add grpc support

TODO.md

@@ -1,8 +1,10 @@
 # TODO
 
-- [x] Pattern for extending config
+- [ ] Finish implementing GRPC service support
+- [ ] Expand tracing
 
 ## Done
 - [x] Unit tests
+- [x] Pattern for extending config
 - [x] HTTP Logging Middleware
 - [x] Fix panic with OTEL disabled

pkg/app/app.go

@@ -1,42 +1,15 @@
 package app
 
 import (
-	"context"
 	"errors"
-	"net/http"
 
 	"github.com/rs/zerolog"
 	"go.opentelemetry.io/otel/codes"
-	"go.opentelemetry.io/otel/trace"
 
 	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/config"
-	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/otel"
-	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv"
 )
 
-type App struct {
+func (a *App) Done() <-chan any {
-	AppContext    context.Context
-	HTTP          *AppHTTP
-	cfg           *config.AppConfig
-	l             *zerolog.Logger
-	tracer        trace.Tracer
-	shutdownFuncs []shutdownFunc
-	appDone       chan interface{}
-}
-
-type AppHTTP struct {
-	Funcs        []srv.HTTPFunc
-	Middleware   []http.Handler
-	HealthChecks []srv.HealthCheckFunc
-	httpDone     <-chan interface{}
-}
-
-type (
-	healthCheckFunc func(context.Context) error
-	shutdownFunc    func(context.Context) error
-)
-
-func (a *App) Done() <-chan interface{} {
 	return a.appDone
 }
 
@@ -49,8 +22,8 @@ func (a *App) MustRun() {
 	a.cfg = config.MustFromCtx(a.AppContext)
 	a.l = zerolog.Ctx(a.AppContext)
 	a.shutdownFuncs = make([]shutdownFunc, 0)
-	a.appDone = make(chan interface{})
+	a.appDone = make(chan any)
-	a.HTTP.httpDone = make(chan interface{})
+	a.HTTP.httpDone = make(chan any)
 
 	if len(a.HTTP.Funcs) < 1 {
 		a.l.Warn().Msg("no http funcs provided, only serving health and metrics")
@@ -58,11 +31,17 @@ func (a *App) MustRun() {
 
 	// Start OTEL
 	a.initOTEL()
-	var initSpan trace.Span
+	ctx, initSpan := a.tracer.Start(a.AppContext, "init")
-	_, initSpan = a.tracer.Start(a.AppContext, "init")
+	defer initSpan.End()
 
 	// Start HTTP
-	a.initHTTP()
+	if err := a.initHTTP(ctx); err != nil {
+		initSpan.RecordError(err)
+		initSpan.SetStatus(codes.Error, err.Error())
+	}
+
+	// Start GRPC
+	a.initGRPC()
 
 	// Monitor app lifecycle
 	go a.run()
@@ -74,25 +53,4 @@ func (a *App) MustRun() {
 		Str("logLevel", a.cfg.Logging.Level).
 		Msg("app initialized")
 	initSpan.SetStatus(codes.Ok, "")
-	initSpan.End()
-}
-
-func (a *App) initHTTP() {
-	var httpShutdown shutdownFunc
-	httpShutdown, a.HTTP.httpDone = srv.MustInitHTTPServer(
-		&srv.HTTPServerOpts{
-			Ctx:              a.AppContext,
-			HandleFuncs:      a.HTTP.Funcs,
-			Middleware:       a.HTTP.Middleware,
-			HealthCheckFuncs: a.HTTP.HealthChecks,
-		},
-	)
-	a.shutdownFuncs = append(a.shutdownFuncs, httpShutdown)
-}
-
-func (a *App) initOTEL() {
-	var otelShutdown shutdownFunc
-	a.AppContext, otelShutdown = otel.Init(a.AppContext)
-	a.shutdownFuncs = append(a.shutdownFuncs, otelShutdown)
-	a.tracer = otel.MustTracerFromCtx(a.AppContext)
 }

