dead-letter-queue

A tiny go package to manage HTTP requests with dead letter management/retry. Based on go-redis.

Installation

go get -u github.com/ranjanrak/dead-letter-queue

• Usage
• Request
  • Adding message
  • Delete message from the request queue
  • Delete message from the dead letter queue
  • Clear request queue
  • Clear deadletter queue
• Execute queue
  • Execute request queue
  • Execute deadletter queue
• Fetch message response status
• Sample response

Usage

package main

import (
    "log"
    "net/http"
    "net/url"

    deadletterqueue "github.com/ranjanrak/dead-letter-queue"
)
func main() {
    // Create new HTTP request queue instance
    httpQueue := deadletterqueue.New(deadletterqueue.ClientParam{
		RedisAddr: "",
		RedisPasw: "",
		Ctx:       nil,
		QueueName: "",
		DeadHTTP:  []int{400, 403, 429, 500, 502},
    })

    // Add post params
    postParam := url.Values{}
    postParam.Add("exchange", "NSE")
    postParam.Add("tradingsymbol", "TCS")
    postParam.Add("transaction_type", "BUY")
    postParam.Add("quantity", "1")
    postParam.Add("product", "CNC")
    postParam.Add("order_type", "MARKET")
    postParam.Add("validity", "DAY")

    // Add request header
    var headers http.Header = map[string][]string{}
    headers.Add("x-kite-version", "3")
    headers.Add("authorization", "token api_key:access_token")
    headers.Add("content-type", "application/x-www-form-urlencoded")

    // Request message
    reqMsgOrd := deadletterqueue.InputMsg{
        Name:      "Place TCS Order",
        Url:       "https://api.kite.trade/orders/regular",
        ReqMethod: "POST",
        PostParam: postParam,
        Headers:   headers,
    }

    // worker that adds message to redis queue
    err := httpQueue.AddMessage(reqMsgOrd)
    if err != nil {
        log.Fatalf("Error adding msg in the request queue : %v", err)
    }

    // worker that executes http request queues
    httpQueue.ExecuteQueue()

    // worker that executes dead letter http queues
    httpQueue.ExecuteDeadQueue()
}

Request

Request represents an HTTP request with all parameters.

Adding message

Adding an HTTP message to the request queue with all parameters.

// Add request header
var headers http.Header = map[string][]string{}
headers.Add("x-kite-version", "3")
headers.Add("authorization", "token api_key:access_token")

// Request message
queueMsg := deadletterqueue.InputMsg{
    Name:      "Fetch order book",
    Url:       "https://api.kite.trade/orders",
    ReqMethod: "GET",
    PostParam: nil,
    Headers:   headers,
}
err := httpQueue.AddMessage(queueMsg)
if err != nil {
    log.Fatalf("Error adding msg in the request queue : %v", err)
}

Delete message from the request queue

Delete request message available in the queue before it's execution with the input message Name.

err := httpQueue.DeleteReqMsg("Place TCS Order")
if err != nil {
    log.Fatalf("Error removing msg from the request msg queue : %v", err)
}

Delete message from the dead letter queue

Delete message by the input message Name from the Deadletter queue.

err := httpQueue.DeleteDeadMsg("Place TCS Order")
if err != nil {
    log.Fatalf("Error removing msg from the deadletter queue : %v", err)
}

Clear request queue

Clear complete request message queue.

err := httpQueue.ClearReqQueue()
if err != nil {
    log.Fatalf("Error clearing the request queue : %v", err)
}

Clear deadletter queue

Clear complete deadletter message queue.

err := httpQueue.ClearDeadQueue()
if err != nil {
    log.Fatalf("Error clearing the deadletter queue : %v", err)
}

Execute/run message queue

Execute request queue or dead letter queue(i.e failed HTTP request).

Execute request queue

Execute HTTP requests in the request queue

httpQueue.ExecuteQueue()

Execute deadletter queue

Execute failed HTTP request message i.e dead letter queue.

httpQueue.ExecuteDeadQueue()

Fetch message response status

Fetch response body of an given message name, post it's execution.

status, err := httpQueue.MessageStatus("Place TCS Order")
if err != nil {
    log.Fatalf("Error %v", err)
}
log.Printf("Response status %v: ", status)

Sample responses

Response status : {"status":"success","data":{"order_id":"220627001805439"}}

Response status : {"status":"error",
"message":"Your order price is lower than the current [lower circuit limit]",
"data":null,"error_type":"InputException"}

Sample response

httpQueue.GetQueue("ReqQueue"): Lists all the available messages in the http queue

[{"Name":"Place TCS Order","Url":"https://api.kite.trade/orders/regular",
"ReqMethod":"POST","PostParam":{"exchange":"NSE","order_type":"MARKET",
"product":"CNC","quantity":1,"tradingsymbol":"TCS","transaction_type":"BUY",
"validity":"DAY"},"Headers":{"authorization":"token abcd123:efgh1234",
"content-type":"application/x-www-form-urlencoded","x-kite-version":3}},
{"Name":"Post session token","Url":"https://api.kite.trade/session/token",
"ReqMethod":"POST","PostParam":{"api_key":"api_key","checksum":"checksum",
"request_token":"request_token"},"Headers":{"x-kite-version":3}},
..]