Monitors errors and database with New Relic

api/api.go

@@ -14,6 +14,9 @@ import (
 	"time"
 
 	"github.com/cuducos/go-cnpj"
+	"github.com/cuducos/minha-receita/monitor"
+	"github.com/newrelic/go-agent/v3/integrations/logcontext-v2/logWriter"
+	"github.com/newrelic/go-agent/v3/newrelic"
 )
 
 const cacheMaxAge = time.Hour * 24
@@ -30,26 +33,37 @@ type errorMessage struct {
 	Message string `json:"message"`
 }
 
+type api struct {
+	db          database
+	host        string
+	errorLogger logWriter.LogWriter
+}
+
 // messageResponse takes a text message and a HTTP status, wraps the message into a
 // JSON output and writes it together with the proper headers to a response.
-func messageResponse(w http.ResponseWriter, s int, m string) {
-	w.WriteHeader(s)
+func (app *api) messageResponse(w http.ResponseWriter, s int, m string) {
 	if m == "" {
+		w.WriteHeader(s)
+		if s == http.StatusInternalServerError {
+			app.errorLogger.Write([]byte("Internal server error without error message"))
+		}
 		return
 	}
 
 	b, err := json.Marshal(errorMessage{m})
 	if err != nil {
-		fmt.Fprintf(os.Stderr, "Could not wrap message in JSON: %s", m)
+		w.WriteHeader(http.StatusInternalServerError)
+		app.errorLogger.Write([]byte(fmt.Sprintf("Could not wrap message in JSON: %s", m)))
 		return
 	}
+
+	w.WriteHeader(s)
 	w.Header().Set("Content-type", "application/json")
 	w.Write(b)
-}
 
-type api struct {
-	db   database
-	host string
+	if s == http.StatusInternalServerError {
+		app.errorLogger.Write(b)
+	}
 }
 
 func (app *api) companyHandler(w http.ResponseWriter, r *http.Request) {
@@ -65,7 +79,7 @@ func (app *api) companyHandler(w http.ResponseWriter, r *http.Request) {
 		w.WriteHeader(http.StatusOK)
 		return
 	default:
-		messageResponse(w, http.StatusMethodNotAllowed, "Essa URL aceita apenas o método GET.")
+		app.messageResponse(w, http.StatusMethodNotAllowed, "Essa URL aceita apenas o método GET.")
 		return
 	}
 
@@ -75,13 +89,13 @@ func (app *api) companyHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 	if !cnpj.IsValid(v) {
-		messageResponse(w, http.StatusBadRequest, fmt.Sprintf("CNPJ %s inválido.", cnpj.Mask(v[1:])))
+		app.messageResponse(w, http.StatusBadRequest, fmt.Sprintf("CNPJ %s inválido.", cnpj.Mask(v[1:])))
 		return
 	}
 
 	s, err := app.db.GetCompany(cnpj.Unmask(v))
 	if err != nil {
-		messageResponse(w, http.StatusNotFound, fmt.Sprintf("CNPJ %s não encontrado.", cnpj.Mask(v)))
+		app.messageResponse(w, http.StatusNotFound, fmt.Sprintf("CNPJ %s não encontrado.", cnpj.Mask(v)))
 		return
 	}
 	w.Header().Set("Content-type", "application/json")
@@ -91,25 +105,25 @@ func (app *api) companyHandler(w http.ResponseWriter, r *http.Request) {
 
 func (app *api) updatedHandler(w http.ResponseWriter, r *http.Request) {
 	if r.Method != http.MethodGet {
-		messageResponse(w, http.StatusMethodNotAllowed, "Essa URL aceita apenas o método GET.")
+		app.messageResponse(w, http.StatusMethodNotAllowed, "Essa URL aceita apenas o método GET.")
 		return
 	}
 	s, err := app.db.MetaRead("updated-at")
 	if err != nil {
-		messageResponse(w, http.StatusInternalServerError, "Erro buscando data de atualização.")
+		app.messageResponse(w, http.StatusInternalServerError, "Erro buscando data de atualização.")
 		return
 	}
 	if s == "" {
 		w.WriteHeader(http.StatusInternalServerError)
 		return
 	}
 	w.Header().Set("Cache-Control", cacheControl)
-	messageResponse(w, http.StatusOK, fmt.Sprintf("%s é a data de extração dos dados pela Receita Federal.", s))
+	app.messageResponse(w, http.StatusOK, fmt.Sprintf("%s é a data de extração dos dados pela Receita Federal.", s))
 }
 
