improve shutdown and app service boilerplate

pkg/config/custom.go

@@ -1,13 +1,14 @@
-// This serves as a reference sample configuration
-// to show how to merge custom config fields into
-// go-app configuration
+// Package config contains ServiceConfig, which is intended
+// to extend go-app/pkg/config.AppConfig. Add any custom fields
+// here, and it will automatically be handled by go-app, including
+// overrides by environment, and json schema generation
 package config
 
 import (
 	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/config"
 )
 
-type DemoConfig struct {
+type ServiceConfig struct {
 	Timezone string    `yaml:"timezone" json:"timezone,omitempty" default:"UTC"`
 	Opts     *DemoOpts `yaml:"opts" json:"opts,omitempty"`
 

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

@@ -27,12 +27,12 @@ const (
 type DemoGRPCServer struct {
 	tracer trace.Tracer
 	ctx    context.Context
-	cfg    *config.DemoConfig
+	cfg    *config.ServiceConfig
 	client *resty.Client
 	pb.UnimplementedDemoAppServiceServer
 }
 
-func NewDemoGRPCServer(ctx context.Context, cfg *config.DemoConfig) *DemoGRPCServer {
+func NewDemoGRPCServer(ctx context.Context, cfg *config.ServiceConfig) *DemoGRPCServer {
 	if cfg.Opts == nil {
 		cfg.Opts = &config.DemoOpts{}
 	}

pkg/demo/demohttp/server.go

@@ -11,10 +11,10 @@ import (
 
 type DemoHTTPServer struct {
 	ctx context.Context
-	cfg *config.DemoConfig
+	cfg *config.ServiceConfig
 }
 
-func NewDemoHTTPServer(ctx context.Context, cfg *config.DemoConfig) *DemoHTTPServer {
+func NewDemoHTTPServer(ctx context.Context, cfg *config.ServiceConfig) *DemoHTTPServer {
 	return &DemoHTTPServer{
 		ctx: ctx,
 		cfg: cfg,

pkg/service/service.go

@@ -0,0 +1,63 @@
+// Package service defines generics around implementation of
+// a new service that provides configuration for go-app
+//
+// The interface is meant to make the template more clear to implement
+// without unnecessary changes in main.go
+package service
+
+import (
+	"context"
+
+	"gitea.libretechconsulting.com/rmcguire/go-server-with-otel/pkg/config"
+
+	optsgrpc "gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/grpc/opts"
+	optshttp "gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv/http/opts"
+)
+
+type ShutdownFunc func(ctx context.Context) (string, error)
+
+type AppService interface {
+	Init(ctx context.Context, config *config.ServiceConfig) (ShutdownFunc, error)
+	GetGRPC() *optsgrpc.AppGRPC
+	GetHTTP() *optshttp.AppHTTP
+}
+
+// MergeServices is used if multiple services are served by this server
+// with their own distinct packages and configuration
+//
+// You should be overriding the done chan, listener, or any other
+// configuration used by the SERVER rather than the individual services.
+func MergeServices(ctx context.Context, appServices ...AppService) (*optsgrpc.AppGRPC, *optshttp.AppHTTP) {
+	mergedGRPC := &optsgrpc.AppGRPC{}
+	for _, svc := range appServices {
+		mergedGRPC = mergeGRPC(mergedGRPC, svc.GetGRPC())
+	}
+
+	mergedHTTP := &optshttp.AppHTTP{}
+	for _, svc := range appServices {
+		mergedHTTP = mergeHTTP(mergedHTTP, svc.GetHTTP())
+	}
+	mergedHTTP.Ctx = ctx
+
+	return mergedGRPC, mergedHTTP
+}
+
+func mergeHTTP(a *optshttp.AppHTTP, b *optshttp.AppHTTP) *optshttp.AppHTTP {
+	return &optshttp.AppHTTP{
+		Funcs:        append(a.Funcs, b.Funcs...),
+		Middleware:   append(a.Middleware, b.Middleware...),
+		Handlers:     append(a.Handlers, b.Handlers...),
+		HealthChecks: append(a.HealthChecks, b.HealthChecks...),
+	}
+}
+
+func mergeGRPC(a *optsgrpc.AppGRPC, b *optsgrpc.AppGRPC) *optsgrpc.AppGRPC {
+	return &optsgrpc.AppGRPC{
+		Services:           append(a.Services, b.Services...),
+		GRPCOpts:           append(a.GRPCOpts, b.GRPCOpts...),
+		UnaryInterceptors:  append(a.UnaryInterceptors, b.UnaryInterceptors...),
+		StreamInterceptors: append(a.StreamInterceptors, b.StreamInterceptors...),
+		GRPCDialOpts:       append(a.GRPCDialOpts, b.GRPCDialOpts...),
+		GRPCGatewayOpts:    append(a.GRPCGatewayOpts, b.GRPCGatewayOpts...),
+	}
+}