telegraf/plugins/inputs/couchdb/couchdb.go

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package couchdb
import (
"encoding/json"
"errors"
"fmt"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/inputs"
"net/http"
"reflect"
"strings"
"sync"
)
// Schema:
type metaData struct {
Description string `json:"description"`
Current float64 `json:"current"`
Sum float64 `json:"sum"`
Mean float64 `json:"mean"`
Stddev float64 `json:"stddev"`
Min float64 `json:"min"`
Max float64 `json:"max"`
}
type Stats struct {
Couchdb struct {
AuthCacheMisses metaData `json:"auth_cache_misses"`
DatabaseWrites metaData `json:"database_writes"`
OpenDatabases metaData `json:"open_databases"`
AuthCacheHits metaData `json:"auth_cache_hits"`
RequestTime metaData `json:"request_time"`
DatabaseReads metaData `json:"database_reads"`
OpenOsFiles metaData `json:"open_os_files"`
} `json:"couchdb"`
HttpdRequestMethods struct {
Put metaData `json:"PUT"`
Get metaData `json:"GET"`
Copy metaData `json:"COPY"`
Delete metaData `json:"DELETE"`
Post metaData `json:"POST"`
Head metaData `json:"HEAD"`
} `json:"httpd_request_methods"`
HttpdStatusCodes struct {
Status200 metaData `json:"200"`
Status201 metaData `json:"201"`
Status202 metaData `json:"202"`
Status301 metaData `json:"301"`
Status304 metaData `json:"304"`
Status400 metaData `json:"400"`
Status401 metaData `json:"401"`
Status403 metaData `json:"403"`
Status404 metaData `json:"404"`
Status405 metaData `json:"405"`
Status409 metaData `json:"409"`
Status412 metaData `json:"412"`
Status500 metaData `json:"500"`
} `json:"httpd_status_codes"`
Httpd struct {
ClientsRequestingChanges metaData `json:"clients_requesting_changes"`
TemporaryViewReads metaData `json:"temporary_view_reads"`
Requests metaData `json:"requests"`
BulkRequests metaData `json:"bulk_requests"`
ViewReads metaData `json:"view_reads"`
} `json:"httpd"`
}
type CouchDB struct {
HOSTs []string `toml:"hosts"`
}
func (*CouchDB) Description() string {
return "Read CouchDB Stats from one or more servers"
}
func (*CouchDB) SampleConfig() string {
return `
# Works with CouchDB stats endpoints out of the box
# Multiple HOSTs from which to read CouchDB stats:
hosts = ["http://localhost:8086/_stats"]
`
}
func (c *CouchDB) Gather(accumulator telegraf.Accumulator) error {
errorChannel := make(chan error, len(c.HOSTs))
var wg sync.WaitGroup
for _, u := range c.HOSTs {
wg.Add(1)
go func(host string) {
defer wg.Done()
if err := c.fetchAndInsertData(accumulator, host); err != nil {
errorChannel <- fmt.Errorf("[host=%s]: %s", host, err)
}
}(u)
}
wg.Wait()
close(errorChannel)
// If there weren't any errors, we can return nil now.
if len(errorChannel) == 0 {
return nil
}
// There were errors, so join them all together as one big error.
