[Feature] otel context injection (#133)

* Add `_addOpentelemetryContext()`

* update dependencies

* Add unit tests

* Update dependencies

* Update log

* Add `addOtelContext` configuration option

* docs

* refactor tests

Author: yotamloe

README.md

@@ -54,6 +54,7 @@ logger.log(obj);
 * **compress** - If true the the logs are compressed in gzip format. Default: `false`
 * **internalLogger** - set internal logger that supports the function log. Default: console.
 * **extraFields** - Adds your own custom fields to each log. Add in JSON Format, for example: `extraFields : { field_1: "val_1", field_2: "val_2" , ... }`.
+* **addOtelContext** - Add `trace_id`, `span_id`, `service_name` fields to logs when opentelemetry context is available.  Default: `true`
 
 
 ## Using UDP
@@ -99,6 +100,17 @@ logger.log('This is a log message');
     }
 ```
 
+## Add opentelemetry context
+If you're sending traces with OpenTelemetry instrumentation (auto or manual), you can correlate your logs with the trace context. That way, your logs will have traces data in it, such as service name, span id and trace id (version >= `2.2.0`). This feature is enabled by default, To disable it, set the `AddOtelContext` param in your handler configuration to `false`, like in this example:
+
+```javascript
+var logger = require('logzio-nodejs').createLogger({
+  token: 'token',
+  type: 'no-otel-context',
+  addOtelContext: false
+});
+```
+
 ## Build and test locally
 1. Clone the repository:
   ```bash
@@ -112,6 +124,10 @@ logger.log('This is a log message');
   ```
 
 ## Update log
+**2.2.0**
+- Add `addOtelContext` configuration option:
+  - `trace_id`, `span_id`, `service_name` fields to logs when opentelemetry context is available.
+
 **2.1.8**
 - Make `User-Agent` not optional and add the version to it.
 

lib/logzio-nodejs.js

@@ -4,7 +4,7 @@ const assign = require('lodash.assign');
 const dgram = require('dgram');
 const zlib = require('zlib');
 const axiosInstance = require('./axiosInstance');
-
+const { trace, context } = require('@opentelemetry/api');
 
 const nanoSecDigits = 9;
 
@@ -53,6 +53,7 @@ class LogzioLogger {
         protocol = 'http',
         port,
         timeout,
+        addOtelContext = true,
         sleepUntilNextRetry = 2 * 1000,
         callback = this._defaultCallback,
         extraFields = {},
@@ -103,11 +104,13 @@ class LogzioLogger {
         this.timeout = timeout;
 
         // build the url for logging
-
         this.messages = [];
         this.bulkId = 1;
         this.extraFields = extraFields;
         this.typeOfIP = 'IPv4';
+
+        // OpenTelemetry context
+        this.addOtelContext = addOtelContext
     }
 
     _setProtocol(port) {
@@ -231,31 +234,47 @@ class LogzioLogger {
             }
         }
     }
-
+    /**
+      * Attach OpenTelemetry context to the log record.
+      * @param msg - The message (Object) to append the OpenTelemetry context to.
+      * @private
+      */
+    _addOpentelemetryContext(msg) {
+      if (!this.addOtelContext) {
+        return;
+      }
+      let span = trace.getSpan(context.active());
+      if (span) {
+        msg.trace_id = span.spanContext().traceId;
+        msg.span_id = span.spanContext().spanId;
+        msg.service_name = span.resource._attributes['service.name'];
+      }
+    }
     log(msg, obj) {
-        if (this.closed === true) {
-            throw new Error('Logging into a logger that has been closed!');
-        }
-        if (![null, undefined].includes(obj)) {
-            msg += JSON.stringify(obj);
-        }
-        if (typeof msg === 'string') {
-            msg = {
-                message: msg,
-            };
-        }
-        this._addSourceIP(msg);
-        msg = assign(msg, this.extraFields);
-        if (!msg.type) {
-            msg.type = this.type;
-        }
-        this._addTimestamp(msg);
-
-        this.messages.push(msg);
-        if (this.messages.length >= this.bufferSize) {
-            this._debug('Buffer is full - sending bulk');
-            this._popMsgsAndSend();
-        }
+      if (this.closed === true) {
+        throw new Error('Logging into a logger that has been closed!');
+      }
+      if (![null, undefined].includes(obj)) {
+        msg += JSON.stringify(obj);
+      }
+      if (typeof msg === 'string') {
+        msg = { message: msg };
+      }
+  
+      this._addSourceIP(msg);
+      msg = assign(msg, this.extraFields);
+      if (!msg.type) {
+        msg.type = this.type;
+      }
+      this._addTimestamp(msg);
+      this._addOpentelemetryContext(msg);
+  
+  
+      this.messages.push(msg);
+      if (this.messages.length >= this.bufferSize) {
+        this._debug('Buffer is full - sending bulk');
+        this._popMsgsAndSend();
+      }
     }
 
     _popMsgsAndSend() {