Initial commit

pkg/demogrpc/demo.go

@@ -0,0 +1,86 @@
+package demogrpc
+
+import (
+	"context"
+	"fmt"
+
+	"github.com/go-resty/resty/v2"
+	"github.com/rs/zerolog"
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/trace"
+
+	grpccodes "google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
+
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/otel"
+
+	pb "gitea.libretechconsulting.com/rmcguire/go-server-with-otel/api/demo/app/v1alpha1"
+	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/config"
+)
+
+const (
+	defaultFactType = config.TypeRandom
+	factsBaseURI    = "https://uselessfacts.jsph.pl/api/v2/facts"
+)
+
+type DemoGRPCServer struct {
+	tracer trace.Tracer
+	ctx    context.Context
+	cfg    *config.DemoConfig
+	client *resty.Client
+	pb.UnimplementedDemoAppServiceServer
+}
+
+func NewDemoGRPCServer(ctx context.Context, cfg *config.DemoConfig) *DemoGRPCServer {
+	if cfg.Opts == nil {
+		cfg.Opts = &config.DemoOpts{}
+	}
+
+	if cfg.Opts.FactType == "" {
+		cfg.Opts.FactType = config.TypeRandom
+	}
+
+	return &DemoGRPCServer{
+		ctx:    ctx,
+		cfg:    cfg,
+		tracer: otel.GetTracer(ctx, "demoGRPCServer"),
+		client: resty.New().SetBaseURL(factsBaseURI),
+	}
+}
+
+func (d *DemoGRPCServer) GetDemo(ctx context.Context, req *pb.GetDemoRequest) (
+	*pb.GetDemoResponse, error,
+) {
+	ctx, span := d.tracer.Start(ctx, "getDemo", trace.WithAttributes(
+		attribute.String("language", req.GetLanguage()),
+	))
+	defer span.End()
+
+	r := d.client.R().SetContext(ctx)
+
+	if req.GetLanguage() != "" {
+		r = r.SetQueryParam("language", req.GetLanguage())
+	}
+
+	fact := new(RandomFact)
+	r.SetResult(fact)
+
+	resp, err := r.Get(fmt.Sprintf("/%s", d.cfg.Opts.FactType))
+	if err != nil {
+		span.SetStatus(codes.Error, err.Error())
+		span.RecordError(err)
+
+		zerolog.Ctx(d.ctx).Err(err).Send()
+
+		return nil, status.Errorf(grpccodes.Unknown, "%s: %s",
+			err.Error(), string(resp.Body()))
+	}
+
+	span.SetAttributes(attribute.String("fact", fact.Text))
+	span.SetStatus(codes.Ok, "")
+
+	zerolog.Ctx(d.ctx).Debug().Str("fact", fact.Text).Msg("retrieved fact")
+
+	return fact.FactToProto(), nil
+}