support json schema

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/grpc-ecosystem/go-grpc-middleware/v2 v2.3.1
 	github.com/prometheus/client_golang v1.21.1
 	github.com/rs/zerolog v1.33.0
+	github.com/swaggest/jsonschema-go v0.3.73
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.60.0
 	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.60.0
 	go.opentelemetry.io/otel v1.35.0
@@ -39,6 +40,7 @@ require (
 	github.com/prometheus/client_model v0.6.1 // indirect
 	github.com/prometheus/common v0.62.0 // indirect
 	github.com/prometheus/procfs v0.15.1 // indirect
+	github.com/swaggest/refl v1.3.0 // indirect
 	go.opentelemetry.io/auto/sdk v1.1.0 // indirect
 	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.35.0 // indirect
 	go.opentelemetry.io/proto/otlp v1.5.0 // indirect

go.sum

@@ -75,6 +75,10 @@ github.com/rs/zerolog v1.33.0 h1:1cU2KZkvPxNyfgEmhHAz/1A9Bz+llsdYzklWFzgp0r8=
 github.com/rs/zerolog v1.33.0/go.mod h1:/7mN4D5sKwJLZQ2b/znpjC3/GQWY/xaDXUM0kKWRHss=
 github.com/stretchr/testify v1.10.0 h1:Xv5erBjTwe/5IxqUQTdXv5kgmIvbHo3QQyRwhJsOfJA=
 github.com/stretchr/testify v1.10.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+github.com/swaggest/jsonschema-go v0.3.73 h1:gU1pBzF3pkZ1GDD3dRMdQoCjrA0sldJ+QcM7aSSPgvc=
+github.com/swaggest/jsonschema-go v0.3.73/go.mod h1:qp+Ym2DIXHlHzch3HKz50gPf2wJhKOrAB/VYqLS2oJU=
+github.com/swaggest/refl v1.3.0 h1:PEUWIku+ZznYfsoyheF97ypSduvMApYyGkYF3nabS0I=
+github.com/swaggest/refl v1.3.0/go.mod h1:3Ujvbmh1pfSbDYjC6JGG7nMgPvpG0ehQL4iNonnLNbg=
 go.opentelemetry.io/auto/sdk v1.1.0 h1:cH53jehLUN6UFLY71z+NDOiNJqDdPRaXzTel0sJySYA=
 go.opentelemetry.io/auto/sdk v1.1.0/go.mod h1:3wSPjt5PWp2RhlCcmmOial7AvC4DQqZb7a7wCow3W8A=
 go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.60.0 h1:x7wzEgXfnzJcHDwStJT+mxOz4etr2EcexjqhBvmoakw=

pkg/app/app.go

@@ -2,6 +2,7 @@ package app
 
 import (
 	"errors"
+	"sync"
 
 	"github.com/rs/zerolog"
 	"go.opentelemetry.io/otel/attribute"
@@ -17,8 +18,6 @@ func (a *App) Done() <-chan any {
 func (a *App) MustRun() {
 	if a.cfg != nil {
 		panic(errors.New("already ran app trying to run"))
-	} else if !a.cfg.HTTP.Enabled && !a.cfg.GRPC.Enabled {
-		panic(errors.New("neither http nor grpc enabled, nothing to do"))
 	}
 
 	// Set up app
@@ -28,35 +27,53 @@ func (a *App) MustRun() {
 	a.appDone = make(chan any)
 	a.HTTP.HTTPDone = make(chan any)
 
+	if !a.cfg.HTTPEnabled() && !a.cfg.GRPCEnabled() {
+		panic(errors.New("neither http nor grpc enabled, nothing to do"))
+	}
+
 	if len(a.HTTP.Funcs) < 1 {
 		a.l.Warn().Msg("no http funcs provided, only serving health and metrics")
 	}
 
 	// Start OTEL
+	// Registers a NO-OP provider if not enabled
 	a.initOTEL()
+
 	ctx, initSpan := a.tracer.Start(a.AppContext, "init")
 	defer initSpan.End()
 
