updated nodejs instrumentation doc to disable fs instrumentation

ref: open-telemetry/opentelemetry-js-contrib#1344

docs/instrumentation/nodeJS.md

@@ -9,34 +9,68 @@ slug: /instrumentation/nodejs
 1. Install dependencies
 
    ```shell
-   npm install --save @opentelemetry/auto-instrumentations-node@^0.38.0
+   npm install --save @opentelemetry/auto-instrumentations-node
    ```
 
-1. Add the following environment variables:
-
-   ```bash
-   OTEL_METRICS_EXPORTER=none
-   OTEL_TRACES_EXPORTER=otlp
-   OTEL_EXPORTER_OTLP_TRACES_PROTOCOL=grpc
-   OTEL_EXPORTER_OTLP_COMPRESSION=gzip
-   OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=http://<ip_address_of_cubeapm_server>:4317
-   OTEL_SERVICE_NAME=<app_name>
-   NODE_OPTIONS="--require @opentelemetry/auto-instrumentations-node/register"
+1. Create a file `tracing.js` in your project directory, with the following content:
+
+   ```javascript title="tracing.js"
+   "use strict";
+   const process = require("process");
+   const {
+     diag,
+     DiagConsoleLogger,
+     DiagLogLevel,
+   } = require("@opentelemetry/api");
+   const opentelemetry = require("@opentelemetry/sdk-node");
+   const {
+     getNodeAutoInstrumentations,
+   } = require("@opentelemetry/auto-instrumentations-node");
+   const {
+     OTLPTraceExporter,
+   } = require("@opentelemetry/exporter-trace-otlp-grpc");
+
+   if (process.env.OTEL_LOG_LEVEL === "debug") {
+     diag.setLogger(new DiagConsoleLogger(), DiagLogLevel.INFO);
+   }
+
+   const exporterOptions = {
+     // concurrencyLimit: 1,
+   };
+   const traceExporter =
+     process.env.OTEL_LOG_LEVEL === "debug"
+       ? new opentelemetry.tracing.ConsoleSpanExporter()
+       : new OTLPTraceExporter(exporterOptions);
+
+   const sdk = new opentelemetry.NodeSDK({
+     traceExporter,
+     instrumentations: getNodeAutoInstrumentations({
+       "@opentelemetry/instrumentation-fs": {
+         enabled: false,
+       },
+     }),
+   });
+
+   // initialize the SDK and register with the OpenTelemetry API
+   // this enables the API to record telemetry
+   sdk.start();
    ```
 
-   For example, if the run command is `node index.js`, then change it to:
+1. Modify the application run command as follows:
 
-   ```bash
+   ```shell
    OTEL_METRICS_EXPORTER=none \
-   OTEL_TRACES_EXPORTER=otlp \
-   OTEL_EXPORTER_OTLP_TRACES_PROTOCOL=grpc \
    OTEL_EXPORTER_OTLP_COMPRESSION=gzip \
    OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=http://<ip_address_of_cubeapm_server>:4317 \
    OTEL_SERVICE_NAME=<app_name> \
-   NODE_OPTIONS="--require @opentelemetry/auto-instrumentations-node/register" \
-   node index.js
+   NODE_OPTIONS="--require ./tracing.js" \
+   node app.js
    ```
 
+### Sample App
+
+A working example with multiple instrumentations is available at https://github.com/cubeapm/sample_app_nodejs_express
+
 ## Capture Exception StackTraces (optional)
 
 CubeAPM shows stacktraces for any exceptions that occur in your application. However, if you are using the Express framework, you need to add the following code to your Express error handler to capture the stacktraces: