package influxdb import ( "compress/gzip" "context" "crypto/tls" "encoding/json" "fmt" "io" "log" "net/http" "net/url" "path" "strings" "time" "github.com/influxdata/telegraf" "github.com/influxdata/telegraf/plugins/serializers/influx" ) type APIErrorType int const ( _ APIErrorType = iota DatabaseNotFound ) const ( defaultRequestTimeout = time.Second * 5 defaultDatabase = "telegraf" defaultUserAgent = "telegraf" errStringDatabaseNotFound = "database not found" errStringHintedHandoffNotEmpty = "hinted handoff queue not empty" errStringPartialWrite = "partial write" errStringPointsBeyondRP = "points beyond retention policy" errStringUnableToParse = "unable to parse" ) var ( // Escape an identifier in InfluxQL. escapeIdentifier = strings.NewReplacer( "\n", `\n`, `\`, `\\`, `"`, `\"`, ) ) // APIError is an error reported by the InfluxDB server type APIError struct { StatusCode int Title string Description string Type APIErrorType } func (e APIError) Error() string { if e.Description != "" { return fmt.Sprintf("%s: %s", e.Title, e.Description) } return e.Title } // QueryResponse is the response body from the /query endpoint type QueryResponse struct { Results []QueryResult `json:"results"` } type QueryResult struct { Err string `json:"error,omitempty"` } func (r QueryResponse) Error() string { if len(r.Results) > 0 { return r.Results[0].Err } return "" } // WriteResponse is the response body from the /write endpoint type WriteResponse struct { Err string `json:"error,omitempty"` } func (r WriteResponse) Error() string { return r.Err } type HTTPConfig struct { URL *url.URL UserAgent string Timeout time.Duration Username string Password string TLSConfig *tls.Config Proxy *url.URL Headers map[string]string ContentEncoding string Database string RetentionPolicy string Consistency string Serializer *influx.Serializer } type httpClient struct { WriteURL string QueryURL string ContentEncoding string Timeout time.Duration Username string Password string Headers map[string]string client *http.Client serializer *influx.Serializer url *url.URL database string } func NewHTTPClient(config *HTTPConfig) (*httpClient, error) { if config.URL == nil { return nil, ErrMissingURL } database := config.Database if database == "" { database = defaultDatabase } timeout := config.Timeout if timeout == 0 { timeout = defaultRequestTimeout } userAgent := config.UserAgent if userAgent == "" { userAgent = defaultUserAgent } var headers = make(map[string]string, len(config.Headers)+1) headers["User-Agent"] = userAgent for k, v := range config.Headers { headers[k] = v } var proxy func(*http.Request) (*url.URL, error) if config.Proxy != nil { proxy = http.ProxyURL(config.Proxy) } else { proxy = http.ProxyFromEnvironment } serializer := config.Serializer if serializer == nil { serializer = influx.NewSerializer() } writeURL := makeWriteURL( config.URL, database, config.RetentionPolicy, config.Consistency) queryURL := makeQueryURL(config.URL) client := &httpClient{ serializer: serializer, client: &http.Client{ Timeout: timeout, Transport: &http.Transport{ Proxy: proxy, TLSClientConfig: config.TLSConfig, }, }, database: database, url: config.URL, WriteURL: writeURL, QueryURL: queryURL, ContentEncoding: config.ContentEncoding, Timeout: timeout, Username: config.Username, Password: config.Password, Headers: headers, } return client, nil } // URL returns the origin URL that this client connects too. func (c *httpClient) URL() string { return c.url.String() } // URL returns the database that this client connects too. func (c *httpClient) Database() string { return c.database } // CreateDatabase attemps to create a new database in the InfluxDB server. // Note that some names are not allowed by the server, notably those with // non-printable characters or slashes. func (c *httpClient) CreateDatabase(ctx context.Context) error { query := fmt.Sprintf(`CREATE DATABASE "%s"`, escapeIdentifier.Replace(c.database)) req, err := c.makeQueryRequest(query) resp, err := c.client.Do(req.WithContext(ctx)) if err != nil { return err } defer resp.Body.Close() queryResp := &QueryResponse{} dec := json.NewDecoder(resp.Body) err = dec.Decode(queryResp) if err != nil { if resp.StatusCode == 200 { return nil } return &APIError{ StatusCode: resp.StatusCode, Title: resp.Status, } } // Even with a 200 response there can be an error if resp.StatusCode == http.StatusOK && queryResp.Error() == "" { return nil } return &APIError{ StatusCode: resp.StatusCode, Title: resp.Status, Description: queryResp.Error(), } } // Write sends the metrics to InfluxDB func (c *httpClient) Write(ctx context.Context, metrics []telegraf.Metric) error { var err error reader := influx.NewReader(metrics, c.serializer) req, err := c.makeWriteRequest(reader) if err != nil { return err } resp, err := c.client.Do(req.WithContext(ctx)) if err != nil { return err } defer resp.Body.Close() if resp.StatusCode == http.StatusNoContent { return nil } writeResp := &WriteResponse{} dec := json.NewDecoder(resp.Body) var desc string err = dec.Decode(writeResp) if err == nil { desc = writeResp.Err } if strings.Contains(desc, errStringDatabaseNotFound) { return &APIError{ StatusCode: resp.StatusCode, Title: resp.Status, Description: desc, Type: DatabaseNotFound, } } // This "error" is an informational message about the state of the // InfluxDB cluster. if strings.Contains(desc, errStringHintedHandoffNotEmpty) { return nil } // Points beyond retention policy is returned when points are immediately // discarded for being older than the retention policy. Usually this not // a cause for concern and we don't want to retry. if strings.Contains(desc, errStringPointsBeyondRP) { log.Printf("W! [outputs.influxdb]: when writing to [%s]: received error %v", c.URL(), desc) return nil } // Other partial write errors, such as "field type conflict", are not // correctable at this point and so the point is dropped instead of // retrying. if strings.Contains(desc, errStringPartialWrite) { log.Printf("E! [outputs.influxdb]: when writing to [%s]: received error %v; discarding points", c.URL(), desc) return nil } // This error indicates a bug in either Telegraf line protocol // serialization, retries would not be successful. if strings.Contains(desc, errStringUnableToParse) { log.Printf("E! [outputs.influxdb]: when writing to [%s]: received error %v; discarding points", c.URL(), desc) return nil } return &APIError{ StatusCode: resp.StatusCode, Title: resp.Status, Description: desc, } } func (c *httpClient) makeQueryRequest(query string) (*http.Request, error) { params := url.Values{} params.Set("q", query) form := strings.NewReader(params.Encode()) req, err := http.NewRequest("POST", c.QueryURL, form) if err != nil { return nil, err } req.Header.Set("Content-Type", "application/x-www-form-urlencoded") c.addHeaders(req) return req, nil } func (c *httpClient) makeWriteRequest(body io.Reader) (*http.Request, error) { var err error if c.ContentEncoding == "gzip" { body, err = compressWithGzip(body) if err != nil { return nil, err } } req, err := http.NewRequest("POST", c.WriteURL, body) if err != nil { return nil, err } req.Header.Set("Content-Type", "text/plain; charset=utf-8") c.addHeaders(req) if c.ContentEncoding == "gzip" { req.Header.Set("Content-Encoding", "gzip") } return req, nil } func compressWithGzip(data io.Reader) (io.Reader, error) { pr, pw := io.Pipe() gw := gzip.NewWriter(pw) var err error go func() { _, err = io.Copy(gw, data) gw.Close() pw.Close() }() return pr, err } func (c *httpClient) addHeaders(req *http.Request) { if c.Username != "" || c.Password != "" { req.SetBasicAuth(c.Username, c.Password) } for header, value := range c.Headers { req.Header.Set(header, value) } } func makeWriteURL(loc *url.URL, db, rp, consistency string) string { params := url.Values{} params.Set("db", db) if rp != "" { params.Set("rp", rp) } if consistency != "one" && consistency != "" { params.Set("consistency", consistency) } u := *loc u.Path = path.Join(u.Path, "write") u.RawQuery = params.Encode() return u.String() } func makeQueryURL(loc *url.URL) string { u := *loc u.Path = path.Join(u.Path, "query") return u.String() }