Code Challenge @IBM Developer Day

Challenge

Interest Rate while creating a new asset should be increased by 2 when creates a entry in blockchain. Interface should also show the same.

For example, while creating a new asset if you provide interest rate as 10 then it should save as 12.

Chaincode

~/securitization_blockchain/chaincode/src has lib.go, securitization.go, read_ledger.go and write_ledger.go.

Find out

• which file you need to modify
• which function
• what code changes are required

To compile chaincode locally

echo $GOROOT
/usr/local/go

echo $GOPATH

# Set GOPATH
export GOPATH=/home/student/fabric1.2

# Navigate to chincode directory ~/securitization_blockchain/chaincode/src
go build        ## It will be helpful to check for any errors in chaincode
OR 
go build -o <output binary name>

Install Chaincode on your channel

IBP Dashboard -> Channels -> Choose your channel -> Switch to Chaincode -> Install Chaincode -> Choose Peer -> Install Chaincode

• Provide same Chaincode ID as before.
• Chaincode Version should be different say v2.
• Choose all chaincode files.
• Click on Submit.

Update your chaincode

Choose Update action for your installed chaincode as shown.

Configure Application

• Clean up the previous connection related details.

  cd ~/securitization_blockchain/sc-ui
  rm -f chaincode_info.json
  rm -f connection_profile.json
  rm -rf hfc-key-store
  

• Re-launch your application.

• Configure HF Client - with new version of chaincode.

• The previous entries will be shown on Application as-is.

• Now create a new asset and verify your updated chaincode.

Code changes to be made

Original Code

	asset.InterestRate = args[2]

Updated Code

	interest_rate, _ := strconv.ParseFloat(args[2], 32)
	interest_rate = interest_rate + 0.02
	asset.InterestRate = strconv.FormatFloat(interest_rate, 'f', -1, 32)