HyperledgerFabric SampleChaincode does not implement shim Chaincode error

Question

I am trying to run this code:

func main() {

lld, _ := shim.LogLevel("DEBUG")
fmt.Println(lld)
logger.SetLevel(lld)
fmt.Println(logger.IsEnabledFor(lld))
err := shim.Start(new(SampleChaincode))
if err != nil {
    logger.Error("Could not start SampleChaincode")
} else {
    logger.Info("SampleChaincode successfully started")
}

}

I am getting the following error:

>  cannot use new(SampleChaincode) (type *SampleChaincode) as type
> shim.Chaincode in argument to shim.Start:
>         *SampleChaincode does not implement shim.Chaincode (wrong type for Init method)
>                 have Init(shim.ChaincodeStubInterface, string, []string) ([]byte, error)
>                 want Init(shim.ChaincodeStubInterface) peer.Response

Answer 1

The reason you are getting this error is because the signature of the function in interface is changed to:

// Chaincode interface must be implemented by all chaincodes. The fabric runs
// the transactions by calling these functions as specified.
type Chaincode interface {
    // Init is called during Instantiate transaction after the chaincode container
    // has been established for the first time, allowing the chaincode to
    // initialize its internal data
    Init(stub ChaincodeStubInterface) pb.Response

    // Invoke is called to update or query the ledger in a proposal transaction.
    // Updated state variables are not committed to the ledger until the
    // transaction is committed.
    Invoke(stub ChaincodeStubInterface) pb.Response
}

Writing a code in the right signature would solve this.