etcd store example

README.md

@@ -245,6 +245,8 @@ func main() {
 }
 ```
 
+#### 2.3.7 Example Use Etcd as store
+[captcha with etcd database as store](captcha_with_etcd_exmaple.md)
 
 ## 3. 🎨🎨🎨 Customization
 You can customize your captcha display image by implementing [interface driver](interface_driver.go) 

captcha_with_etcd_exmaple.md

@@ -0,0 +1,111 @@
+# Captcha with Etcd as store example
+
+
+## captcha/captcha_etcd.go
+```go
+package captcha
+
+import (
+	"context"
+	"github.com/mojocn/base64Captcha"
+	"go.etcd.io/etcd/clientv3"
+	"image/color"
+	"library/database/etcd"
+	"time"
+)
+
+//CaptchaEtcd base64 captcha with etcd
+type CaptchaEtcd struct {
+	*base64Captcha.DriverString
+	store *etcd.Client
+}
+
+//NewClientEtcd constructor
+func NewClientEtcd(height, width int, store *etcd.Client) *CaptchaEtcd {
+	d := base64Captcha.NewDriverString(height, width, 0, 0, 4, "%#=qwe23456789rtyupasdfghjkzxcvbnm", &color.RGBA{0, 0, 0, 0}, []string{"wqy-microhei.ttc"})
+	cli := &CaptchaEtcd{store: store}
+	cli.DriverString = d
+	return cli
+}
+
+const (
+	captchaPrefix  = "captcha:"
+	requestTimeout = time.Second
+)
+
+//GenerateIdAndImage create image
+func (c *CaptchaEtcd) GenerateIdAndImage() (id, b64s, ans string, err error) {
+	id, content, answer := c.GenerateIdQuestionAnswer()
+	item, err := c.DrawCaptcha(content)
+	if err != nil {
+		return "", "", "", err
+	}
+	//expire in 120s
+	grantResp, err := c.store.Grant(context.TODO(), 120)
+	if err != nil {
+		return "", "", "", err
+	}
+	ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
+	_, err = c.store.Put(ctx, captchaPrefix+id, answer, clientv3.WithLease(grantResp.ID))
+	cancel()
+	if err != nil {
+		return "", "", "", err
+	}
+	b64s = item.EncodeB64string()
+	return id, b64s, answer, nil
+}
+
+//Verify check captcha answer
+func (c *CaptchaEtcd) Verify(id, answer string) (match bool, err error) {
+	ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
+	key := captchaPrefix + id
+	resp, err := c.store.Get(ctx, key)
+	cancel()
+	if err != nil {
+		return false, err
+	}
+
+	for _, ev := range resp.Kvs {
+		if string(ev.Value) == answer {
+			return true, err
+		}
+	}
+	return false, err
+}
+
+```
+
+## captcha\captcha_etcd_test.go
+
+```go
+package captcha
+
+import (
+	"library/database/etcd"
+	"testing"
+)
+
+func TestCaptchaEtcd_Verify(t *testing.T) {
+	store, err := etcd.New([]string{"10.217.56.146:2379"}, requestTimeout, "", "", 0, 0, "", "", "")
+	if err != nil {
+		t.Error("etcd new failed ", err)
+		return
+	}
+	cap := NewClientEtcd(80, 240, store)
+	id, _, ans, err := cap.GenerateIdAndImage()
+	if err != nil {
+		t.Error("captcha generate failed ", err)
+		return
+	}
+	ok, err := cap.Verify(id, ans)
+	if err != nil {
+		t.Error("clear false ", err)
+		return
+	}
+	if !ok {
+		t.Error("verify failed")
+		return
+	}
+
+}
+```