Golang Development Utilities

Utilities for golang developments on Conflux blockchain, especially for backend service.

Module	Description
Alert	Send notification message to dingtalk.
API	REST API utilities based on gin.
Config	Initialize all modules.
HTTP	Provides common used middlewares.
Log	Based on logrus and integrated with Alert.
Metrics	To monitor system runtime.
Rate Limit	Utilities to limit request rate.
Store	Provides utilities to initialize database.
Viper	To fix some issues of original viper.

Alert

Before sending any message to dingtalk, client should initialize dingtalk robot when setup program.

Initialize programmatically:

alert.InitDingTalk(config *DingTalkConfig, tags []string)
alert.SendDingTalkTextMessage(level, brief, detail string)

Or, initialize from configuration file, which is recommended:

alert.MustInitFromViper()

Moreover, alert could be integrated with log module, so as to send messages to dingtalk when warning or error logs occurred.

API

This module provides common HTTP responses along with standard errors in JSON format.

Uniform JSON message in HTTP response body:

type BusinessError struct {
	Code    int         `json:"code"`
	Message string      `json:"message"`
	Data    interface{} `json:"data"`
}

Code 0 indicates success, and Data is an object indicates the return value of REST API. Code with non-zero value indicates any error occurred, please refer to the Message and Data fields for more details. There are some pre-defined errors as below:

• 1: Invalid parameter, see Data for detailed error.
• 2: Internal server error, see Data for detailed error.
• 3: Too many requests, see Data for detailed error.

To distinguish backend service error and gateway error, we only use 200 and 600 as HTTP response status code:

• 200: success, or known business error, e.g. entity not found.
• 600: unexpected system error, e.g. database error, io error.

We recommend to initialize REST API from configuration file. Client only requires to provide a factory to setup controllers.

// Setup controllers.
factory := func(router *gin.Engine) {
    router.GET("url", api.Wrap(controller))
}

// Start REST API server in a separate goroutine.
go api.MustServeFromViper(factory)

Config

Initialize all modules at the entry point of program, including viper, log, metrics and alert.

config.MustInit(viperEnvPrefix string)

The viperEnvPrefix is used to overwrite configurations from environment. E.g. if the viperEnvPrefix is FOO, then client could set environment as below to overwrite config alert.dingTalk.secret:

FOO_ALERT_DINGTALK_SECRET='dsafsadf'

You could follow the example config.yaml under config folder to setup your own configuration file. Generally, you could only overwrite configurations if the default value not suitable.

HTTP

Provides utilities to hook middlewares to HTTP handler, e.g. remote address, API key and rate limit.

Log

We recommend to initialize log module from configuration file, and allow to send dingtalk messages when warning or error messages occurred.

Metrics

We recommend to initialize metrics module from configuration file. Client could also configure influxdb to report metrics periodically. See MetricsConfig for more details.

Rate Limit

Provides basic rate limit algorithms, including fixed window, token bucket, along with utilities for HTTP middleware.

Note, rate limit middleware depends on the HTTP middleware RealIP.

Store

We recommend to initialize store module from configuration file.

config := mysql.MustNewConfigFromViper()
db := config.MustOpenOrCreate(tables ...interface{})

Viper

Fixes issues when unmarshal configurations from environment. A simple way to load configuration from file is as below:

viper.MustUnmarshalKey(key string, valPtr interface{}, resolver ...ValueResolver)

// E.g. load `foo` config from file.
var config FooConfig
viper.MustUnmarshalKey("foo", &config)