1.0");
+    expect(getRuntimeTag()).toBe("runtime:nodejs10.x");
+  });
+});
+
+describe("getEnhancedMetricTags", () => {
+  beforeEach(() => {
+    _resetColdStart();
+  });
+  afterEach(() => {
+    _resetColdStart();
+  });
+
+  it("generates tag list with runtime", () => {
+    mockedGetProcessVersion.mockReturnValue("v8.10.0");
+    expect(getEnhancedMetricTags(mockContext)).toStrictEqual([
+      "region:us-east-1",
+      "account_id:123497598159",
+      "functionname:my-test-lambda",
+      "cold_start:true",
+      "memorysize:128",
+      "runtime:nodejs8.10",
+    ]);
+  });
+
+  it("doesn't add runtime tag if version is unrecognized", () => {
+    mockedGetProcessVersion.mockReturnValue("v6.3.2");
+    expect(getEnhancedMetricTags(mockContext)).toStrictEqual([
+      "region:us-east-1",
+      "account_id:123497598159",
+      "functionname:my-test-lambda",
+      "cold_start:true",
+      "memorysize:128",
+    ]);
+  });
+});

src/metrics/enhanced-metrics.ts

@@ -1,16 +1,61 @@
 import { getEnvValue, sendDistributionMetric } from "../index";
 
+import { Context } from "aws-lambda";
 import { parseTagsFromARN } from "../utils/arn";
 import { getColdStartTag } from "../utils/cold-start";
+import { getProcessVersion } from "../utils/process-version";
 
 const ENHANCED_LAMBDA_METRICS_NAMESPACE = "aws.lambda.enhanced";
 
-export function incrementInvocationsMetric(functionARN: string): void {
-  const tags = [...parseTagsFromARN(functionARN), getColdStartTag()];
-  sendDistributionMetric(`${ENHANCED_LAMBDA_METRICS_NAMESPACE}.invocations`, 1, ...tags);
+// Same tag strings added to normal Lambda integration metrics
+enum RuntimeTagValues {
+  Node8 = "nodejs8.10",
+  Node10 = "nodejs10.x",
 }
 
-export function incrementErrorsMetric(functionARN: string): void {
-  const tags = [...parseTagsFromARN(functionARN), getColdStartTag()];
-  sendDistributionMetric(`${ENHANCED_LAMBDA_METRICS_NAMESPACE}.errors`, 1, ...tags);
+/**
+ * Uses process.version to create a runtime tag
+ * If a version cannot be identified, returns null
+ * See https://docs.aws.amazon.com/lambda/latest/dg/lambda-runtimes.html
+ */
+export function getRuntimeTag(): string | null {
+  const processVersion = getProcessVersion();
+  let processVersionTagString: string | null = null;
+
+  if (processVersion.startsWith("v8.10")) {
+    processVersionTagString = RuntimeTagValues.Node8;
+  }
+
+  if (processVersion.startsWith("v10")) {
+    processVersionTagString = RuntimeTagValues.Node10;
+  }
+
+  if (!processVersionTagString) {
+    return null;
+  }
+
+  return `runtime:${processVersionTagString}`;
+}
+
+export function getEnhancedMetricTags(context: Context): string[] {
+  const tags = [
+    ...parseTagsFromARN(context.invokedFunctionArn),
+    getColdStartTag(),
+    `memorysize:${context.memoryLimitInMB}`,
+  ];
+
+  const runtimeTag = getRuntimeTag();
+  if (runtimeTag) {
+    tags.push(runtimeTag);
+  }
+
+  return tags;
+}
+
+export function incrementInvocationsMetric(context: Context): void {
+  sendDistributionMetric(`${ENHANCED_LAMBDA_METRICS_NAMESPACE}.invocations`, 1, ...getEnhancedMetricTags(context));
+}
+
+export function incrementErrorsMetric(context: Context): void {
+  sendDistributionMetric(`${ENHANCED_LAMBDA_METRICS_NAMESPACE}.errors`, 1, ...getEnhancedMetricTags(context));
 }

src/utils/process-version.ts

@@ -0,0 +1,3 @@
+export function getProcessVersion() {
+  return process.version;
+}