[chore][pkg/stanza] Cleanup syslog parser operator files (#32118)

Contributes to #32058

pkg/stanza/operator/parser/syslog/config.go

@@ -0,0 +1,109 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package syslog // import "github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator/parser/syslog"
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+	"time"
+
+	"go.uber.org/zap"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/entry"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/stanza/operator/helper"
+)
+
+const (
+	operatorType = "syslog_parser"
+
+	RFC3164 = "rfc3164"
+	RFC5424 = "rfc5424"
+
+	NULTrailer = "NUL"
+	LFTrailer  = "LF"
+)
+
+func init() {
+	operator.Register(operatorType, func() operator.Builder { return NewConfig() })
+}
+
+// NewConfig creates a new syslog parser config with default values
+func NewConfig() *Config {
+	return NewConfigWithID(operatorType)
+}
+
+// NewConfigWithID creates a new syslog parser config with default values
+func NewConfigWithID(operatorID string) *Config {
+	return &Config{
+		ParserConfig: helper.NewParserConfig(operatorID, operatorType),
+	}
+}
+
+// Config is the configuration of a syslog parser operator.
+type Config struct {
+	helper.ParserConfig `mapstructure:",squash"`
+	BaseConfig          `mapstructure:",squash"`
+}
+
+// BaseConfig is the detailed configuration of a syslog parser.
+type BaseConfig struct {
+	Protocol                     string  `mapstructure:"protocol,omitempty"`
+	Location                     string  `mapstructure:"location,omitempty"`
+	EnableOctetCounting          bool    `mapstructure:"enable_octet_counting,omitempty"`
+	AllowSkipPriHeader           bool    `mapstructure:"allow_skip_pri_header,omitempty"`
+	NonTransparentFramingTrailer *string `mapstructure:"non_transparent_framing_trailer,omitempty"`
+}
+
+// Build will build a JSON parser operator.
+func (c Config) Build(logger *zap.SugaredLogger) (operator.Operator, error) {
+	if c.ParserConfig.TimeParser == nil {
+		parseFromField := entry.NewAttributeField("timestamp")
+		c.ParserConfig.TimeParser = &helper.TimeParser{
+			ParseFrom:  &parseFromField,
+			LayoutType: helper.NativeKey,
+		}
+	}
+
+	parserOperator, err := c.ParserConfig.Build(logger)
+	if err != nil {
+		return nil, err
+	}
+
+	proto := strings.ToLower(c.Protocol)
+
+	switch {
+	case proto == "":
+		return nil, fmt.Errorf("missing field 'protocol'")
+	case proto != RFC5424 && (c.NonTransparentFramingTrailer != nil || c.EnableOctetCounting):
+		return nil, errors.New("octet_counting and non_transparent_framing are only compatible with protocol rfc5424")
+	case proto == RFC5424 && (c.NonTransparentFramingTrailer != nil && c.EnableOctetCounting):
+		return nil, errors.New("only one of octet_counting or non_transparent_framing can be enabled")
+	case proto == RFC5424 && c.NonTransparentFramingTrailer != nil:
+		if *c.NonTransparentFramingTrailer != NULTrailer && *c.NonTransparentFramingTrailer != LFTrailer {
+			return nil, fmt.Errorf("invalid non_transparent_framing_trailer '%s'. Must be either 'LF' or 'NUL'", *c.NonTransparentFramingTrailer)
+		}
+	case proto != RFC5424 && proto != RFC3164:
+		return nil, fmt.Errorf("unsupported protocol version: %s", proto)
+	}
+
+	if c.Location == "" {
+		c.Location = "UTC"
+	}
+
+	location, err := time.LoadLocation(c.Location)
+	if err != nil {
+		return nil, fmt.Errorf("failed to load location %s: %w", c.Location, err)
+	}
+
+	return &Parser{
+		ParserOperator:               parserOperator,
+		protocol:                     proto,
+		location:                     location,
+		enableOctetCounting:          c.EnableOctetCounting,
+		allowSkipPriHeader:           c.AllowSkipPriHeader,
+		nonTransparentFramingTrailer: c.NonTransparentFramingTrailer,
+	}, nil
+}