Merge pull request #3 from zazuko/next-otel

OpenTelemetry tracing

packages/http/lib/fetch.js

@@ -1,10 +1,21 @@
+import { SpanStatusCode } from '@opentelemetry/api'
 import toReadable from 'duplex-to/readable.js'
 import nodeFetch from 'node-fetch'
+import tracer from './tracer.js'
 
 async function fetch ({ method = 'GET', url, ...options } = {}) {
-  const response = await nodeFetch(url, { method, ...options })
+  return await tracer.startActiveSpan('fetch', async span => {
+    try {
+      const response = await nodeFetch(url, { method, ...options })
 
-  return toReadable(response.body)
+      return toReadable(response.body)
+    } catch (e) {
+      span.recordException(e)
+      span.setStatus({ code: SpanStatusCode.ERROR, message: e.message })
+    } finally {
+      span.end()
+    }
+  })
 }
 
 export default fetch

packages/http/lib/tracer.js

@@ -0,0 +1,6 @@
+import { trace } from '@opentelemetry/api'
+
+// TODO: set library version here
+const tracer = trace.getTracer('barnard59-http')
+
+export default tracer

packages/http/lib/writableFetch.js

@@ -1,20 +1,23 @@
 import duplexify from 'duplexify'
 import nodeFetch from 'node-fetch'
 import { PassThrough } from 'readable-stream'
+import tracer from './tracer.js'
 
 async function fetch ({ method = 'POST', url, ...options } = {}) {
   const inputStream = new PassThrough()
   const outputStream = new PassThrough()
 
-  setTimeout(async () => {
+  tracer.startActiveSpan('writableFetch', span => setTimeout(async () => {
     try {
       const response = await nodeFetch(url, { method, body: inputStream, ...options })
 
       response.body.pipe(outputStream)
     } catch (err) {
       outputStream.emit('error', err)
+    } finally {
+      span.end()
     }
-  }, 0)
+  }, 0))
 
   return duplexify(inputStream, outputStream)
 }

packages/http/package.json

@@ -20,6 +20,7 @@
   },
   "homepage": "https://github.com/zazuko/barnard59-http",
   "dependencies": {
+    "@opentelemetry/api": "^1.0.1",
     "duplex-to": "^1.0.1",
     "duplexify": "^4.0.0",
     "node-fetch": "^2.6.1",