pkg/app/app_init.go

@@ -0,0 +1,55 @@
+package app
+
+import (
+	"context"
+
+	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/codes"
+
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/otel"
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv"
+)
+
+func (a *App) initGRPC() {
+}
+
+func (a *App) initHTTP(ctx context.Context) error {
+	var err error
+	var httpShutdown shutdownFunc
+
+	_, span := a.tracer.Start(ctx, "init.http")
+	defer span.End()
+
+	span.SetAttributes(
+		attribute.Int("numHTTPFuncs", len(a.HTTP.Funcs)),
+		attribute.Int("numHTTPMiddlewares", len(a.HTTP.Middleware)),
+		attribute.Int("numHTTPHealthChecks", len(a.HTTP.HealthChecks)),
+	)
+
+	httpShutdown, a.HTTP.httpDone, err = srv.InitHTTPServer(
+		&srv.HTTPServerOpts{
+			Ctx:              a.AppContext,
+			HandleFuncs:      a.HTTP.Funcs,
+			Middleware:       a.HTTP.Middleware,
+			HealthCheckFuncs: a.HTTP.HealthChecks,
+		},
+	)
+
+	a.shutdownFuncs = append(a.shutdownFuncs, httpShutdown)
+
+	if err != nil {
+		span.RecordError(err)
+		span.SetStatus(codes.Error, err.Error())
+	} else {
+		span.SetStatus(codes.Ok, "")
+	}
+
+	return err
+}
+
+func (a *App) initOTEL() {
+	var otelShutdown shutdownFunc
+	a.AppContext, otelShutdown = otel.Init(a.AppContext)
+	a.shutdownFuncs = append(a.shutdownFuncs, otelShutdown)
+	a.tracer = otel.MustTracerFromCtx(a.AppContext)
+}

pkg/app/app_types.go

@@ -0,0 +1,47 @@
+package app
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/rs/zerolog"
+	"go.opentelemetry.io/otel/trace"
+	"google.golang.org/grpc"
+
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/config"
+	"gitea.libretechconsulting.com/rmcguire/go-app/pkg/srv"
+)
+
+type App struct {
+	AppContext    context.Context
+	HTTP          *AppHTTP
+	GRPC          *AppGRPC
+	cfg           *config.AppConfig
+	l             *zerolog.Logger
+	tracer        trace.Tracer
+	shutdownFuncs []shutdownFunc
+	appDone       chan any
+}
+
+type AppGRPC struct {
+	Services []*GRPCService
+	GRPCOpts []grpc.ServerOption
+}
+
+type GRPCService struct {
+	Name    string            // Descriptive name of service
+	Type    *grpc.ServiceDesc // Type (from protoc generated code)
+	Service any               // Implementation of GRPCService.Type (ptr)
+}
+
+type AppHTTP struct {
+	Funcs        []srv.HTTPFunc
+	Middleware   []http.Handler
+	HealthChecks []srv.HealthCheckFunc
+	httpDone     <-chan any
+}
+
+type (
+	healthCheckFunc func(context.Context) error
+	shutdownFunc    func(context.Context) error
+)

pkg/config/types.go

@@ -1,32 +1,13 @@
 package config
 
-import "time"
-
 // Default Settings
 var DefaultConfig = &AppConfig{
 	Environment: "development",
 	Version:     getVersion(),
-	Logging: &LogConfig{
+	Logging:     defaultLoggingConfig,
-		Enabled:    true,
+	HTTP:        defaultHTTPConfig,
-		Level:      "info",
+	OTEL:        defaultOTELConfig,
-		Format:     LogFormatJSON,
+	GRPC:        defaultGRPCConfig,
-		Output:     "stderr",
-		TimeFormat: TimeFormatLong,
-	},
-	HTTP: &HTTPConfig{
-		Listen:       "127.0.0.1:8080",
-		LogRequests:  false,
-		ReadTimeout:  "10s",
-		WriteTimeout: "10s",
-		IdleTimeout:  "1m",
-	},
-	OTEL: &OTELConfig{
-		Enabled:            true,
-		PrometheusEnabled:  true,
-		PrometheusPath:     "/metrics",
-		StdoutEnabled:      false,
-		MetricIntervalSecs: 30,
-	},
 }
 
