improve shutdown and app service boilerplate

pkg/demo/demo.go

@@ -0,0 +1,54 @@
+// Package demo provides a reference implementation
+// of service.AppService. It packages out the GRPC and HTTP
+// functionality, for the sake of structure.
+package demo
+
+import (
+	"context"
+
+	optsgrpc "gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/grpc/opts"
+	optshttp "gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/http/opts"
+
+	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/config"
+	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/demo/demogrpc"
+	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/demo/demohttp"
+	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/service"
+)
+
+type DemoService struct {
+	ctx    context.Context
+	config *config.ServiceConfig
+	http   *demohttp.DemoHTTPServer
+	grpc   *demogrpc.DemoGRPCServer
+}
+
+func (d *DemoService) Init(ctx context.Context, config *config.ServiceConfig,
+) (service.ShutdownFunc, error) {
+	d.config = config
+	d.ctx = ctx
+
+	// These don't HAVE to be split into separate packages
+	// This is, after all, a demo app. Just implement the interface.
+	d.http = demohttp.NewDemoHTTPServer(ctx, config)
+	d.grpc = demogrpc.NewDemoGRPCServer(ctx, config)
+
+	// TODO: This should actually do shutdown stuff
+	return func(_ context.Context) (string, error) {
+		return "DemoService", nil
+	}, nil
+}
+
+func (d *DemoService) GetGRPC() *optsgrpc.AppGRPC {
+	return &optsgrpc.AppGRPC{
+		Services:     d.grpc.GetServices(),
+		GRPCDialOpts: d.grpc.GetDialOpts(),
+	}
+}
+
+func (d *DemoService) GetHTTP() *optshttp.AppHTTP {
+	return &optshttp.AppHTTP{
+		Ctx:          d.ctx,
+		Funcs:        d.http.GetHandleFuncs(),
+		HealthChecks: d.http.GetHealthCheckFuncs(),
+	}
+}

pkg/demo/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.ServiceConfig
+	client *resty.Client
+	pb.UnimplementedDemoAppServiceServer
+}
+
+func NewDemoGRPCServer(ctx context.Context, cfg *config.ServiceConfig) *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
+}

pkg/demo/demogrpc/fact.go

@@ -0,0 +1,25 @@
+package demogrpc
+
+import (
+	"google.golang.org/protobuf/types/known/timestamppb"
+
+	pb "gitea.libretechconsulting.com/rmcguire/go-server-with-otel/api/demo/app/v1alpha1"
+)
+
+type RandomFact struct {
+	ID        string `json:"id,omitempty"`
+	Text      string `json:"text,omitempty"`
+	Source    string `json:"source,omitempty"`
+	SourceURL string `json:"source_url,omitempty"`
+	Language  string `json:"language,omitempty"`
+	Permalink string `json:"permalink,omitempty"`
+}
+
+func (f *RandomFact) FactToProto() *pb.GetDemoResponse {
+	return &pb.GetDemoResponse{
+		Timestamp: timestamppb.Now(),
+		Fact:      f.Text,
+		Source:    f.SourceURL,
+		Language:  f.Language,
+	}
+}

pkg/demo/demogrpc/server.go

@@ -0,0 +1,30 @@
+package demogrpc
+
+import (
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/grpc/opts"
+	"google.golang.org/grpc"
+	"google.golang.org/grpc/credentials/insecure"
+
+	demoAppPb "gitea.libretechconsulting.com/rmcguire/go-server-with-otel/api/demo/app/v1alpha1"
+)
+
+func (ds *DemoGRPCServer) GetDialOpts() []grpc.DialOption {
+	return []grpc.DialOption{
+		// NOTE: Necessary for grpc-gateway to connect to grpc server
+		// Update if grpc service has credentials, tls, etc..
+		grpc.WithTransportCredentials(insecure.NewCredentials()),
+	}
+}
+
+func (ds *DemoGRPCServer) GetServices() []*opts.GRPCService {
+	return []*opts.GRPCService{
+		{
+			Name:    "Demo App",
+			Type:    &demoAppPb.DemoAppService_ServiceDesc,
+			Service: ds,
+			GwRegistrationFuncs: []opts.GwRegistrationFunc{
+				demoAppPb.RegisterDemoAppServiceHandler,
+			},
+		},
+	}
+}

pkg/demo/demohttp/server.go

@@ -0,0 +1,44 @@
+package demohttp
+
+import (
+	"context"
+	"net/http"
+
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/http/opts"
+
+	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/config"
+)
+
+type DemoHTTPServer struct {
+	ctx context.Context
+	cfg *config.ServiceConfig
+}
+
+func NewDemoHTTPServer(ctx context.Context, cfg *config.ServiceConfig) *DemoHTTPServer {
+	return &DemoHTTPServer{
+		ctx: ctx,
+		cfg: cfg,
+	}
+}
+
+func (dh *DemoHTTPServer) GetHandleFuncs() []opts.HTTPFunc {
+	// TODO: Implement real http handle funcs
+	return []opts.HTTPFunc{
+		{
+			Path: "/test",
+			HandlerFunc: func(w http.ResponseWriter, r *http.Request) {
+				w.WriteHeader(http.StatusNotImplemented)
+				w.Write([]byte("unimplemented demo app"))
+			},
+		},
+	}
+}
+
+func (dh *DemoHTTPServer) GetHealthCheckFuncs() []opts.HealthCheckFunc {
+	return []opts.HealthCheckFunc{
+		func(ctx context.Context) error {
+			// TODO: Implement real health checks
+			return nil
+		},
+	}
+}