This is an example for jaeger tracing in go for micro services. It assumes Jaeger has been installed already (at kubernetes, or no-k8s env), and you are already familiar with Opentracing.

You might want to tweak the variables defined at pkg/constants, depending on your installment.

This repository shows tracing for restful request, grpc server request, and custom function(such as database connection/request).

Key points:

• Two services: cart, product. Service product has set up grpc server and rest server. Service cart only sets up rest server. Service cart will send grpc request to service product grpc server.
• To enable grpc server tracing, use grpc middleware.
• Start the root span at (p *provider) Middleware(). This middleware will create a root span for every restful request.
• Pass the propagating span relation using opentracing.StartSpanFromContext(). So we will see a request span to service product grpc server has a parent request span to service cart, using the context.Context.
• Create custom span like span, ctx := tracing.StartSpan(c, "cart item create"). See service.cart/main.go - SaveCart().
• Use mock tracing provider for test.

You might want to check the full example at repository micro ecommerce.

See the demo result like

Jaeger UI

Test Post command

curl --header "Content-Type: application/json" \
  --request POST \
  --data '{"sku_id":"12","quantity":1}' \
  http://127.0.0.1:1325/cart

Proto Update

cd service.product/internal

protoc --go_out=. --go_opt=paths=source_relative \
    --go-grpc_out=. --go-grpc_opt=paths=source_relative \
    proto/product.proto