telegraf/plugins/parsers/json/parser.go

296 lines
6.6 KiB
Go

package json
import (
"bytes"
"encoding/json"
"errors"
"fmt"
"log"
"strconv"
"strings"
"time"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/filter"
"github.com/influxdata/telegraf/internal"
"github.com/influxdata/telegraf/metric"
"github.com/tidwall/gjson"
)
var (
utf8BOM = []byte("\xef\xbb\xbf")
ErrWrongType = errors.New("must be an object or an array of objects")
)
type Config struct {
MetricName string
TagKeys []string
NameKey string
StringFields []string
Query string
TimeKey string
TimeFormat string
Timezone string
DefaultTags map[string]string
}
type Parser struct {
metricName string
tagKeys []string
stringFields filter.Filter
nameKey string
query string
timeKey string
timeFormat string
timezone string
defaultTags map[string]string
}
func New(config *Config) (*Parser, error) {
stringFilter, err := filter.Compile(config.StringFields)
if err != nil {
return nil, err
}
return &Parser{
metricName: config.MetricName,
tagKeys: config.TagKeys,
nameKey: config.NameKey,
stringFields: stringFilter,
query: config.Query,
timeKey: config.TimeKey,
timeFormat: config.TimeFormat,
timezone: config.Timezone,
defaultTags: config.DefaultTags,
}, nil
}
func (p *Parser) parseArray(data []interface{}) ([]telegraf.Metric, error) {
results := make([]telegraf.Metric, 0)
for _, item := range data {
switch v := item.(type) {
case map[string]interface{}:
metrics, err := p.parseObject(v)
if err != nil {
return nil, err
}
results = append(results, metrics...)
default:
return nil, ErrWrongType
}
}
return results, nil
}
func (p *Parser) parseObject(data map[string]interface{}) ([]telegraf.Metric, error) {
tags := make(map[string]string)
for k, v := range p.defaultTags {
tags[k] = v
}
f := JSONFlattener{}
err := f.FullFlattenJSON("", data, true, true)
if err != nil {
return nil, err
}
name := p.metricName
//checks if json_name_key is set
if p.nameKey != "" {
switch field := f.Fields[p.nameKey].(type) {
case string:
name = field
}
}
//if time key is specified, set it to nTime
nTime := time.Now().UTC()
if p.timeKey != "" {
if p.timeFormat == "" {
err := fmt.Errorf("use of 'json_time_key' requires 'json_time_format'")
return nil, err
}
if f.Fields[p.timeKey] == nil {
err := fmt.Errorf("JSON time key could not be found")
return nil, err
}
nTime, err = internal.ParseTimestampWithLocation(f.Fields[p.timeKey], p.timeFormat, p.timezone)
if err != nil {
return nil, err
}
delete(f.Fields, p.timeKey)
//if the year is 0, set to current year
if nTime.Year() == 0 {
nTime = nTime.AddDate(time.Now().Year(), 0, 0)
}
}
tags, nFields := p.switchFieldToTag(tags, f.Fields)
metric, err := metric.New(name, tags, nFields, nTime)
if err != nil {
return nil, err
}
return []telegraf.Metric{metric}, nil
}
//will take in field map with strings and bools,
//search for TagKeys that match fieldnames and add them to tags
//will delete any strings/bools that shouldn't be fields
//assumes that any non-numeric values in TagKeys should be displayed as tags
func (p *Parser) switchFieldToTag(tags map[string]string, fields map[string]interface{}) (map[string]string, map[string]interface{}) {
for _, name := range p.tagKeys {
//switch any fields in tagkeys into tags
if fields[name] == nil {
continue
}
switch value := fields[name].(type) {
case string:
tags[name] = value
delete(fields, name)
case bool:
tags[name] = strconv.FormatBool(value)
delete(fields, name)
case float64:
tags[name] = strconv.FormatFloat(value, 'f', -1, 64)
delete(fields, name)
default:
log.Printf("E! [parsers.json] Unrecognized type %T", value)
}
}
//remove any additional string/bool values from fields
for fk := range fields {
switch fields[fk].(type) {
case string, bool:
if p.stringFields != nil && p.stringFields.Match(fk) {
continue
}
delete(fields, fk)
}
}
return tags, fields
}
func (p *Parser) Parse(buf []byte) ([]telegraf.Metric, error) {
if p.query != "" {
result := gjson.GetBytes(buf, p.query)
buf = []byte(result.Raw)
if !result.IsArray() && !result.IsObject() {
err := fmt.Errorf("E! Query path must lead to a JSON object or array of objects, but lead to: %v", result.Type)
return nil, err
}
}
buf = bytes.TrimSpace(buf)
buf = bytes.TrimPrefix(buf, utf8BOM)
if len(buf) == 0 {
return make([]telegraf.Metric, 0), nil
}
var data interface{}
err := json.Unmarshal(buf, &data)
if err != nil {
return nil, err
}
switch v := data.(type) {
case map[string]interface{}:
return p.parseObject(v)
case []interface{}:
return p.parseArray(v)
default:
return nil, ErrWrongType
}
}
func (p *Parser) ParseLine(line string) (telegraf.Metric, error) {
metrics, err := p.Parse([]byte(line + "\n"))
if err != nil {
return nil, err
}
if len(metrics) < 1 {
return nil, fmt.Errorf("can not parse the line: %s, for data format: json ", line)
}
return metrics[0], nil
}
func (p *Parser) SetDefaultTags(tags map[string]string) {
p.defaultTags = tags
}
type JSONFlattener struct {
Fields map[string]interface{}
}
// FlattenJSON flattens nested maps/interfaces into a fields map (ignoring bools and string)
func (f *JSONFlattener) FlattenJSON(
fieldname string,
v interface{}) error {
if f.Fields == nil {
f.Fields = make(map[string]interface{})
}
return f.FullFlattenJSON(fieldname, v, false, false)
}
// FullFlattenJSON flattens nested maps/interfaces into a fields map (including bools and string)
func (f *JSONFlattener) FullFlattenJSON(
fieldname string,
v interface{},
convertString bool,
convertBool bool,
) error {
if f.Fields == nil {
f.Fields = make(map[string]interface{})
}
fieldname = strings.Trim(fieldname, "_")
switch t := v.(type) {
case map[string]interface{}:
for k, v := range t {
err := f.FullFlattenJSON(fieldname+"_"+k+"_", v, convertString, convertBool)
if err != nil {
return err
}
}
case []interface{}:
for i, v := range t {
k := strconv.Itoa(i)
err := f.FullFlattenJSON(fieldname+"_"+k+"_", v, convertString, convertBool)
if err != nil {
return nil
}
}
case float64:
f.Fields[fieldname] = t
case string:
if convertString {
f.Fields[fieldname] = v.(string)
} else {
return nil
}
case bool:
if convertBool {
f.Fields[fieldname] = v.(bool)
} else {
return nil
}
case nil:
return nil
default:
return fmt.Errorf("JSON Flattener: got unexpected type %T with value %v (%s)",
t, t, fieldname)
}
return nil
}