dkdkv/Go-codegen-test

Create API by OpenAPI spec

example

Example for server and client with graceful shutdown and open telemetry exporters for prometheus and jaeger.

• Force go.mod to have ogen in tools.go
• Generate code by gen.go
• Metrics boilerplate in internal/app

Server

Environmental variables

Name	Value	Description
OTEL_SERVICE_NAME	api	OpenTelemetry service name
OTEL_RESOURCE_ATTRIBUTES	service.namespace=example	Additional OpenTelemetry resource attributes
OTEL_EXPORTER_JAEGER_AGENT_HOST	localhost	Jaeger host to use
OTEL_EXPORTER_JAEGER_AGENT_PORT	6831	Jaeger port to use (UDP)

Run server

$ OTEL_SERVICE_NAME=api OTEL_RESOURCE_ATTRIBUTES="service.namespace=example" go run ./cmd/api-server
{"level":"info","ts":1658763761.0027707,"caller":"api-server/main.go:27","msg":"Initializing","http.addr":"127.0.0.1:8080","metrics.addr":"127.0.0.1:9090"}
{"level":"info","ts":1658763761.0033038,"caller":"app/metrics.go:224","msg":"Metrics initialized","otel.resource":"service.name=api,service.namespace=example,telemetry.sdk.language=go,telemetry.sdk.name=opentelemetry,telemetry.sdk.version=1.8.0","http.addr":"127.0.0.1:9090"}

Check metrics

$ curl localhost:9090
Service is up and running.

Resource:
  service.name                     api
  service.namespace                example
  telemetry.sdk.language           go
  telemetry.sdk.name               opentelemetry
  telemetry.sdk.version            1.8.0

Available debug endpoints:
/metrics             - prometheus metrics
/debug/pprof         - exported pprof

Client

$ go run ./cmd/api-client --id 1337
pet: {
  "id": 1337,
  "name": "Pet 1337",
  "status": "available"
}