package couchdb import ( "encoding/json" "errors" "fmt" "github.com/influxdata/telegraf" "github.com/influxdata/telegraf/registry/inputs" "net/http" "reflect" "strings" "sync" "time" ) // 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")) } var tr = &http.Transport{ ResponseHeaderTimeout: time.Duration(3 * time.Second), } var client = &http.Client{ Transport: tr, Timeout: time.Duration(4 * time.Second), } func (c *CouchDB) fetchAndInsertData(accumulator telegraf.Accumulator, host string) error { response, error := client.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{} }) }