 func (app *api) healthHandler(w http.ResponseWriter, r *http.Request) {
 	if r.Method != http.MethodGet {
-		messageResponse(w, http.StatusMethodNotAllowed, "Essa URL aceita apenas o método GET.")
+		app.messageResponse(w, http.StatusMethodNotAllowed, "Essa URL aceita apenas o método GET.")
 		return
 	}
 	w.WriteHeader(http.StatusOK)
@@ -131,12 +145,15 @@ func (app *api) allowedHostWrapper(h func(http.ResponseWriter, *http.Request)) f
 }
 
 // Serve spins up the HTTP server.
-func Serve(db database, p, n string) {
+func Serve(db database, p string, nr *newrelic.Application) {
 	if !strings.HasPrefix(p, ":") {
 		p = ":" + p
 	}
-	nr := newRelicApp(n)
-	app := api{db: db, host: os.Getenv("ALLOWED_HOST")}
+	app := api{
+		db:          db,
+		host:        os.Getenv("ALLOWED_HOST"),
+		errorLogger: logWriter.New(os.Stderr, nr),
+	}
 	for _, r := range []struct {
 		path    string
 		handler func(http.ResponseWriter, *http.Request)
@@ -145,7 +162,7 @@ func Serve(db database, p, n string) {
 		{"/updated", app.updatedHandler},
 		{"/healthz", app.healthHandler},
 	} {
-		http.HandleFunc(newRelicHandle(nr, r.path, app.allowedHostWrapper(r.handler)))
+		http.HandleFunc(monitor.NewRelicHandle(nr, r.path, app.allowedHostWrapper(r.handler)))
 	}
 	log.Output(1, fmt.Sprintf("Serving at http://0.0.0.0%s", p))
 	log.Fatal(http.ListenAndServe(p, nil))

cmd/api.go

@@ -6,6 +6,8 @@ import (
 
 	"github.com/cuducos/minha-receita/api"
 	"github.com/cuducos/minha-receita/db"
+	"github.com/cuducos/minha-receita/monitor"
+	"github.com/newrelic/go-agent/v3/newrelic"
 	"github.com/spf13/cobra"
 )
 
@@ -41,7 +43,17 @@ var apiCmd = &cobra.Command{
 		if err != nil {
 			return err
 		}
-		pg, err := db.NewPostgreSQL(u, postgresSchema)
+		if newRelic == "" {
+			newRelic = os.Getenv("NEW_RELIC_LICENSE_KEY")
+		}
+		var nr *newrelic.Application
+		if newRelic != "" {
+			nr, err = monitor.NewRelicApp(newRelic)
+			if err != nil {
+				return err
+			}
+		}
+		pg, err := db.NewPostgreSQL(u, postgresSchema, nr)
 		if err != nil {
 			return err
 		}
@@ -52,10 +64,7 @@ var apiCmd = &cobra.Command{
 		if port == "" {
 			port = defaultPort
 		}
-		if newRelic == "" {
-			newRelic = os.Getenv("NEW_RELIC_LICENSE_KEY")
-		}
-		api.Serve(&pg, port, newRelic)
+		api.Serve(&pg, port, nr)
 		return nil
 	},
 }

cmd/cmd.go

@@ -66,7 +66,7 @@ var createCmd = &cobra.Command{
 		if err != nil {
 			return err
 		}
-		pg, err := db.NewPostgreSQL(u, postgresSchema)
+		pg, err := db.NewPostgreSQL(u, postgresSchema, nil)
 		if err != nil {
 			return err
 		}
@@ -83,7 +83,7 @@ var dropCmd = &cobra.Command{
 		if err != nil {
 			return err
 		}
-		pg, err := db.NewPostgreSQL(u, postgresSchema)
+		pg, err := db.NewPostgreSQL(u, postgresSchema, nil)
 		if err != nil {
 			return err
 		}

cmd/transform.go

@@ -31,7 +31,7 @@ var transformCmd = &cobra.Command{
 		if err != nil {
 			return err
 		}
-		pg, err := db.NewPostgreSQL(u, postgresSchema)
+		pg, err := db.NewPostgreSQL(u, postgresSchema, nil)
 		if err != nil {
 			return err
 		}