+	var serverWG sync.WaitGroup
+
 	// Start HTTP (does not block)
-	if a.cfg.HTTP.Enabled {
-		if err := a.initHTTP(ctx); err != nil {
-			initSpan.RecordError(err)
-			initSpan.SetStatus(codes.Error, err.Error())
-		}
-		initSpan.AddEvent("http server started")
-		initSpan.SetAttributes(attribute.Int("http.handlers", len(a.HTTP.Funcs)))
+	if a.cfg.HTTPEnabled() {
+		serverWG.Add(1)
+		go func() {
+			defer serverWG.Done()
+			if err := a.initHTTP(ctx); err != nil {
+				initSpan.RecordError(err)
+				initSpan.SetStatus(codes.Error, err.Error())
+			}
+			initSpan.AddEvent("http server started")
+			initSpan.SetAttributes(attribute.Int("http.handlers", len(a.HTTP.Funcs)))
+		}()
 	}
 
 	// Start GRPC (does not block)
-	if a.cfg.GRPC.Enabled {
-		if err := a.initGRPC(ctx); err != nil {
-			initSpan.RecordError(err)
-			initSpan.SetStatus(codes.Error, err.Error())
-		}
-		initSpan.AddEvent("grpc server started")
-		initSpan.SetAttributes(attribute.Int("grpc.services", len(a.GRPC.Services)))
+	if a.cfg.GRPCEnabled() {
+		serverWG.Add(1)
+		go func() {
+			defer serverWG.Done()
+			if err := a.initGRPC(ctx); err != nil {
+				initSpan.RecordError(err)
+				initSpan.SetStatus(codes.Error, err.Error())
+			}
+			initSpan.AddEvent("grpc server started")
+			initSpan.SetAttributes(attribute.Int("grpc.services", len(a.GRPC.Services)))
+		}()
 	}
 
+	serverWG.Wait()
+
 	// Monitor app lifecycle
 	go a.run()
 

pkg/app/schema.go

@@ -0,0 +1,40 @@
+package app
+
+import (
+	"encoding/json"
+
+	js "github.com/swaggest/jsonschema-go"
+)
+
+// Generates json schema for app's config.AppConfig
+func (app *App) Schema() ([]byte, error) {
+	r := js.Reflector{}
+
+	s, err := r.Reflect(*app.cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	return json.MarshalIndent(s, "", "  ")
+}
+
+// Generates json schema for custom config
+// which embeds *config.AppConfig into it
+// Panics if no *config.AppConfig is embedded into custom
+// config type
+//
+// See swaggest/jsonschema-go for struct tag docs
+func CustomSchema[T any](target T) ([]byte, error) {
+	if err := HasAppConfig(target); err != nil {
+		panic(err.Error())
+	}
+
+	r := js.Reflector{}
+
+	s, err := r.Reflect(target)
+	if err != nil {
+		return nil, err
+	}
+
+	return json.MarshalIndent(s, "", "  ")
+}

pkg/app/setup_custom.go

@@ -19,7 +19,7 @@ import (
 // are up to the caller.
 func MustLoadConfigInto[T any](ctx context.Context, into T) (context.Context, T) {
 	// Step 1: Check our custom type for required *config.AppConfig
-	if err := hasAppConfig(into); err != nil {
+	if err := HasAppConfig(into); err != nil {
 		panic(err)
 	}
 
@@ -66,7 +66,7 @@ func setAppConfig[T any](target T, appConfig *config.AppConfig) error {
 	}
 
 	// Replace *config.AppConfig
-	for i := 0; i < v.NumField(); i++ {
+	for i := range v.NumField() {
 		field := v.Field(i)
 		if field.Type() == reflect.TypeOf((*config.AppConfig)(nil)) {
 			if !field.CanSet() {
@@ -80,7 +80,7 @@ func setAppConfig[T any](target T, appConfig *config.AppConfig) error {
 	return errors.New("no *config.AppConfig field found in target struct")
 }
 
-func hasAppConfig[T any](target T) error {
+func HasAppConfig[T any](target T) error {
 	v := reflect.ValueOf(target)
 	if v.Kind() != reflect.Ptr || v.IsNil() {
 		return errors.New("target must be a non-nil pointer to a struct")
@@ -92,7 +92,7 @@ func hasAppConfig[T any](target T) error {
 	}
 
 	hasAppConfig := false
-	for i := 0; i < v.NumField(); i++ {
+	for i := range v.NumField() {
 		field := v.Type().Field(i)
 		if field.Type == reflect.TypeOf((*config.AppConfig)(nil)) {
 			hasAppConfig = true

pkg/config/types.go

@@ -11,14 +11,35 @@ var DefaultConfig = &AppConfig{
 }
 
 type AppConfig struct {
-	Name        string `yaml:"name,omitempty" env:"APP_NAME"`
-	Environment string `yaml:"environment,omitempty" env:"APP_ENVIRONMENT"`
+	Name        string `yaml:"name,omitempty" env:"APP_NAME" json:"name,omitempty"`
+	Environment string `yaml:"environment,omitempty" env:"APP_ENVIRONMENT" json:"environment,omitempty"`
 	// This should either be set by ldflags, such as with
 	// go build -ldflags "-X gitea.libretechconsulting.com/rmcguire/go-app/pkg/config.Version=$(VERSION)"
 	// or allow this to use build meta. Will default to (devel)
-	Version string      `yaml:"version,omitempty" env:"APP_VERSION"`
-	Logging *LogConfig  `yaml:"logging,omitempty"`
-	HTTP    *HTTPConfig `yaml:"http,omitempty"`
-	OTEL    *OTELConfig `yaml:"otel,omitempty"`
-	GRPC    *GRPCConfig `yaml:"grpc,omitempty"`
+	Version string      `yaml:"version,omitempty" env:"APP_VERSION" json:"version,omitempty"`
+	Logging *LogConfig  `yaml:"logging,omitempty" json:"logging,omitempty"`
+	HTTP    *HTTPConfig `yaml:"http,omitempty" json:"http,omitempty"`
+	OTEL    *OTELConfig `yaml:"otel,omitempty" json:"otel,omitempty"`
+	GRPC    *GRPCConfig `yaml:"grpc,omitempty" json:"grpc,omitempty"`
+}
+
+func (ac *AppConfig) HTTPEnabled() bool {
+	if ac.HTTP != nil && ac.HTTP.Enabled {
+		return true
+	}
+	return false
+}
+
+func (ac *AppConfig) GRPCEnabled() bool {
+	if ac.GRPC != nil && ac.GRPC.Enabled {
+		return true
+	}
+	return false
+}
+
+func (ac *AppConfig) OTELEnabled() bool {
+	if ac.OTEL != nil && ac.OTEL.Enabled {
+		return true
+	}
+	return false
 }

pkg/config/types_grpc.go

@@ -10,9 +10,9 @@ var defaultGRPCConfig = &GRPCConfig{
 }
 
 type GRPCConfig struct {
-	Enabled               bool   `yaml:"enabled" env:"APP_GRPC_ENABLED"`
-	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
+	Enabled               bool   `yaml:"enabled" env:"APP_GRPC_ENABLED" json:"enabled,omitempty"`
+	Listen                string `yaml:"listen" env:"APP_GRPC_LISTEN" json:"listen,omitempty"`
+	LogRequests           bool   `yaml:"logRequests" env:"APP_GRPC_LOG_REQUESTS" json:"logRequests,omitempty"`
+	EnableReflection      bool   `yaml:"enableReflection" env:"APP_GRPC_ENABLE_REFLECTION" json:"enableReflection,omitempty"`
+	EnableInstrumentation bool   `yaml:"enableInstrumentation" env:"APP_GRPC_ENABLE_INSTRUMENTATION" json:"enableInstrumentation,omitempty"` // requires OTEL
 }

pkg/config/types_http.go

@@ -14,13 +14,13 @@ var defaultHTTPConfig = &HTTPConfig{
 
 // HTTP Configuration
 type HTTPConfig struct {
-	Enabled      bool           `yaml:"enabled" env:"APP_HTTP_ENABLED"`
-	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 `yaml:"rT" env:"rT"`
-	wT           *time.Duration `yaml:"wT" env:"wT"`
-	iT           *time.Duration `yaml:"iT" env:"iT"`
+	Enabled      bool   `yaml:"enabled" env:"APP_HTTP_ENABLED" json:"enabled,omitempty"`
+	Listen       string `yaml:"listen,omitempty" env:"APP_HTTP_LISTEN" json:"listen,omitempty"`
+	LogRequests  bool   `yaml:"logRequests" env:"APP_HTTP_LOG_REQUESTS" json:"logRequests,omitempty"`
+	ReadTimeout  string `yaml:"readTimeout" env:"APP_HTTP_READ_TIMEOUT" json:"readTimeout,omitempty"`    // Go duration (e.g. 10s)
+	WriteTimeout string `yaml:"writeTimeout" env:"APP_HTTP_WRITE_TIMEOUT" json:"writeTimeout,omitempty"` // Go duration (e.g. 10s)
+	IdleTimeout  string `yaml:"idleTimeout" env:"APP_HTTP_IDLE_TIMEOUT" json:"idleTimeout,omitempty"`    // Go duration (e.g. 10s)
+	rT           *time.Duration
+	wT           *time.Duration
+	iT           *time.Duration
 }

pkg/config/types_logging.go

@@ -10,11 +10,11 @@ var defaultLoggingConfig = &LogConfig{
 
 // 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"`
+	Enabled    bool       `yaml:"enabled,omitempty" env:"APP_LOG_ENABLED" json:"enabled,omitempty"`
+	Level      string     `yaml:"level,omitempty" env:"APP_LOG_LEVEL" json:"level,omitempty"`
+	Format     LogFormat  `yaml:"format,omitempty" env:"APP_LOG_FORMAT" json:"format,omitempty"`
+	Output     LogOutput  `yaml:"output,omitempty" env:"APP_LOG_OUTPUT" json:"output,omitempty"`
+	TimeFormat TimeFormat `yaml:"timeFormat,omitempty" env:"APP_LOG_TIME_FORMAT" json:"timeFormat,omitempty"`
 }
 
 type LogFormat string

pkg/config/types_otel.go

@@ -10,9 +10,9 @@ var defaultOTELConfig = &OTELConfig{
 
 // 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"`
+	Enabled            bool   `yaml:"enabled,omitempty" env:"APP_OTEL_ENABLED" json:"enabled,omitempty"`
+	PrometheusEnabled  bool   `yaml:"prometheusEnabled,omitempty" env:"APP_OTEL_PROMETHEUS_ENABLED" json:"prometheusEnabled,omitempty"`
+	PrometheusPath     string `yaml:"prometheusPath,omitempty" env:"APP_OTEL_PROMETHEUS_PATH" json:"prometheusPath,omitempty"`
+	StdoutEnabled      bool   `yaml:"stdoutEnabled,omitempty" env:"APP_OTEL_STDOUT_ENABLED" json:"stdoutEnabled,omitempty"`
+	MetricIntervalSecs int    `yaml:"metricIntervalSecs,omitempty" env:"APP_OTEL_METRIC_INTERVAL_SECS" json:"metricIntervalSecs,omitempty"`
 }

pkg/logging/logging.go

@@ -38,7 +38,7 @@ func configureLogger(cfg *config.LogConfig) (*zerolog.Logger, error) {
 			TimeFormat: zerolog.TimeFieldFormat,
 		}
 		if cfg.TimeFormat == config.TimeFormatOff {
-			consoleWriter.FormatTimestamp = func(_ interface{}) string {
+			consoleWriter.FormatTimestamp = func(_ any) string {
 				return ""
 			}
 		}

pkg/otel/otel.go

@@ -44,7 +44,7 @@ func Init(ctx context.Context) (context.Context, func(context.Context) error) {
 	cfg := config.MustFromCtx(ctx)
 
 	// Nothing to do here if not enabled
-	if !cfg.OTEL.Enabled {
+	if !cfg.OTELEnabled() {
 		opentelemetry.SetMeterProvider(noopMetric.NewMeterProvider())
 		opentelemetry.SetTracerProvider(noop.NewTracerProvider())
 		// Won't function with noop providers