Chaincode as external service

Steps to write a chaincode compatible for running as an external service

Golang:

• Import the shim package and create the ChaincodeServer struct from the shim package.

• The ChaincodeServer struct takes the following values:

  • CC: It takes contractapi.ContractInterface which was created using contractapi.NewChaincode() function.

  • CCID: It takes the chaincode package id. This can be accessed from the CORE_CHAINCODE_ID environment variable.

  • Address: Chaincode server address to expose the chaincode. This can be accessed from the CORE_CHAINCODE_ADDRESS environment variable.

  • TLSProps: It accepts the struct value of shim.TLSProperties

• Then call the start function from the created ChaincodeServer struct value (server.Start())

Eg: https://github.com/spydra-tech/external-chaincode-reference/blob/main/go/main.go

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Javascript:

1. If chaincode is written using contract api:

In package.json, modify the value of scripts.start section to ”fabric-chaincode-node server”

Eg: https://github.com/spydra-tech/external-chaincode-reference/blob/main/javascript/using-contract-api/package.json

2. If chaincode is written using fabric-shim:

• In the file where the chaincode is initialised / started, create the shim.server by passing ccid and address which are taken from the runtime environment variables CORE_CHAINCODE_ID and CHAINCODE_SERVER_ADDRESS

• Then call the start function from the created shim.server object (server.start())

Eg: https://github.com/spydra-tech/external-chaincode-reference/blob/main/javascript/using-shim-api/cc.js