IT-SDK-Hyperledger-Fabric-Dev

Resources Allowed for Certification

Hyperledger Fabric

• https://hyperledger-fabric.readthedocs.io/en/release-2.2/ (Documentation)
• https://hyperledger-fabric.readthedocs.io/en/release-2.2/command_ref.html (Command Reference)
• https://hyperledger.github.io/fabric-chaincode-node/release-2.2/api/index.html (Fabric-Contract API)
• https://hyperledger.github.io/fabric-sdk-node/release-2.2/index.html (Fabric-Application API)
• https://wiki.hyperledger.org/display/fabric/Hyperledger+Fabric (WIKI)

Node.js / JavaScript

• https://nodejs.org/docs/latest-v12.x/api/ (Node.js)
• https://developer.mozilla.org/en-US/docs/Web/JavaScript (MDN)

Begriffe

• Ref: https://hyperledger-fabric.readthedocs.io/en/latest/ledger/ledger.html#the-ledger
• Actor: Is an Participants like peers, users, orderers.
• Identity: Every actor has an identity certificate.
• Leger: Record all state transitions, result of chaincode invocations "transactions". One Leger per Channel. Ledger consists of (World-State/Blockchain)
• Blockchain: is a transaction log/history that records all the changes/modifications that have resulted in the current world-state. Is immutable (unchangeable).
• World-State: is a database that represent the current values of ledger states.
• Smart-Contract: Software-Program that defines business logic.
• Chaincode: A Smart-Contract packaged in a Chaincode then deployed to blockchain-network.
• Client-Application: interact with blockchain network on behalf of useres.
• Wallet: contains a sset of user identities to connects to a channel
• Gateway: manges the network interactions on behalf of application.
• Transaction:
• Wallet: contains a set of user identities. With these identities user connects to a channel and access a leger.

Components

• Ref: https://hyperledger-fabric.readthedocs.io/en/release-2.2/peers/peers.html
• Blockchain-Network:
• Channel: Each channel has a completely separate ledger. This means a completely separate blockchain, and completely separate world-states.
• CA (Certificate authorities): Issue identities by generating public and private key forming key-pair that can be used to prove an identity.
• MSP (Memberahip Service Provider): contains a list of permissioned identities (public keys).
• Peer: Is a Nodes that host a ledger and a Smart-Contract/Chaincode. Chaincodes generate transaction and access the leger.
• Orderer:

Chaincode Deployment/Upgrade

• Package the chaincode.
• Install the chaincode package.
• Approval the chaincode definition.
• Commit the chaincode defintion to a channel.

Commands

peer lifecycle chaincode package $PACKAGE_NAME.tar.gz --path $PATH_SOURCECODE --lang $LANG --label $LABEL
peer lifecycle chaincode install $PACKAGE_NAME.tat.gz
peer lifecycle chaincode queryinstalled
peer lifecycle chaincode approveformyorg --orderer $ORDERER --channelID $CHANNEL_ID --name $CHAINCOD_NAME --version 1.0 --package-id $PACKAGE_ID --sequence 1
peer lifecycle chaincode checkcommitreadiness --channelID $CHANNEL_ID --name $CHAINCOD_NAME --version 1.0 --sequence 1 --output json
peer lifecycle chaincode commit --orderer $ORDERER --channelID $CHANNEL_ID --name $CHAINCODE_NAME --version 1.0 --sequence 1 --peerAddresses $PEER_ADDRESSE
peer lifecycle chaincode querycommitted --channelID $CHANNEL_ID --name $CHAINCODE_NAME
peer chaincode invoke/query --orderer $ORDERER --channelID $CHANNEL_ID --name $CHAINCODE_NAME --ctor $MASSAGE
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./network.sh deployCC -ccn $NAME -ccl javascript -ccp $PATH -ccv 1.0 -ccs 1 -cci init

Dev-Chaincode

ctx.stub.getState(key);
ctx.stub.deleteState(key);
ctx.stub.putState(key,value);
ctx.stub.getStateByRange(keyFrom, keyTo);
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ctx.stub.createCompositeKey(objType, [key]);
ctx.stub.splitCompositeKey(key);
ctx.stub.getStateByPartialCompositeKey(objType, []);
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ctx.stub.getQueryResult(queryString);
ctx.stub.getHistoryForKey(compositeKey);
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ctx.clientIdentity.getMSPID();
ctx.clientIdentity.getID();
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ctx.stub.invokeChaincode(chaincode, args, channel);

Dev-Application

• Interaction with blockchain-network (Channel & Chaincode) through a Gateway. (fabric-network)
• CA-Actions: Register user, enroll user, revoke a user. (fabric-ca-client)
• Wallet-Types: FileSystemWallet, InMemoryWallet, CouchDBWallet
• Gateway: Connection profile/configuration

Wallet

await Wallets.newFileSystemWallet('./wallet');
await wallet.put(identityLabel, identity);
await wallet.get(identityLabel);
await wallet.remove(identityLabel);
await wallet.list();

Gateway

const gateway = new Gateway();
await gateway.connect(connectionProfile, connectionOptions);
const network = await gateway.getNetwork('mychannel');
const contract = network.getContract('balance_transfer');
const response = await contract.submitTransaction(functionName, ...chaincodeArgs);
gateway.disconnect();

Enroll-User

### enrollUser.js ####
const ca = new FabricCAServices(connectionProfile['certificateAuthorities'][`ca.${orgName}`].url);
let enrollmentRequest = {
      enrollmentID: enrollmentID,
      enrollmentSecret: enrollmentSecret,
      attr_reqs: enrollmentAttributes
    };
const enrollment = await ca.enroll(enrollmentRequest);
identity = {
  credentials: {
    certificate: enrollment.certificate,
    privateKey: enrollment.key.toBytes(),
  },
  mspId: `${orgNameCapitalized}MSP`,
  type: 'X.509',
};
await wallet.put(identityLabel, identity);

Register-User

### registerUser.js ###
const ca = new FabricCAServices(connectionProfile['certificateAuthorities'][`ca.${orgName}`].url);
const provider = wallet.getProviderRegistry().getProvider(registrarIdentity.type);
const registrarUser = await provider.getUserContext(registrarIdentity, registrarLabel);
let registerRequest = {
      enrollmentID: enrollmentID,
      enrollmentSecret: optional.secret || "",
      role: 'client',
      attrs: optional.attrs || []
    };
const secret = await ca.register(registerRequest, registrarUser);

NPM-Commands

npm init -y
npm install
node addToWallet.js
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node enrollUser.js 'CAAdmin@org1.example.com' admin adminpw
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node registerUser.js 'CAAdmin@org1.example.com' 'User@org1.example.com' '{"secret": "userpw"}'
node enrollUser.js 'User@org1.example.com' 'User@org1.example.com' userpw