add MongoDB,Redis,Kafka retry mechanism (#518)

pkg/common/mw/gin.go

@@ -31,6 +31,7 @@ import (
 	"github.com/OpenIMSDK/Open-IM-Server/pkg/errs"
 )
 
+// CorsHandler gin cross-domain configuration.
 func CorsHandler() gin.HandlerFunc {
 	return func(c *gin.Context) {
 		c.Writer.Header().Set("Access-Control-Allow-Origin", "*")
@@ -39,19 +40,19 @@ func CorsHandler() gin.HandlerFunc {
 		c.Header(
 			"Access-Control-Expose-Headers",
 			"Content-Length, Access-Control-Allow-Origin, Access-Control-Allow-Headers,Cache-Control,Content-Language,Content-Type,Expires,Last-Modified,Pragma,FooBar",
-		) // 跨域关键设置 让浏览器可以解析
+		) // Cross-domain key settings allow browsers to resolve.
 		c.Header(
 			"Access-Control-Max-Age",
 			"172800",
-		) // 缓存请求信息 单位为秒
+		) // Cache request information in seconds.
 		c.Header(
 			"Access-Control-Allow-Credentials",
 			"false",
-		) //  跨域请求是否需要带cookie信息 默认设置为true
+		) //  Whether cross-domain requests need to carry cookie information, the default setting is true.
 		c.Header(
 			"content-type",
 			"application/json",
-		) // 设置返回格式是json
+		) // Set the return format to json.
 		//Release all option pre-requests
 		if c.Request.Method == http.MethodOptions {
 			c.JSON(http.StatusOK, "Options Request!")