Add console support for logfire-cf-workers

Fixes #52

Author: petyosi

.changeset/soft-items-sort.md

@@ -0,0 +1,5 @@
+---
+"@pydantic/logfire-cf-workers": minor
+---
+
+Support console logging of spans for CF workers

examples/cf-worker/src/index.ts

@@ -15,7 +15,7 @@ import { instrument } from '@pydantic/logfire-cf-workers';
 
 const handler = {
 	async fetch(): Promise<Response> {
-		logfire.info('info span from inside the worker body');
+		logfire.info('span from inside the worker body', { foo: 'bar' });
 		return new Response('Hello World!');
 	},
 } satisfies ExportedHandler;
@@ -26,4 +26,5 @@ export default instrument(handler, {
 		namespace: '',
 		version: '1.0.0',
 	},
+	console: true,
 });

package-lock.json

@@ -50,7 +50,7 @@
   },
   "dependencies": {
     "@pydantic/logfire-api": "*",
-    "@pydantic/otel-cf-workers": "^1.0.0-rc.53"
+    "@pydantic/otel-cf-workers": "^1.0.0-rc.54"
   },
   "devDependencies": {
     "@cloudflare/workers-types": "4.20250311.0",

packages/logfire-cf-workers/package.json

@@ -0,0 +1,73 @@
+import { ExportResult, ExportResultCode, hrTimeToMicroseconds } from '@opentelemetry/core'
+import { ReadableSpan, SpanExporter } from '@opentelemetry/sdk-trace-base'
+
+const LevelLabels = {
+  1: 'trace',
+  5: 'debug',
+  9: 'info',
+  10: 'notice',
+  13: 'warning',
+  17: 'error',
+  21: 'fatal',
+} as const
+
+/**
+ * Prints spans in the terminal, using the respective color sequences.
+ */
+export class LogfireCloudflareConsoleSpanExporter implements SpanExporter {
+  export(spans: ReadableSpan[], resultCallback: (result: ExportResult) => void): void {
+    this.sendSpans(spans, resultCallback)
+  }
+
+  forceFlush(): Promise<void> {
+    return Promise.resolve()
+  }
+  shutdown(): Promise<void> {
+    this.sendSpans([])
+    return this.forceFlush()
+  }
+
+  /**
+   * converts span info into more readable format
+   * @param span
+   */
+  private exportInfo(span: ReadableSpan) {
+    return {
+      attributes: span.attributes,
+      duration: hrTimeToMicroseconds(span.duration),
+      events: span.events,
+      id: span.spanContext().spanId,
+      instrumentationScope: span.instrumentationScope,
+      kind: span.kind,
+      links: span.links,
+      name: span.name,
+      parentSpanContext: span.parentSpanContext,
+      resource: {
+        attributes: span.resource.attributes,
+      },
+      status: span.status,
+      timestamp: hrTimeToMicroseconds(span.startTime),
+      traceId: span.spanContext().traceId,
+      traceState: span.spanContext().traceState?.serialize(),
+    }
+  }
+
+  private sendSpans(spans: ReadableSpan[], done?: (result: ExportResult) => void): void {
+    for (const span of spans) {
+      // eslint-disable-next-line @typescript-eslint/no-unnecessary-condition
+      const type = LevelLabels[span.attributes['logfire.level_num'] as keyof typeof LevelLabels] ?? 'info'
+
+      const { attributes, name, ...rest } = this.exportInfo(span)
+      console.log(`Logfire: ${type} >> ${name}`)
+      console.log('Attributes:')
+      console.log(JSON.stringify(attributes, null, 2))
+      console.log('---')
+      console.log('Span details:')
+      console.log(JSON.stringify(rest, null, 2))
+      console.log('---')
+    }
+    if (done) {
+      done({ code: ExportResultCode.SUCCESS })
+    }
+  }
+}

packages/logfire-cf-workers/src/LogfireCloudflareConsoleSpanExporter.ts

@@ -1,9 +1,9 @@
-import type { ReadableSpan } from '@opentelemetry/sdk-trace-base'
-
-import { resolveBaseUrl, serializeAttributes, ULIDGenerator } from '@pydantic/logfire-api'
+import { type ReadableSpan, SimpleSpanProcessor } from '@opentelemetry/sdk-trace-base'
 import * as logfireApi from '@pydantic/logfire-api'
+import { resolveBaseUrl, serializeAttributes, ULIDGenerator } from '@pydantic/logfire-api'
 import { instrument as baseInstrument, TraceConfig } from '@pydantic/otel-cf-workers'
 
+import { LogfireCloudflareConsoleSpanExporter } from './LogfireCloudflareConsoleSpanExporter'
 import { TailWorkerExporter } from './TailWorkerExporter'
 export * from './exportTailEventsToLogfire'
 
@@ -16,6 +16,10 @@ type ConfigOptionsBase = Pick<
 
 export interface InProcessConfigOptions extends ConfigOptionsBase {
   baseUrl?: string
+  /**
+   * Whether to log the spans to the console in addition to sending them to the Logfire API.
+   */
+  console?: boolean
   /**
    * Options for scrubbing sensitive data. Set to False to disable.
    */
@@ -32,15 +36,18 @@ function getInProcessConfig(config: InProcessConfigOptions): (env: Env) => Trace
     const baseUrl = resolveBaseUrl(env, config.baseUrl, token)
     const resolvedEnvironment = config.environment ?? envDeploymentEnvironment
 
+    const additionalSpanProcessors = config.console ? [new SimpleSpanProcessor(new LogfireCloudflareConsoleSpanExporter())] : []
+
     return Object.assign({}, config, {
+      additionalSpanProcessors,
       environment: resolvedEnvironment,
       exporter: {
         headers: { Authorization: token },
         url: `${baseUrl}/v1/traces`,
       },
       idGenerator: new ULIDGenerator(),
       postProcessor: (spans: ReadableSpan[]) => postProcessAttributes(spans),
-    })
+    }) satisfies TraceConfig
   }
 }