Added client to send hits to Pirsch and short demo.

.gitignore

@@ -0,0 +1 @@
+.idea/

README.md

@@ -1,2 +1,10 @@
-# go-sdk
-Golang Client SDK for Pirsch.
+# Pirsch Golang SDK
+
+[![GoDoc](https://godoc.org/github.com/pirsch-analytics/go-sdk?status.svg)](https://godoc.org/github.com/pirsch-analytics/go-sdk)
+<a href="https://discord.gg/fAYm4Cz"><img src="https://img.shields.io/discord/739184135649886288?logo=discord" alt="Chat on Discord"></a>
+
+This is the official Golang client SDK for Pirsch. For details, please check out our [documentation](https://docs.pirsch.io/).
+
+## License
+
+MIT

client.go

@@ -0,0 +1,156 @@
+package pirsch
+
+import (
+	"bytes"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"sync"
+	"time"
+)
+
+const (
+	defaultBaseURL         = "https://api.pirsch.io"
+	authenticationEndpoint = "/api/v1/token"
+	hitEndpoint            = "/api/v1/hit"
+)
+
+// Client is a client used to access the Pirsch API.
+type Client struct {
+	baseURL      string
+	clientID     string
+	clientSecret string
+	hostname     string
+	accessToken  string
+	expiresAt    time.Time
+	m            sync.Mutex
+}
+
+// ClientConfig is used to configure the Client.
+type ClientConfig struct {
+	// BaseURL is optional and can be used to configure a different host for the API.
+	// This is usually left empty in production environments.
+	BaseURL string
+}
+
+// NewClient creates a new client for given client ID, client secret, hostname, and optional configuration.
+// A new client ID and secret can be generated on the Pirsch dashboard.
+// The hostname must match the hostname you configured on the Pirsch dashboard (e.g. example.com).
+func NewClient(clientID, clientSecret, hostname string, config *ClientConfig) *Client {
+	baseURL := defaultBaseURL
+
+	if config != nil && config.BaseURL != "" {
+		baseURL = config.BaseURL
+	}
+
+	return &Client{
+		baseURL:      baseURL,
+		clientID:     clientID,
+		clientSecret: clientSecret,
+		hostname:     hostname,
+	}
+}
+
+// Hit sends a page hit to Pirsch for given http.Request.
+func (client *Client) Hit(r *http.Request) error {
+	return client.performPost(client.baseURL+hitEndpoint, &Hit{
+		Hostname:       client.hostname,
+		URL:            r.URL.String(),
+		IP:             r.RemoteAddr,
+		CFConnectingIP: r.Header.Get("CF-Connecting-IP"),
+		XForwardedFor:  r.Header.Get("X-Forwarded-For"),
+		Forwarded:      r.Header.Get("Forwarded"),
+		XRealIP:        r.Header.Get("X-Real-IP"),
+		UserAgent:      r.Header.Get("User-Agent"),
+		AcceptLanguage: r.Header.Get("Accept-Language"),
+		Referrer:       r.Header.Get("Referrer"),
+	})
+}
+
+func (client *Client) refreshToken() error {
+	body := struct {
+		ClientId     string `json:"client_id"`
+		ClientSecret string `json:"client_secret"`
+	}{
+		client.clientID,
+		client.clientSecret,
+	}
+	bodyJson, err := json.Marshal(&body)
+
+	if err != nil {
+		return err
+	}
+
+	c := http.Client{}
+	resp, err := c.Post(client.baseURL+authenticationEndpoint, "application/json", bytes.NewBuffer(bodyJson))
+
+	if err != nil {
+		return err
+	}
+
+	respJson := struct {
+		AccessToken string    `json:"access_token"`
+		ExpiresAt   time.Time `json:"expires_at"`
+	}{}
+
+	decoder := json.NewDecoder(resp.Body)
+
+	if err := decoder.Decode(&respJson); err != nil {
+		return err
+	}
+
+	client.m.Lock()
+	defer client.m.Unlock()
+	client.accessToken = respJson.AccessToken
+	client.expiresAt = respJson.ExpiresAt
+	return nil
+}
+
+func (client *Client) performPost(url string, body interface{}) error {
+	reqBody, err := json.Marshal(body)
+
+	if err != nil {
+		return err
+	}
+
+	req, err := http.NewRequest("POST", url, bytes.NewReader(reqBody))
+
+	if err != nil {
+		return err
+	}
+
+	client.setRequestHeaders(req)
+	c := http.Client{}
+	resp, err := c.Do(req)
+
+	if err != nil {
+		return err
+	}
+
+	// refresh access token and retry on 401
+	if resp.StatusCode == http.StatusUnauthorized {
+		if err := client.refreshToken(); err != nil {
+			return err
+		}
+
+		client.setRequestHeaders(req)
+		resp, err = c.Do(req)
+
+		if err != nil {
+			return err
+		}
+	}
+
+	if resp.StatusCode != http.StatusOK {
+		body, _ := ioutil.ReadAll(resp.Body)
+		return errors.New(fmt.Sprintf("%s: received status code %d on request: %s", url, resp.StatusCode, string(body)))
+	}
+
+	return nil
+}
+
+func (client *Client) setRequestHeaders(req *http.Request) {
+	req.Header.Set("Authorization", "Bearer "+client.accessToken)
+}

demo/main.go

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+package main
+
+import (
+	"github.com/pirsch-analytics/go-sdk"
+	"log"
+	"net/http"
+)
+
+const (
+	// Client ID, secret, and hostname for testing.
+	// Replace them with your own.
+	clientID     = "i9OulOrSI0b5EBNQbb8vg5zfEg2zhQ5q"
+	clientSecret = "FgwcclcvpTK75oqmbc6UxmJTXX3iCK8JcqPvz7ozzJzouc39KLEeriXQy45Myq92"
+	hostname     = "first.page"
+)
+
+func main() {
+	log.Println("Visit http://localhost:1414")
+
+	// Create a client for Pirsch.
+	client := pirsch.NewClient(clientID, clientSecret, hostname, &pirsch.ClientConfig{
+		BaseURL: "http://localhost.com:9999",
+	})
+
+	// Add a handler to serve a page.
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		// To analyze traffic, send page hits to Pirsch.
+		// You can control what gets send to Pirsch, in case the page was not found for example.
+		if r.URL.Path == "/" {
+			if err := client.Hit(r); err != nil {
+				log.Println(err)
+			}
+		}
+
+		w.Write([]byte("<h1>Hello from Pirsch!</h1>"))
+	})
+	http.ListenAndServe(":1414", nil)
+}

types.go

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+package pirsch
+
+// Hit are the parameters to send a page hit to Pirsch.
+type Hit struct {
+	Hostname       string
+	URL            string `json:"url"`
+	IP             string `json:"ip"`
+	CFConnectingIP string `json:"cf_connecting_ip"`
+	XForwardedFor  string `json:"x_forwarded_for"`
+	Forwarded      string `json:"forwarded"`
+	XRealIP        string `json:"x_real_ip"`
+	UserAgent      string `json:"user_agent"`
+	AcceptLanguage string `json:"accept_language"`
+	Referrer       string `json:"referrer"`
+}