errorStrings := make([]string, 0, len(errorChannel))
for err := range errorChannel {
errorStrings = append(errorStrings, err.Error())
}
return errors.New(strings.Join(errorStrings, "\n"))
}
func (c *CouchDB) fetchAndInsertData(accumulator telegraf.Accumulator, host string) error {
response, error := http.Get(host)
if error != nil {
return error
}
defer response.Body.Close()
var stats Stats
decoder := json.NewDecoder(response.Body)
decoder.Decode(&stats)
fields := map[string]interface{}{}
// CouchDB meta stats:
c.MapCopy(fields, c.generateFields("couchdb_auth_cache_misses", stats.Couchdb.AuthCacheMisses))
c.MapCopy(fields, c.generateFields("couchdb_database_writes", stats.Couchdb.DatabaseWrites))
c.MapCopy(fields, c.generateFields("couchdb_open_databases", stats.Couchdb.OpenDatabases))
c.MapCopy(fields, c.generateFields("couchdb_auth_cache_hits", stats.Couchdb.AuthCacheHits))
c.MapCopy(fields, c.generateFields("couchdb_request_time", stats.Couchdb.RequestTime))
c.MapCopy(fields, c.generateFields("couchdb_database_reads", stats.Couchdb.DatabaseReads))
c.MapCopy(fields, c.generateFields("couchdb_open_os_files", stats.Couchdb.OpenOsFiles))
// http request methods stats:
c.MapCopy(fields, c.generateFields("httpd_request_methods_put", stats.HttpdRequestMethods.Put))
c.MapCopy(fields, c.generateFields("httpd_request_methods_get", stats.HttpdRequestMethods.Get))
c.MapCopy(fields, c.generateFields("httpd_request_methods_copy", stats.HttpdRequestMethods.Copy))
c.MapCopy(fields, c.generateFields("httpd_request_methods_delete", stats.HttpdRequestMethods.Delete))
c.MapCopy(fields, c.generateFields("httpd_request_methods_post", stats.HttpdRequestMethods.Post))
c.MapCopy(fields, c.generateFields("httpd_request_methods_head", stats.HttpdRequestMethods.Head))
// status code stats:
c.MapCopy(fields, c.generateFields("httpd_status_codes_200", stats.HttpdStatusCodes.Status200))
c.MapCopy(fields, c.generateFields("httpd_status_codes_201", stats.HttpdStatusCodes.Status201))
c.MapCopy(fields, c.generateFields("httpd_status_codes_202", stats.HttpdStatusCodes.Status202))
c.MapCopy(fields, c.generateFields("httpd_status_codes_301", stats.HttpdStatusCodes.Status301))
c.MapCopy(fields, c.generateFields("httpd_status_codes_304", stats.HttpdStatusCodes.Status304))
c.MapCopy(fields, c.generateFields("httpd_status_codes_400", stats.HttpdStatusCodes.Status400))
c.MapCopy(fields, c.generateFields("httpd_status_codes_401", stats.HttpdStatusCodes.Status401))
c.MapCopy(fields, c.generateFields("httpd_status_codes_403", stats.HttpdStatusCodes.Status403))
c.MapCopy(fields, c.generateFields("httpd_status_codes_404", stats.HttpdStatusCodes.Status404))
c.MapCopy(fields, c.generateFields("httpd_status_codes_405", stats.HttpdStatusCodes.Status405))
c.MapCopy(fields, c.generateFields("httpd_status_codes_409", stats.HttpdStatusCodes.Status409))
c.MapCopy(fields, c.generateFields("httpd_status_codes_412", stats.HttpdStatusCodes.Status412))
c.MapCopy(fields, c.generateFields("httpd_status_codes_500", stats.HttpdStatusCodes.Status500))
// httpd stats:
c.MapCopy(fields, c.generateFields("httpd_clients_requesting_changes", stats.Httpd.ClientsRequestingChanges))
c.MapCopy(fields, c.generateFields("httpd_temporary_view_reads", stats.Httpd.TemporaryViewReads))
c.MapCopy(fields, c.generateFields("httpd_requests", stats.Httpd.Requests))
c.MapCopy(fields, c.generateFields("httpd_bulk_requests", stats.Httpd.BulkRequests))
c.MapCopy(fields, c.generateFields("httpd_view_reads", stats.Httpd.ViewReads))
tags := map[string]string{
"server": host,
}
accumulator.AddFields("couchdb", fields, tags)
return nil
}
func (*CouchDB) MapCopy(dst, src interface{}) {
dv, sv := reflect.ValueOf(dst), reflect.ValueOf(src)
for _, k := range sv.MapKeys() {
dv.SetMapIndex(k, sv.MapIndex(k))
}
}
func (*CouchDB) safeCheck(value interface{}) interface{} {
if value == nil {
return 0.0
}
return value
}
func (c *CouchDB) generateFields(prefix string, obj metaData) map[string]interface{} {
fields := map[string]interface{}{
prefix + "_current": c.safeCheck(obj.Current),
prefix + "_sum": c.safeCheck(obj.Sum),
prefix + "_mean": c.safeCheck(obj.Mean),
prefix + "_stddev": c.safeCheck(obj.Stddev),
prefix + "_min": c.safeCheck(obj.Min),
prefix + "_max": c.safeCheck(obj.Max),
}
return fields
}
func init() {
inputs.Add("couchdb", func() telegraf.Input {
return &CouchDB{}
})
}