Initial commit

README.md

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+# OPENTSDB metrics push GO client
+
+Client has 2 options to send metrics:
+ - Enqueue metrics, send when batchSize collected and flush buffer. Use Push to force send current buffer.
+ - Send single Metric immediately.
+
+*Important*
+
+Do not forger invoke `Close` on service down, to send unfilled buffer
+
+## Usage
+
+Import:
+
+`go get github.com/n10ty/opentsdb-go-push`
+
+Example:
+
+```go
+func main() {
+    client := opentsdb.NewClient("http://localhost:4242", opentsdb.WithBatchSize(30))
+	err := client.Enqueue(opentsdb.Metric{
+		Timestamp: time.Now().Truncate(time.Minute).Unix(),
+		Metric:    "http_response_time",
+		Value:     39.3,
+		Tags: map[string]string{
+			"server": "server1",
+		},
+	})
+	if err != nil {
+		//...
+	}
+	client.Push()
+}
+```

client.go

@@ -0,0 +1,153 @@
+package opentsdb
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
+)
+
+const defaultBatchSize = 20
+
+// Client has 2 options to send metrics:
+// - Enqueue metrics, send when batchSize collected and flush buffer. Use Push to force send current buffer.
+// - Send single Metric immediately.
+type Client struct {
+	host      string
+	authUser  string
+	authPass  string
+	buffer    []Metric
+	batchSize int
+}
+
+type Metric struct {
+	Timestamp int64             `json:"timestamp"`
+	Metric    string            `json:"metric"`
+	Value     any               `json:"value"`
+	Tags      map[string]string `json:"tags"`
+}
+
+type config struct {
+	authUsername string
+	authPassword string
+	batchSize    int
+}
+
+func NewClient(host string, options ...Option) *Client {
+	config := &config{
+		authUsername: "",
+		authPassword: "",
+		batchSize:    defaultBatchSize,
+	}
+	for _, o := range options {
+		o(config)
+	}
+
+	return &Client{
+		host:      host,
+		authUser:  config.authUsername,
+		authPass:  config.authPassword,
+		batchSize: config.batchSize,
+	}
+}
+
+// Enqueue send metric to a buffer. Metrics are sent when buffer reaches batchSize number.
+func (c *Client) Enqueue(metric Metric) error {
+	if metric.Tags == nil {
+		return errors.New("tags can not be nil")
+	}
+	c.buffer = append(c.buffer, metric)
+	if len(c.buffer) >= c.batchSize {
+		err := c.send(c.buffer)
+		c.buffer = []Metric{}
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+// Send single Metric immediately
+func (c *Client) Send(metric Metric) error {
+	if metric.Tags == nil {
+		return errors.New("tags can not be nil")
+	}
+	return c.send([]Metric{metric})
+}
+
+func (c *Client) send(metric []Metric) error {
+	url := fmt.Sprintf("%s/api/put", c.host)
+	m, err := json.Marshal(metric)
+	if err != nil {
+		return err
+	}
+	req, err := http.NewRequest(http.MethodPut, url, body(m))
+	if err != nil {
+		return err
+	}
+
+	if c.authUser != "" {
+		req.SetBasicAuth(c.authUser, c.authPass)
+	}
+	req.Header.Add("Content-Type", "application/json")
+	res, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return err
+	}
+	if res.StatusCode >= 400 {
+		b, err := ioutil.ReadAll(res.Body)
+		if err != nil {
+			return err
+		}
+		return fmt.Errorf("%s: %s", res.Status, string(b))
+	}
+
+	return nil
+}
+
+// Push buffer and clean it
+func (c *Client) Push() error {
+	if len(c.buffer) == 0 {
+		return nil
+	}
+	err := c.send(c.buffer)
+	c.buffer = []Metric{}
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+// Close should be used on service down to prevent an unfilled buffer to be gone
+func (c *Client) Close() error {
+	return c.send(c.buffer)
+}
+
+func body(buf []byte) io.Reader {
+	return bytes.NewBuffer(buf)
+}
+
+type Option func(*config) error
+
+// WithAuth setup BasicAuth username and password to use in request
+func WithAuth(username, password string) Option {
+	return func(c *config) error {
+		c.authUsername = username
+		c.authPassword = password
+		return nil
+	}
+}
+
+// WithBatchSize change default number of buffer size to push
+func WithBatchSize(n int) Option {
+	return func(c *config) error {
+		if n < 1 || n > 1024 {
+			return errors.New("batch size should be between 1 and 1024")
+		}
+		c.batchSize = n
+		return nil
+	}
+}

go.mod

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+module github.com/n10ty/opentsdb-go-push
+
+go 1.18