 type AppConfig struct {
@@ -39,58 +20,5 @@ type AppConfig struct {
 	Logging *LogConfig  `yaml:"logging,omitempty"`
 	HTTP    *HTTPConfig `yaml:"http,omitempty"`
 	OTEL    *OTELConfig `yaml:"otel,omitempty"`
-}
+	GRPC    *GRPCConfig `yaml:"grpc,omitempty"`
-
-// Logging Configuration
-type LogConfig struct {
-	Enabled    bool       `yaml:"enabled,omitempty" env:"APP_LOG_ENABLED"`
-	Level      string     `yaml:"level,omitempty" env:"APP_LOG_LEVEL"`
-	Format     LogFormat  `yaml:"format,omitempty" env:"APP_LOG_FORMAT"`
-	Output     LogOutput  `yaml:"output,omitempty" env:"APP_LOG_OUTPUT"`
-	TimeFormat TimeFormat `yaml:"timeFormat,omitempty" env:"APP_LOG_TIME_FORMAT"`
-}
-
-type LogFormat string
-
-const (
-	LogFormatConsole LogFormat = "console"
-	LogFormatJSON    LogFormat = "json"
-)
-
-type TimeFormat string
-
-const (
-	TimeFormatShort   TimeFormat = "short"
-	TimeFormatLong    TimeFormat = "long"
-	TimeFormatUnix    TimeFormat = "unix"
-	TimeFormatRFC3339 TimeFormat = "rfc3339"
-	TimeFormatOff     TimeFormat = "off"
-)
-
-type LogOutput string
-
-const (
-	LogOutputStdout LogOutput = "stdout"
-	LogOutputStderr LogOutput = "stderr"
-)
-
-// HTTP Configuration
-type HTTPConfig struct {
-	Listen       string `yaml:"listen,omitempty" env:"APP_HTTP_LISTEN"`
-	LogRequests  bool   `yaml:"logRequests" env:"APP_HTTP_LOG_REQUESTS"`
-	ReadTimeout  string `yaml:"readTimeout" env:"APP_HTTP_READ_TIMEOUT"`   // Go duration (e.g. 10s)
-	WriteTimeout string `yaml:"writeTimeout" env:"APP_HTTP_WRITE_TIMEOUT"` // Go duration (e.g. 10s)
-	IdleTimeout  string `yaml:"idleTimeout" env:"APP_HTTP_IDLE_TIMEOUT"`   // Go duration (e.g. 10s)
-	rT           *time.Duration
-	wT           *time.Duration
-	iT           *time.Duration
-}
-
-// OTEL Configuration
-type OTELConfig struct {
-	Enabled            bool   `yaml:"enabled,omitempty" env:"APP_OTEL_ENABLED"`
-	PrometheusEnabled  bool   `yaml:"prometheusEnabled,omitempty" env:"APP_OTEL_PROMETHEUS_ENABLED"`
-	PrometheusPath     string `yaml:"prometheusPath,omitempty" env:"APP_OTEL_PROMETHEUS_PATH"`
-	StdoutEnabled      bool   `yaml:"stdoutEnabled,omitempty" env:"APP_OTEL_STDOUT_ENABLED"`
-	MetricIntervalSecs int    `yaml:"metricIntervalSecs,omitempty" env:"APP_OTEL_METRIC_INTERVAL_SECS"`
 }

pkg/config/types_grpc.go

@@ -0,0 +1,14 @@
+package config
+
+var defaultGRPCConfig = &GRPCConfig{
+	LogRequests:           false,
+	EnableReflection:      true,
+	EnableInstrumentation: true,
+}
+
+type GRPCConfig struct {
+	Listen                string `yaml:"listen" env:"APP_GRPC_LISTEN"`
+	LogRequests           bool   `yaml:"logRequests" env:"APP_GRPC_LOG_REQUESTS"`
+	EnableReflection      bool   `yaml:"enableReflection" env:"APP_GRPC_ENABLE_REFLECTION"`
+	EnableInstrumentation bool   `yaml:"enableInstrumentation" env:"APP_GRPC_ENABLE_INSTRUMENTATION"` // requires OTEL
+}

pkg/config/types_http.go

@@ -0,0 +1,23 @@
+package config
+
+import "time"
+
+var defaultHTTPConfig = &HTTPConfig{
+	Listen:       "127.0.0.1:8080",
+	LogRequests:  false,
+	ReadTimeout:  "10s",
+	WriteTimeout: "10s",
+	IdleTimeout:  "1m",
+}
+
+// HTTP Configuration
+type HTTPConfig struct {
+	Listen       string `yaml:"listen,omitempty" env:"APP_HTTP_LISTEN"`
+	LogRequests  bool   `yaml:"logRequests" env:"APP_HTTP_LOG_REQUESTS"`
+	ReadTimeout  string `yaml:"readTimeout" env:"APP_HTTP_READ_TIMEOUT"`   // Go duration (e.g. 10s)
+	WriteTimeout string `yaml:"writeTimeout" env:"APP_HTTP_WRITE_TIMEOUT"` // Go duration (e.g. 10s)
+	IdleTimeout  string `yaml:"idleTimeout" env:"APP_HTTP_IDLE_TIMEOUT"`   // Go duration (e.g. 10s)
+	rT           *time.Duration
+	wT           *time.Duration
+	iT           *time.Duration
+}

