Discussion Forum Middleware Error Codes

Introduction

This document describes how to construct Error codes for all operations?

Background

Jira Issues

https://project-sunbird.atlassian.net/browse/SB-21578

Examples Of Error code

PFT_CCRT10  >> PBK_CCRT10  >> DMW_CCRT10  >> NBB_CCRT10 

TraceId: 1234 
Error happened at NodeBB end. 
NBB_CCRT10 << NBB_CCRT10  << NBB_CCRT10 << NBB_CCRT10 

===> Servies: 
Discussion Middleware service -> DMW 
NodeBB Sercie -> NBB 

===> Operations: 
Category create - CCRT 
Topic create    - TCRT 
Group create    - GCRT 
Usr create      - UCRT 

===> ERROR CODES: 
01 - Category creation failed because of reason 1? 
02 - Category create failed because of reason 2? 
03 - Category update failed because of reason 1? 
04 - Category update failed because of reason 2? 
... 
DMW_CCRT01 
NBB_GCRT{error_code}

Problem Statement:

How to assign specific error code to api?

Solution:

API	Unique Operation Name	Operation Name	Error Number	Error Description	Error Code
FORUM API's
/forum/v2/read	FRED	DMW_FRED	01	Forum read failed because plugin not enabled.	DMW_FRED01
/forum/v2/create	FCRT	DMW_FCRT	02	Forum create failed because plugin not enabled.	DMW_FCRT02
Tags API
/tags	TRED	DMW_TRED	03	Tags read failed	DMW_TRED03
USER DETAILS API's
/user/:userslug	URED	DMW_URED	04	User details read failed	DMW_URED04
/user/:userslug/upvoted	UUVR	DMW_URED	05	User up vote post details read failed	DMW_URED05
/user/:userslug/downvoted	UDVR	DMW_URED	06	User down vote post details read failed	DMW_URED06
/user/:userslug/bookmarks	UBMR	DMW_URED	07	User saved post details read failed	DMW_URED07
/user/v1/create	UCRT	DMW_UCRT	08	Create user failed	DMW_UCRT08
CATEGORY API's
/category/:category_id/:slug	CDTL	DMW_CRED	09	Category details read failed.	DMW_CRED09
/category/:cid	CRED	DMW_CRED
/categories	CLST	DMW_CRED	10	Access list of categories failed.	DMW_CRED10
/v2/categories	CCRT	DMW_CCRT	11	Create category failed	DMW_CCRT11
/v2/categories/:cid(PUT)	CUDT	DMW_CUDT	12	Update category failed	DMW_CUDT12
/v2/categories/:cid(DELETE)	CDEL	DMW_CDEL	13	Delete category failed	DMW_CDEL13
TOPICS API's
/unread	TUNR	DMW_TRED	14	Access unread topics failed	DMW_TRED14
/recent	TRCT	DMW_TRED	15	Access recent topics failed.	DMW_TRED15
/topic/:topic_id/:slug	TDTL	DMW_TRED	16	Access topic details failed	DMW_TRED16
/v2/topics	TCRT	DMW_TCRT	17	Create topic failed	DMW_TCRT17
/v2/topics/:tid(POST)	RCRT	DMW_RCRT	18	Add reply failed	DMW_RCRT18
/v2/topics/:tid(PUT)	TUDT	DMW_TUDT	19	Update topics/reply failed	DMW_TUDT19
/v2/topics/:tid(DELETE)	TDEL	DMW_TDEL	20	Delete topic/reply failed	DMW_TDEL20
POST API's
/post/pid/:pid	PRED	DWM_PRED	21	Access post details failed	DWM_PRED21
/v2/posts/:pid(POST)	PCRT	DMW_PCRT	22	Create post failed	DMW_PCRT22
/v2/posts/:pid(DELETE)	PDEL	DWM_PDEL	23	Delete post failed	DWM_PDEL23
/v2/posts/:pid/vote(POST)	PVOT	DMW_PCRT	24	Adding vote to a post failed	DMW_PCRT24
/v2/posts/:pid/vote(DELETE)	PVDL	DMW_PCRT	25	Deleting vote failed	DMW_PCRT25
/v2/posts/:pid/bookmark(POST)	PSVE	DMW_PCRT	26	Bookmark post failed	DMW_PCRT26
/v2/posts/:pid/bookmark(DELETE)	PUSVE	DMW_PCRT	27	Delete bookmark failed	DMW_PCRT27

Challenges:

We can not tract nodebb api errors, because we are only accessing nodebb api, we not doing code changes.
We can track only discussion forum Errors and Portal Errors. But In Middleware and Portal backend we are doing proxy calls only, so we can tract only code issues instead of actual api issues.

How to get proper error code for a particular api in discussion middleware?

To get the proper error code for a particular api, we are maintain a json object like below

{
'/discussions/forum/v2/read': {
                              'errorMsg': "Forum read api failed because of plugin not enabled",
                              'err': "DMW_FRED01"
                              },
'/discussions/forum/v2/creat': {
                                'errorMsg': "Forum creat api failed because of plugin not enabled",
                                'err': "DMW_FCRT02"
                                },
'/discussions/v2/topic': {
                          'errorMsg': "Create topic  failed",
                          'err': "DMW_TCRT17"
                          },
.....
.....
.....
}

in Proxy object we are mapping the error code like below

**** Import Error Json file here as errorCodes *****
app.post(`${BASE_REPORT_URL}/forum/v2/read`, proxyObject());
app.post(`${BASE_REPORT_URL}/forum/v2/create`, proxyObject());
app.post(`${BASE_REPORT_URL}/v2/topics`, proxyObject());

function proxyObject() {
  return proxy(nodebbServiceUrl, {
    proxyReqOptDecorator: proxyUtils.decorateRequestHeaders(),
    proxyReqPathResolver: function (req) {
      let urlParam = req.originalUrl.replace('/discussion', '');
      let query = require('url').parse(req.url).query;
      if (query) {
        return require('url').parse(nodebbServiceUrl+ urlParam + '?' + query).path
      } else {
		const incomingUrl = req.protocol + '://' + req.get('host') + req.originalUrl;
        const proxyUrl = require('url').parse(nodebbServiceUrl + urlParam);
        return proxyUrl.path;
      }
    },
    userResDecorator: (proxyRes, proxyResData, req, res) => {
      try {
        const data = (proxyResData.toString('utf8'));
        if (proxyRes.statusCode === 404 ) {
          return data;
        } else {
          return proxyUtils.handleSessionExpiry(proxyRes, proxyResData, req, res, data);
        }
      } catch (err) {
      
      ***
      Here is mapping happned
      const errorObj = errorCodes[req.originalUrl];
      {
        "id": "discussion.forum.middleware",
        "ver": "1.0",
        "ts": "2020-11-25T07:18:09.945Z",
        "params": {
            "resmsgid": "5f36c090-2eee-11eb-80ed-6bb70096c082",
            "msgid": "req.headers['x-requester-id']",
            "status": "failed",
            "err": errorObj.err,
            "errmsg": errorObj .errorMsg
        }
    }
      ***
        return proxyUtils.handleSessionExpiry(proxyRes, proxyResData, req, res);
      }
    }
  })
}