db/postgres.go

@@ -13,6 +13,8 @@ import (
 
 	"github.com/jackc/pgx/v5"
 	"github.com/jackc/pgx/v5/pgxpool"
+	"github.com/newrelic/go-agent/v3/integrations/nrpgx5"
+	"github.com/newrelic/go-agent/v3/newrelic"
 )
 
 const (
@@ -31,6 +33,7 @@ var sql embed.FS
 // PostgreSQL database interface.
 type PostgreSQL struct {
 	pool                  *pgxpool.Pool
+	newRelic              *newrelic.Application
 	uri                   string
 	schema                string
 	sql                   map[string]string
@@ -125,7 +128,15 @@ func (p *PostgreSQL) GetCompany(id string) (string, error) {
 	if err != nil {
 		return "", fmt.Errorf("error converting cnpj %s to integer: %w", id, err)
 	}
-	rows, err := p.pool.Query(context.Background(), p.sql["get"], n)
+
+	ctx := context.Background()
+	if p.newRelic != nil {
+		txn := p.newRelic.StartTransaction("GetCompany")
+		ctx = newrelic.NewContext(ctx, txn)
+		defer txn.End()
+	}
+
+	rows, err := p.pool.Query(ctx, p.sql["get"], n)
 	if err != nil {
 		return "", fmt.Errorf("error looking for cnpj %d: %w", n, err)
 	}
@@ -179,8 +190,15 @@ func (p *PostgreSQL) MetaRead(k string) (string, error) {
 }
 
 // NewPostgreSQL creates a new PostgreSQL connection and ping it to make sure it works.
-func NewPostgreSQL(uri, schema string) (PostgreSQL, error) {
-	conn, err := pgxpool.New(context.Background(), uri)
+func NewPostgreSQL(uri, schema string, nr *newrelic.Application) (PostgreSQL, error) {
+	cfg, err := pgxpool.ParseConfig(uri)
+	if err != nil {
+		return PostgreSQL{}, fmt.Errorf("could not create database config: %w", err)
+	}
+	if nr != nil {
+		cfg.ConnConfig.Tracer = nrpgx5.NewTracer()
+	}
+	conn, err := pgxpool.NewWithConfig(context.Background(), cfg)
 	if err != nil {
 		return PostgreSQL{}, fmt.Errorf("could not connect to the database: %w", err)
 	}

db/postgres_test.go

@@ -14,7 +14,7 @@ func TestPostgresDB(t *testing.T) {
 		t.Errorf("expected a posgres uri at TEST_DATABASE_URL, found nothing")
 		return
 	}
-	pg, err := NewPostgreSQL(u, "public")
+	pg, err := NewPostgreSQL(u, "public", nil)
 	if err != nil {
 		t.Errorf("expected no error connecting to postgres, got %s", err)
 		return

go.mod

@@ -8,6 +8,8 @@ require (
 	github.com/dgraph-io/badger/v4 v4.2.0
 	github.com/jackc/pgx/v5 v5.5.0
 	github.com/newrelic/go-agent/v3 v3.27.0
+	github.com/newrelic/go-agent/v3/integrations/logcontext-v2/logWriter v1.0.1
+	github.com/newrelic/go-agent/v3/integrations/nrpgx5 v1.2.0
 	github.com/schollz/progressbar/v3 v3.14.1
 	github.com/spf13/cobra v1.8.0
 	golang.org/x/text v0.14.0
@@ -26,11 +28,15 @@ require (
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/flatbuffers v23.3.3+incompatible // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/jackc/pgmock v0.0.0-20210724152146-4ad1a8207f65 // indirect
 	github.com/jackc/pgpassfile v1.0.0 // indirect
+	github.com/jackc/pgproto3/v2 v2.3.2 // indirect
 	github.com/jackc/pgservicefile v0.0.0-20221227161230-091c0ba34f0a // indirect
+	github.com/jackc/pgx/v4 v4.18.1 // indirect
 	github.com/jackc/puddle/v2 v2.2.1 // indirect
 	github.com/klauspost/compress v1.16.4 // indirect
 	github.com/mitchellh/colorstring v0.0.0-20190213212951-d06e56a500db // indirect
+	github.com/newrelic/go-agent/v3/integrations/logcontext-v2/nrwriter v1.0.0 // indirect
 	github.com/pkg/errors v0.9.1 // indirect
 	github.com/rivo/uniseg v0.4.4 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect