146 lines
3.7 KiB
Go
146 lines
3.7 KiB
Go
// This template contains a simple
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// app with OTEL bootstrap that will create an
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// HTTP server configured by environment that exports
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// spans and metrics to an OTEL collector if configured
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// to do so. Will also stand up a prometheus metrics
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// endpoint.
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//
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// Configuration and logger stored in context
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// Reference implementation of the provided packages
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package main
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import (
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"context"
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"flag"
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"fmt"
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"os"
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"os/signal"
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"sync"
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"syscall"
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"time"
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"github.com/rs/zerolog"
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"go.opentelemetry.io/otel/attribute"
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"go.opentelemetry.io/otel/codes"
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"go.opentelemetry.io/otel/trace"
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"gitea.libretechconsulting.com/rmcguire/go-app/pkg/app"
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"gitea.libretechconsulting.com/rmcguire/go-app/pkg/otel"
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"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/config"
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"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/demo"
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"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/service"
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)
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const (
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terminationGracePeriod = 30 * time.Second
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appName = "demo-app"
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)
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var (
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// TODO: Register your service.AppService implementers here
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// This should be the only change necessary here
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// NOTE: At least one service needs to add a dial option
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// for transport credentials, otherwise you will have to do it here
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appServices = []service.AppService{
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&demo.DemoService{},
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}
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flagSchema bool
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)
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func main() {
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ctx, cncl := signal.NotifyContext(context.Background(), os.Interrupt, syscall.SIGTERM, syscall.SIGQUIT)
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defer cncl()
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// Load configuration and setup logging. The go-app framework
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// will handle loading config and environment into our demo
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// app config struct which embeds app.AooConfig
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ctx, serviceConfig := app.MustLoadConfigInto(ctx, &config.ServiceConfig{})
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// Print schema if that's all we have to do
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if flagSchema {
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printSchema()
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os.Exit(0)
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}
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// Prepare app
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app := &app.App{
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AppContext: ctx,
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}
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app.InitOTEL()
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tracer := otel.GetTracer(ctx, appName)
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ctx, span := tracer.Start(ctx, appName+".startup", trace.WithAttributes(
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attribute.Int("appServices", len(appServices)),
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))
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log := zerolog.Ctx(ctx)
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log.Debug().Any("mergedConfig", serviceConfig).Msg("App configuration prepared")
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// Prepare services
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var err error
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sdFuncs := make([]service.ShutdownFunc, len(appServices))
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for i, svc := range appServices {
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sdFuncs[i], err = svc.Init(ctx, serviceConfig)
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if err != nil {
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span.RecordError(err)
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span.SetStatus(codes.Error, err.Error())
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log.Fatal().Err(err).Send()
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}
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}
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span.AddEvent("app services initialized")
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// Merge all service implementations and add to app
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grpcSvcs, httpSvcs := service.MergeServices(ctx, appServices...)
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app.GRPC = grpcSvcs
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app.HTTP = httpSvcs
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span.SetAttributes(
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attribute.Int("grpcServices", len(app.GRPC.Services)),
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attribute.Int("httpServices", len(app.HTTP.Funcs)+len(app.HTTP.Handlers)),
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)
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// Launch app
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app.MustRun()
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span.AddEvent("app started")
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span.SetStatus(codes.Ok, "")
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span.End()
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// Wait for app to complete and then perform internal shutdown
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<-app.Done()
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log.Info().Int("numServices", len(appServices)).Msg("shutting down app services")
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sdCtx, cncl := context.WithTimeout(context.Background(), terminationGracePeriod)
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defer cncl()
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// Call registered shutdown funcs from all services
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var sdWg sync.WaitGroup
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for _, sdFunc := range sdFuncs {
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sdWg.Add(1)
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go func() {
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defer sdWg.Done()
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svcName, err := sdFunc(sdCtx)
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log.Err(err).Str("service", svcName).Msg("terminated")
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}()
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}
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sdWg.Wait()
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}
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// flag.Parse will be called by go-app
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func init() {
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flag.BoolVar(&flagSchema, "schema", false, "generate json schema and exit")
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}
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func printSchema() {
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bytes, err := app.CustomSchema(&config.ServiceConfig{})
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if err != nil {
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panic(err)
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}
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fmt.Println(string(bytes))
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os.Exit(0)
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}
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