[paymentservice] add basic metrics support

CHANGELOG.md

@@ -138,3 +138,5 @@ significant modifications will be credited to OpenTelemetry Authors.
 ([#569](https:/open-telemetry/opentelemetry-demo/pull/569))
 * Optimize GitHub Builds and fix broken emulation of featureflag
 ([#536](https:/open-telemetry/opentelemetry-demo/pull/536))
+* Add basic metrics support for payment service
+([#583](https:/open-telemetry/opentelemetry-demo/pull/583))

docker-compose.yml

@@ -286,6 +286,8 @@ services:
  environment:
  - PAYMENT_SERVICE_PORT
  - OTEL_EXPORTER_OTLP_TRACES_ENDPOINT
+ - OTEL_EXPORTER_OTLP_METRICS_ENDPOINT
+ - OTEL_EXPORTER_OTLP_METRICS_TEMPORALITY_PREFERENCE
  - OTEL_SERVICE_NAME=paymentservice
  depends_on:
  - otelcol

src/paymentservice/Dockerfile

@@ -33,4 +33,4 @@ COPY ./src/paymentservice/ ./
 COPY ./pb/demo.proto ./
 
 EXPOSE ${PAYMENT_SERVICE_PORT}
-ENTRYPOINT [ "node", "--require", "./tracing.js", "./index.js" ]
+ENTRYPOINT [ "npm", "run", "start" ]

src/paymentservice/charge.js

@@ -13,16 +13,20 @@
 // limitations under the License.
 
 const {context, propagation, trace} = require('@opentelemetry/api');
+const { metrics } = require('@opentelemetry/api-metrics');
 const cardValidator = require('simple-card-validator');
 const { v4: uuidv4 } = require('uuid');
 
 const logger = require('./logger');
 const tracer = trace.getTracer('paymentservice');
+const meter = metrics.getMeter('paymentservice');
+const transactionsCounter = meter.createCounter('app.payment.transactions')
 
 module.exports.charge = request => {
  const span = tracer.startSpan('charge');
 
- const { creditCardNumber: number,
+ const {
+ creditCardNumber: number,
  creditCardExpirationYear: year,
  creditCardExpirationMonth: month
  } = request.creditCard;
@@ -32,7 +36,7 @@ module.exports.charge = request => {
  const transactionId = uuidv4();
 
  const card = cardValidator(number);
- const {card_type: cardType, valid } = card.getCardDetails();
+ const { card_type: cardType, valid } = card.getCardDetails();
 
  span.setAttributes({
  'app.payment.card_type': cardType,
@@ -53,7 +57,7 @@ module.exports.charge = request => {
 
  // check baggage for synthetic_request=true, and add charged attribute accordingly
  const baggage = propagation.getBaggage(context.active());
- if (baggage && baggage.getEntry("synthetic_request") && baggage.getEntry("synthetic_request").value == "true") {
+ if (baggage && baggage.getEntry("synthetic_request") && baggage.getEntry("synthetic_request").value === "true") {
  span.setAttribute('app.payment.charged', false);
  } else {
  span.setAttribute('app.payment.charged', true);
@@ -63,6 +67,6 @@ module.exports.charge = request => {
 
  const { units, nanos, currencyCode } = request.amount;
  logger.info({transactionId, cardType, lastFourDigits, amount: { units, nanos, currencyCode }}, "Transaction complete.");
-
+ transactionsCounter.add(1, {"app.payment.currency": currencyCode})
  return { transactionId }
 }

src/paymentservice/opentelemetry.js

@@ -0,0 +1,15 @@
+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 { PeriodicExportingMetricReader } = require('@opentelemetry/sdk-metrics');
+
+const sdk = new opentelemetry.NodeSDK({
+ traceExporter: new OTLPTraceExporter(),
+ instrumentations: [ getNodeAutoInstrumentations() ],
+ metricReader: new PeriodicExportingMetricReader({
+ exporter: new OTLPMetricExporter()
+ }),
+})
+
+sdk.start().then(() => require("./index"));