pkg/config/types_logging.go

@@ -0,0 +1,42 @@
+package config
+
+var defaultLoggingConfig = &LogConfig{
+	Enabled:    true,
+	Level:      "info",
+	Format:     LogFormatJSON,
+	Output:     "stderr",
+	TimeFormat: TimeFormatLong,
+}
+
+// Logging Configuration
+type LogConfig struct {
+	Enabled    bool       `yaml:"enabled,omitempty" env:"APP_LOG_ENABLED"`
+	Level      string     `yaml:"level,omitempty" env:"APP_LOG_LEVEL"`
+	Format     LogFormat  `yaml:"format,omitempty" env:"APP_LOG_FORMAT"`
+	Output     LogOutput  `yaml:"output,omitempty" env:"APP_LOG_OUTPUT"`
+	TimeFormat TimeFormat `yaml:"timeFormat,omitempty" env:"APP_LOG_TIME_FORMAT"`
+}
+
+type LogFormat string
+
+const (
+	LogFormatConsole LogFormat = "console"
+	LogFormatJSON    LogFormat = "json"
+)
+
+type TimeFormat string
+
+const (
+	TimeFormatShort   TimeFormat = "short"
+	TimeFormatLong    TimeFormat = "long"
+	TimeFormatUnix    TimeFormat = "unix"
+	TimeFormatRFC3339 TimeFormat = "rfc3339"
+	TimeFormatOff     TimeFormat = "off"
+)
+
+type LogOutput string
+
+const (
+	LogOutputStdout LogOutput = "stdout"
+	LogOutputStderr LogOutput = "stderr"
+)

pkg/config/types_otel.go

@@ -0,0 +1,18 @@
+package config
+
+var defaultOTELConfig = &OTELConfig{
+	Enabled:            true,
+	PrometheusEnabled:  true,
+	PrometheusPath:     "/metrics",
+	StdoutEnabled:      false,
+	MetricIntervalSecs: 30,
+}
+
+// OTEL Configuration
+type OTELConfig struct {
+	Enabled            bool   `yaml:"enabled,omitempty" env:"APP_OTEL_ENABLED"`
+	PrometheusEnabled  bool   `yaml:"prometheusEnabled,omitempty" env:"APP_OTEL_PROMETHEUS_ENABLED"`
+	PrometheusPath     string `yaml:"prometheusPath,omitempty" env:"APP_OTEL_PROMETHEUS_PATH"`
+	StdoutEnabled      bool   `yaml:"stdoutEnabled,omitempty" env:"APP_OTEL_STDOUT_ENABLED"`
+	MetricIntervalSecs int    `yaml:"metricIntervalSecs,omitempty" env:"APP_OTEL_METRIC_INTERVAL_SECS"`
+}

pkg/srv/http.go

@@ -129,23 +129,19 @@ func prepHTTPServer(opts *HTTPServerOpts) *http.Server {
 
 // Returns a shutdown func and a done channel if the
 // server aborts abnormally. Panics on error.
-func MustInitHTTPServer(opts *HTTPServerOpts) (
+func InitHTTPServer(opts *HTTPServerOpts) (
-	func(context.Context) error, <-chan interface{},
+	func(context.Context) error, <-chan any, error,
 ) {
-	shutdownFunc, doneChan, err := InitHTTPServer(opts)
+	return initHTTPServer(opts)
-	if err != nil {
-		panic(err)
-	}
-	return shutdownFunc, doneChan
 }
 
 // Returns a shutdown func and a done channel if the
 // server aborts abnormally. Returns error on failure to start
-func InitHTTPServer(opts *HTTPServerOpts) (
+func initHTTPServer(opts *HTTPServerOpts) (
-	func(context.Context) error, <-chan interface{}, error,
+	func(context.Context) error, <-chan any, error,
 ) {
 	l := zerolog.Ctx(opts.Ctx)
-	doneChan := make(chan interface{})
+	doneChan := make(chan any)
 
 	var server *http.Server