Improve logging setup in gRPC app

go.mod

@@ -18,7 +18,8 @@ require (
 	github.com/jdgcs/ed25519 v0.0.0-20200408034030-96c10d46cdc3
 	github.com/jmoiron/sqlx v1.4.0
 	github.com/mr-tron/base58 v1.2.0
-	github.com/newrelic/go-agent/v3 v3.20.1
+	github.com/newrelic/go-agent/v3 v3.40.1
+	github.com/newrelic/go-agent/v3/integrations/logcontext-v2/nrzap v1.2.4
 	github.com/newrelic/go-agent/v3/integrations/nrpgx v1.0.0
 	github.com/ory/dockertest/v3 v3.7.0
 	github.com/pbnjay/memory v0.0.0-20210728143218-7b4eea64cf58

go.sum

@@ -356,8 +356,10 @@ github.com/mr-tron/base58 v1.2.0 h1:T/HDJBh4ZCPbU39/+c3rRvE0uKBQlU27+QI8LJ4t64o=
 github.com/mr-tron/base58 v1.2.0/go.mod h1:BinMc/sQntlIE1frQmRFPUoPA1Zkr8VRgBdjWI2mNwc=
 github.com/mwitkow/go-conntrack v0.0.0-20161129095857-cc309e4a2223/go.mod h1:qRWi+5nqEBWmkhHvq77mSJWrCKwh8bxhgT7d/eI7P4U=
 github.com/newrelic/go-agent/v3 v3.3.0/go.mod h1:H28zDNUC0U/b7kLoY4EFOhuth10Xu/9dchozUiOseQQ=
-github.com/newrelic/go-agent/v3 v3.20.1 h1:xxhPjE/j4z7n82FQV4izRjIkd4E10q4flqgzMj+DlLM=
-github.com/newrelic/go-agent/v3 v3.20.1/go.mod h1:rT6ZUxJc5rQbWLyCtjqQCOcfb01lKRFbc1yMQkcboWM=
+github.com/newrelic/go-agent/v3 v3.40.1 h1:8nb4R252Fpuc3oySvlHpDwqySqaPWL5nf7ZVEhqtUeA=
+github.com/newrelic/go-agent/v3 v3.40.1/go.mod h1:X0TLXDo+ttefTIue1V96Y5seb8H6wqf6uUq4UpPsYj8=
+github.com/newrelic/go-agent/v3/integrations/logcontext-v2/nrzap v1.2.4 h1:Hf3pC0FNVhuO2AwruSRM4pyTBKHFaLohcF68dqScA64=
+github.com/newrelic/go-agent/v3/integrations/logcontext-v2/nrzap v1.2.4/go.mod h1:B+EpkW1/oOf6W3rprefGYXq7JIkhz3WR8nZNjZX3xqc=
 github.com/newrelic/go-agent/v3/integrations/nrpgx v1.0.0 h1:5pj3uXyWB0fpgbeK1yW51go6Y57uRG8F7w5Nu6kIiCQ=
 github.com/newrelic/go-agent/v3/integrations/nrpgx v1.0.0/go.mod h1:G4vsr8xgPwFxxwJSbE982D7rswRFEfoCaXPQWWWQyQo=
 github.com/niemeyer/pretty v0.0.0-20200227124842-a10e7caefd8e h1:fD57ERR4JtEqsWbfPhv4DMiApHyliiK5xCTNVSPiaAs=

grpc/app/app.go

@@ -14,6 +14,7 @@ import (
 	"time"
 
 	grpc_middleware "github.com/grpc-ecosystem/go-grpc-middleware"
+	"github.com/newrelic/go-agent/v3/integrations/logcontext-v2/nrzap"
 	"github.com/newrelic/go-agent/v3/newrelic"
 	"github.com/pkg/errors"
 	"github.com/robfig/cron/v3"
@@ -31,6 +32,8 @@ import (
 	"github.com/code-payments/ocp-server/osutil"
 )
 
+// todo: Better metrics provider abstraction so we're not directly tied to NR
+
 // App is a long lived application that services network requests.
 // It is expected that App's have gRPC services, but is not a hard requirement.
 //
@@ -41,10 +44,7 @@ type App interface {
 	// Init initializes the application in a blocking fashion. When Init returns, it
 	// is expected that the application is ready to start receiving requests (provided
 	// there are gRPC handlers installed).
-	//
-	// todo: I'm not very happy with passing the New Relic app here. It's a temporary
-	//       solution until we have something better in place.
-	Init(config Config, metricsProvider *newrelic.Application) error
+	Init(log *zap.Logger, metricsProvider *newrelic.Application, config Config) error
 
