Send data to local p8s (#9)

Signed-off-by: Pavol Loffay <p.loffay@gmail.com>

03-app-instrumentation.md

@@ -123,7 +123,7 @@ Now replace the `ConsoleSpanExporter` with an `OTLPTraceExporter` as outlined in
 
 The metrics can be reported to the Prometheus server running locally:
 ```bash
-docker run --rm -it -p 9090:9090 -p 4317:4317 --name=p8s -v ./app/prometheus-docker.yaml:/tmp/prometheus-docker.yaml:z prom/prometheus --config.file=/tmp/prometheus-docker.yaml --enable-feature=otlp-write-receiver
+docker run --rm -it -p 9090:9090 --name=p8s -v ./app/prometheus-docker.yaml:/tmp/prometheus-docker.yaml:z prom/prometheus --config.file=/tmp/prometheus-docker.yaml --enable-feature=otlp-write-receiver
 ```
 
 Alternatively, you can run the OpenTelemetry collector locally with debug exporter:

app/frontend/index.js

@@ -6,6 +6,7 @@ const http = require("http");
 const app = require("express")();
 const pino = require('pino-http')()
 
+// not included by default
 //var otelsdkinit = require('./instrument.js');
 
 app.use(pino)

app/frontend/instrument.js

@@ -10,7 +10,8 @@
 const opentelemetry = require("@opentelemetry/sdk-node");
 const { getNodeAutoInstrumentations } = require("@opentelemetry/auto-instrumentations-node");
 const { OTLPTraceExporter } = require("@opentelemetry/exporter-trace-otlp-grpc");
-const { OTLPMetricExporter } = require('@opentelemetry/exporter-metrics-otlp-grpc');
+const otlpGrpc = require('@opentelemetry/exporter-metrics-otlp-grpc');
+const otlpHttp = require('@opentelemetry/exporter-metrics-otlp-http');
 
 const { PeriodicExportingMetricReader, MeterProvider, ConsoleMetricExporter } = require('@opentelemetry/sdk-metrics')
 
@@ -25,8 +26,13 @@ const sdk = new opentelemetry.NodeSDK({
     }),
     traceExporter: new OTLPTraceExporter(),
     metricReader: new PeriodicExportingMetricReader({
-        exporter: new OTLPMetricExporter(),
-//        exporter: new ConsoleMetricExporter()
+//         exporter: new ConsoleMetricExporter()
+        // by default send data to OTLP via gRPC
+        exporter: new otlpGrpc.OTLPMetricExporter(),
+        // for sending data to Prometheus
+//        exporter: new otlpHttp.OTLPMetricExporter({
+//          url: "http://localhost:9090/api/v1/otlp/v1/metrics", // p8s expose /v1/metrics under /api/v1/otlp
+//        }),
     }),
     instrumentations: [getNodeAutoInstrumentations()]
 });

app/frontend/package.json

@@ -3,6 +3,7 @@
     "@opentelemetry/api": "^1.4.1",
     "@opentelemetry/auto-instrumentations-node": "^0.39.4",
     "@opentelemetry/exporter-metrics-otlp-grpc": "^0.44.0",
+    "@opentelemetry/exporter-metrics-otlp-http": "^0.43.0",
     "@opentelemetry/exporter-prometheus": "^0.44.0",
     "@opentelemetry/exporter-trace-otlp-grpc": "^0.44.0",
     "@opentelemetry/sdk-metrics": "^1.17.1",

app/prometheus-docker.yaml

@@ -10,6 +10,6 @@ rule_files:
 # - "first_rules.yml"
 # - "second_rules.yml"
 scrape_configs:
-  - job_name: "prometheus"
-    static_configs:
-      - targets: ["localhost:9090"]
+#  - job_name: "prometheus"
+#    static_configs:
+#      - targets: ["localhost:9090"]