B.Tech Project On eApproval using Blockchain - Hyperledger Fabric.

1. System UseCase Diagram
2. Architecture
   • 4-Tier App Architecture
   • Fabric Network
   • Chaincode
   • API
   • UI
3. System Security
4. Installation

• The System supports basic functionalities,
  • ADD new Request in StateDB.
  • RETRIEVE Requests stored in StateDB.
  • APPROVE | DECLINE Request stored in StateDB.

1. 4-Tier App Architecture

   • The System has 4 Layers
     • UI
     • API
     • Chaincode
     • Data

2. Fabric Network

   • The Network has 2 ORGs Each with,
     • 1 Peer
     • 1 CA-Peer
   • An Orderer ORG with 1 Peer
   • 2 API Containers

   

   • PORT Mapping

     Container	Port
     peer0.org1.eapproval.com	7051
     peer0.org2.eapproval.com	9051
     couchdb0	5984
     couchdb1	7984
     ca_peerOrg1	7054
     ca_peerOrg2	9054
     orderer.eapproval.com	7050
     API1	8000
     API2	8001
     explorer.eapproval.com	8080

3. Chaincode

   • The Chaincode has the following duties,
     • Create a Request & Store into StateDB.
     • Retrieve Request by querying the StateDB.
     • Approve | Decline a Request Stored in the StateDB.

4. API

   • APIs communicates securely with the chaincode with fabric-node-sdk & also stores the user certificates locally.
   • Both APIs have Endpoints,
     • api/pendingRequests
     • api/approvedRequests
     • api/declinedRequests
     • api/createRequest
     • api/approve
     • api/decline
     • api/query
     • api/invoke
     • api/runRichQuery
     • api/login
     • api/register
   • Both APIs, Returns ORG specific private data.

5. UI

   • UI triggers the API Endpoints and actuates upon the StateDB via Chaincode.
   • UI has 4 sections,
     • Create Request
     • ORG1 Dashboard
     • ORG2 Dashboard
     • Public Board

• The Security is promised via usage of Blockchain.

• Both the DB instances in this case is always in a synchronous state.

• But, if we try to make the states of both the DBs asynchronous by manual changes directly into DB, then while endorsing the Txns via Fabric-SDK on both the peers which involves the changes we made, generates different RW(Read-Write) sets and doesn't get ordered.

• CouchDB-0

  

• CouchDB-1

  

• Policy-Failure

  

• This Project is supported only on Mac & Ubuntu.

• Clone the Repo

  # Don't cd into it
  $ git clone <link> eApproval

• Only Download all the prerequisite NOTE: install node v10 insted of v8, when given option

• Install Fabric Binaries

  $ curl -sSL https://bit.ly/2ysbOFE | bash -s -- 2.0.0 1.4.6 0.4.18

  • This Will also clone fabric-samples in the cwd.

• Copy Fabric Binaries into eApproval

   $ cp ./fabric-samples/bin ./eApproval/bin

• If you have been playing with Docker, kill any stale or active containers.

  $ docker rm -f $(docker ps -aq)
  $ docker rmi -f $(docker images | grep fabcar | awk '{print $3}')

• start the network

  $ make
  

  • Check This for more make commands.

• If manual API starting is required,

  • Before Starting it, set a host route 127.0.0.1 host.docker.internal

     # FOR MAC
     $ sudo nano /private/etc/hosts
     # add:   127.0.0.1		host.docker.internal
     
     # FOR UBUNTU
     $ sudo nano /etc/hosts
     # add:   127.0.0.1		host.docker.internal

  • Then start

    $ cd ./api
    $ MODE=production ./entrypoint.sh