 	// RegisterWithGRPC provides a mechanism for the application to register gRPC services
 	// with the gRPC server.
@@ -73,9 +73,11 @@ func init() {
 	signal.Notify(osSigCh, syscall.SIGINT, syscall.SIGTERM, syscall.SIGQUIT, syscall.SIGHUP)
 }
 
-func Run(log *zap.Logger, app App, options ...Option) error {
+func Run(app App, options ...Option) error {
 	flag.Parse()
 
+	log := zap.New(getLogCore(zap.InfoLevel))
+
 	// viper.ReadInConfig only returns ConfigFileNotFoundError if it has to search
 	// for a default config file because one hasn't been explicitly set. That is,
 	// if we explicitly set a config file, and it does not exist, viper will not
@@ -100,12 +102,8 @@ func Run(log *zap.Logger, app App, options ...Option) error {
 		os.Exit(1)
 	}
 
-	if len(config.AppName) == 0 {
-		log.With(zap.Error(err)).Error("must specify an application name")
-		os.Exit(1)
-	}
+	log = zap.New(getLogCore(getLogLevel(config.LogLevel)))
 
-	// todo: Better abstraction so we're not directly tied to NR
 	var metricsProvider *newrelic.Application
 	if len(config.NewRelicLicenseKey) > 0 {
 		nr, err := newrelic.NewApplication(
@@ -121,6 +119,18 @@ func Run(log *zap.Logger, app App, options ...Option) error {
 		}
 
 		metricsProvider = nr
+
+		nrLogCore, err := nrzap.WrapBackgroundCore(getLogCore(getLogLevel(config.LogLevel)), metricsProvider)
+		if err != nil {
+			log.With(zap.Error(err)).Error("error wrapping logs with new relic")
+			return err
+		}
+		log = zap.New(nrLogCore)
+	}
+
+	if len(config.AppName) == 0 {
+		log.With(zap.Error(err)).Error("must specify an application name")
+		os.Exit(1)
 	}
 
 	// We don't want to expose pprof/expvar publically, so we reset the default
@@ -253,7 +263,7 @@ func Run(log *zap.Logger, app App, options ...Option) error {
 		o(&opts)
 	}
 
-	if err := app.Init(config.AppConfig, metricsProvider); err != nil {
+	if err := app.Init(log, metricsProvider, config.AppConfig); err != nil {
 		log.With(zap.Error(err)).Error("failed to initialize application")
 		os.Exit(1)
 	}

grpc/app/config.go

@@ -15,6 +15,8 @@ type Config map[string]interface{}
 type BaseConfig struct {
 	AppName string `mapstructure:"app_name"`
 
+	LogLevel string `mapstructure:"log_level"`
+
 	ListenAddress         string `mapstructure:"listen_address"`
 	InsecureListenAddress string `mapstructure:"insecure_listen_address"`
 	DebugListenAddress    string `mapstructure:"debug_listen_address"`
@@ -57,6 +59,8 @@ type BaseConfig struct {
 }
 
 var defaultConfig = BaseConfig{
+	LogLevel: "info",
+
 	ListenAddress:         ":8085",
 	InsecureListenAddress: "localhost:8086",
 	DebugListenAddress:    ":8123",

grpc/app/logging.go

@@ -0,0 +1,31 @@
+package app
+
+import (
+	"os"
+	"strings"
+
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+func getLogCore(level zapcore.LevelEnabler) zapcore.Core {
+	return zapcore.NewCore(
+		zapcore.NewJSONEncoder(zap.NewProductionEncoderConfig()),
+		zapcore.AddSync(os.Stdout),
+		zap.InfoLevel,
+	)
+}
+
+func getLogLevel(value string) zapcore.LevelEnabler {
+	switch strings.ToLower(value) {
+	case "debug":
+		return zap.DebugLevel
+	case "info":
+		return zap.InfoLevel
+	case "warn":
+		return zap.WarnLevel
+	case "error":
+		return zap.ErrorLevel
+	}
+	return zap.InfoLevel
+}