Address some linter warnings, report Close() errors on Parquet files

cmd/pqlogd/main.go

@@ -97,7 +97,7 @@ func main() {
 		<-sigCh
 		log.Printf("received termination signal, exiting...")
 		ctx, cancel := context.WithTimeout(context.Background(), 30*time.Second)
-		httpSrv.Shutdown(ctx)
+		httpSrv.Shutdown(ctx) // nolint:errcheck
 		cancel()
 		httpSrv.Close()
 	}()

cmd/pqlogd/mtls.go

@@ -14,7 +14,7 @@ var (
 	tlsCA   = flag.String("tls-ca", "", "TLS CA certificate")
 )
 
-// tlsConfig returns a tls.Config built from command-line options.
+// buildTLSConfig returns a tls.Config built from command-line options.
 func buildTLSConfig() (*tls.Config, error) {
 	if *tlsCert == "" || *tlsKey == "" {
 		return nil, nil

http/ingest.go

@@ -146,7 +146,7 @@ func (s *IngestServer) DebugHandler(w http.ResponseWriter, req *http.Request) {
 	s.mx.Unlock()
 
 	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(out)
+	_ = json.NewEncoder(w).Encode(out)
 }
 
 func (s *IngestServer) SchemaHandler(w http.ResponseWriter, req *http.Request) {
@@ -158,5 +158,5 @@ func (s *IngestServer) SchemaHandler(w http.ResponseWriter, req *http.Request) {
 	s.mx.Unlock()
 
 	w.Header().Set("Content-Type", "application/json")
-	json.NewEncoder(w).Encode(out)
+	_ = json.NewEncoder(w).Encode(out)
 }

http/query.go

@@ -70,7 +70,7 @@ func (q *QueryServer) runQuery(ctx context.Context, w io.Writer, query string) e
 	if err != nil {
 		return fmt.Errorf("failed to create transaction: %w", err)
 	}
-	defer tx.Rollback()
+	defer tx.Rollback() // nolint:errcheck
 
 	remoteGlob := q.src.ParquetURI(q.glob)
 	_, err = tx.Exec(fmt.Sprintf("CREATE VIEW %s AS SELECT * FROM read_parquet('%s', union_by_name=true)", table, remoteGlob))
@@ -79,6 +79,7 @@ func (q *QueryServer) runQuery(ctx context.Context, w io.Writer, query string) e
 	}
 	defer func() {
 		// Well, ok, we have the Rollback() but.
+		// nolint:errcheck
 		tx.Exec(fmt.Sprintf("DROP VIEW %s", table))
 	}()
 

integrationtest/integrationtest.go

@@ -77,7 +77,7 @@ func randomRecord(rec *testRecord) {
 		rec.A0 = rand.Int63n(3)
 		rec.A1 = rand.Float64() * 128.0
 	} else {
-		rec.Message = fmt.Sprintf("this is a test message, quite boring")
+		rec.Message = "this is a test message, quite boring"
 	}
 }
 

schema/schema.go

@@ -153,9 +153,9 @@ func NewGuesser() *Guesser {
 }
 
 type serializableGuesser struct {
-	Columns        map[string]int
-	Errors         map[string]string
-	VersionCounter int64
+	Columns        map[string]int    `json:"columns"`
+	Errors         map[string]string `json:"errors"`
+	VersionCounter int64             `json:"version_counter"`
 }
 
 func (sg *serializableGuesser) Guesser() *Guesser {
@@ -208,7 +208,7 @@ type Schema struct {
 	upcast  map[string]upcastFunc
 }
 
-// GetSchema returns the best possible version of a schema given our
+// NewSchema returns the best possible version of a schema given our
 // current data type guesses.
 func (g *Guesser) NewSchema() *Schema {
 	cols := make(map[string]Type)

writer/writer.go

@@ -15,7 +15,7 @@ import (
 type Writer interface {
 	Reopen(*schema.ParquetSchemaHandler) error
 	Write(any) error
-	Close()
+	Close() error
 }
 
 // The ParquetWriter writes a sequence of sequentially numbered
@@ -41,9 +41,10 @@ func (w *ParquetWriter) Write(obj any) error {
 	return w.pw.Write(obj)
 }
 
-func (w *ParquetWriter) Close() {
+func (w *ParquetWriter) Close() error {
+	var err error
 	if w.pw != nil {
-		w.pw.WriteStop()
+		err = w.pw.WriteStop()
 		w.pw = nil
 	}
 	if w.lw != nil {
@@ -51,16 +52,20 @@ func (w *ParquetWriter) Close() {
 		w.lw = nil
 	}
 	if w.renameTo != "" {
-		if err := w.src.Rename(w.renameTo+".tmp", w.renameTo); err != nil {
-			log.Printf("warning: could not finalize parquet file %s: %v", w.renameTo, err)
+		// Only rename the file if WriteStop was successful.
+		if err == nil {
+			err = w.src.Rename(w.renameTo+".tmp", w.renameTo)
 		}
 		w.renameTo = ""
 	}
+	return err
 }
 
 // (Re)open the output with a new schema.
 func (w *ParquetWriter) Reopen(schemaHandler *schema.ParquetSchemaHandler) error {
-	w.Close()
+	if err := w.Close(); err != nil {
+		log.Printf("error finalizing Parquet file: %v", err)
+	}
 
 	path, err := w.pg.Next()
 	if err != nil {