feat(http-plugin): add options to disable new spans if no parent #931

open-telemetry · Apr 15, 2020 · 344d9c0 · 344d9c0
1 parent 8e56923
commit 344d9c0
Show file tree

Hide file tree

Showing 4 changed files with 132 additions and 7 deletions.
diff --git a/packages/opentelemetry-plugin-http/README.md b/packages/opentelemetry-plugin-http/README.md
@@ -55,6 +55,8 @@ Http plugin has few options available to choose from. You can set the following:
 | [`ignoreIncomingPaths`](https://github.com/open-telemetry/opentelemetry-js/blob/master/packages/opentelemetry-plugin-http/src/types.ts#L28) | `IgnoreMatcher[]` | Http plugin will not trace all incoming requests that match paths |
 | [`ignoreOutgoingUrls`](https://github.com/open-telemetry/opentelemetry-js/blob/master/packages/opentelemetry-plugin-http/src/types.ts#L28) | `IgnoreMatcher[]` | Http plugin will not trace all outgoing requests that match urls |
 | [`serverName`](https://github.com/open-telemetry/opentelemetry-js/blob/master/packages/opentelemetry-plugin-http/src/types.ts#L28) | `string` | The primary server name of the matched virtual host. |
+| `requireParentforOutgoingSpans` | Boolean | Require that is a parent span to create new span for outgoing requests. |
+| `requireParentforIncomingSpans` | Boolean | Require that is a parent span to create new span for incoming requests. |
 
 ## Useful links
 - For more information on OpenTelemetry, visit: <https://opentelemetry.io/>

diff --git a/packages/opentelemetry-plugin-http/src/http.ts b/packages/opentelemetry-plugin-http/src/http.ts
@@ -22,8 +22,15 @@ import {
   SpanKind,
   SpanOptions,
   Status,
+  SpanContext,
+  TraceFlags,
+  NoopSpan,
 } from '@opentelemetry/api';
-import { BasePlugin } from '@opentelemetry/core';
+import {
+  BasePlugin,
+  NoRecordingSpan,
+  getExtractedSpanContext,
+} from '@opentelemetry/core';
 import {
   ClientRequest,
   IncomingMessage,
@@ -57,6 +64,12 @@ export class HttpPlugin extends BasePlugin<Http> {
   /** keep track on spans not ended */
   private readonly _spanNotEnded: WeakSet<Span>;
 
+  private readonly _emptySpanContext: SpanContext = {
+    traceId: '',
+    spanId: '',
+    traceFlags: TraceFlags.NONE,
+  };
+
   constructor(readonly moduleName: string, readonly version: string) {
     super(`@opentelemetry/plugin-${moduleName}`, VERSION);
     // For now component is equal to moduleName but it can change in the future.
@@ -295,10 +308,23 @@ export class HttpPlugin extends BasePlugin<Http> {
       };
 
       return context.with(propagation.extract(headers), () => {
-        const span = plugin._startHttpSpan(
-          `${method} ${pathname}`,
-          spanOptions
-        );
+        let span: Span = new NoopSpan();
+        const hasParent = plugin._tracer.getCurrentSpan() !== undefined;
+        /*
+         * If a parent is required but not present, we use a `NoRecordingSpan` to still
+         * propagate context without recording it.
+         */
+        if (
+          plugin._config.requireParentforIncomingSpans === true &&
+          hasParent === false
+        ) {
+          const spanContext =
+            getExtractedSpanContext(context.active()) ??
+            plugin._emptySpanContext;
+          span = new NoRecordingSpan(spanContext);
+        } else {
+          span = plugin._startHttpSpan(`${method} ${pathname}`, spanOptions);
+        }
 
         return plugin._tracer.withSpan(span, () => {
           context.bind(request);
@@ -396,8 +422,22 @@ export class HttpPlugin extends BasePlugin<Http> {
       const spanOptions: SpanOptions = {
         kind: SpanKind.CLIENT,
       };
-
-      const span = plugin._startHttpSpan(operationName, spanOptions);
+      const hasParent = plugin._tracer.getCurrentSpan() !== undefined;
+      let span: Span = new NoopSpan();
+      /*
+       * If a parent is required but not present, we use a `NoRecordingSpan` to still
+       * propagate context without recording it.
+       */
+      if (
+        plugin._config.requireParentforOutgoingSpans === true &&
+        hasParent === false
+      ) {
+        const spanContext =
+          getExtractedSpanContext(context.active()) ?? plugin._emptySpanContext;
+        span = new NoRecordingSpan(spanContext);
+      } else {
+        span = plugin._startHttpSpan(operationName, spanOptions);
+      }
 
       return plugin._tracer.withSpan(span, () => {
         if (!optionsParsed.headers) optionsParsed.headers = {};

diff --git a/packages/opentelemetry-plugin-http/src/types.ts b/packages/opentelemetry-plugin-http/src/types.ts
@@ -69,6 +69,10 @@ export interface HttpPluginConfig extends PluginConfig {
   applyCustomAttributesOnSpan?: HttpCustomAttributeFunction;
   /** The primary server name of the matched virtual host. */
   serverName?: string;
+  /** Require parent to create span for outgoing requests */
+  requireParentforOutgoingSpans?: boolean;
+  /** Require parent to create span for incoming requests */
+  requireParentforIncomingSpans?: boolean;
 }
 
 export interface Err extends Error {

diff --git a/packages/opentelemetry-plugin-http/test/functionals/http-enable.test.ts b/packages/opentelemetry-plugin-http/test/functionals/http-enable.test.ts
@@ -696,5 +696,84 @@ describe('HttpPlugin', () => {
         req.end();
       });
     });
+
+    describe('with require parent span', () => {
+      beforeEach(() => {
+        memoryExporter.reset();
+        plugin.enable(http, provider, provider.logger, {});
+        server = http.createServer((request, response) => {
+          response.end('Test Server Response');
+        });
+        server.listen(serverPort);
+      });
+
+      afterEach(() => {
+        server.close();
+        plugin.disable();
+      });
+
+      it(`should not trace without parent with options enabled (both client & server)`, async () => {
+        plugin.disable();
+        const config: HttpPluginConfig = {
+          requireParentforIncomingSpans: true,
+          requireParentforOutgoingSpans: true,
+        };
+        plugin.enable(http, provider, provider.logger, config);
+        const testPath = `/test/test`;
+        await httpRequest.get(
+          `${protocol}://${hostname}:${serverPort}${testPath}`
+        );
+        const spans = memoryExporter.getFinishedSpans();
+        assert.strictEqual(spans.length, 0);
+      });
+
+      it(`should not trace without parent with options enabled (client only)`, async () => {
+        plugin.disable();
+        const config: HttpPluginConfig = {
+          requireParentforOutgoingSpans: true,
+        };
+        plugin.enable(http, provider, provider.logger, config);
+        const testPath = `/test/test`;
+        const result = await httpRequest.get(
+          `${protocol}://${hostname}:${serverPort}${testPath}`
+        );
+        assert(
+          result.reqHeaders[DummyPropagation.TRACE_CONTEXT_KEY] !== undefined
+        );
+        assert(
+          result.reqHeaders[DummyPropagation.SPAN_CONTEXT_KEY] !== undefined
+        );
+        const spans = memoryExporter.getFinishedSpans();
+        assert.strictEqual(spans.length, 1);
+        assert.strictEqual(
+          spans.every(span => span.kind === SpanKind.SERVER),
+          true
+        );
+      });
+
+      it(`should not trace without parent with options enabled (server only)`, async () => {
+        plugin.disable();
+        const config: HttpPluginConfig = {
+          requireParentforIncomingSpans: true,
+        };
+        plugin.enable(http, provider, provider.logger, config);
+        const testPath = `/test/test`;
+        const result = await httpRequest.get(
+          `${protocol}://${hostname}:${serverPort}${testPath}`
+        );
+        assert(
+          result.reqHeaders[DummyPropagation.TRACE_CONTEXT_KEY] !== undefined
+        );
+        assert(
+          result.reqHeaders[DummyPropagation.SPAN_CONTEXT_KEY] !== undefined
+        );
+        const spans = memoryExporter.getFinishedSpans();
+        assert.strictEqual(spans.length, 1);
+        assert.strictEqual(
+          spans.every(span => span.kind === SpanKind.CLIENT),
+          true
+        );
+      });
+    });
   });
 });