Add fabcar external service sample (#136)

Add sample which can be used with the builder scripts described in
the "Chaincode as an external service" documentation

Signed-off-by: James Taylor <jamest@uk.ibm.com>

chaincode/fabcar/external/.dockerignore

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+chaincode.env*
+*.json
+*.md
+*.tar.gz
+*.tgz

chaincode/fabcar/external/.gitignore

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+chaincode.env
+connection.json
+*.tar.gz
+*.tgz

chaincode/fabcar/external/Dockerfile

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+# Copyright IBM Corp. All Rights Reserved.
+#
+# SPDX-License-Identifier: Apache-2.0
+
+ARG GO_VER=1.13.8
+ARG ALPINE_VER=3.10
+
+FROM golang:${GO_VER}-alpine${ALPINE_VER}
+
+WORKDIR /go/src/github.com/hyperledger/fabric-samples/chaincode/fabcar/external
+COPY . .
+
+RUN go get -d -v ./...
+RUN go install -v ./...
+
+EXPOSE 9999
+CMD ["external"]

chaincode/fabcar/external/README.md

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+# FabCar as an external service
+
+See the "Chaincode as an external service" documentation for running chaincode as an external service.
+This includes details of the external builder and launcher scripts which will peers in your Fabric network will require.
+
+The FabCar chaincode requires two environment variables to run, `CHAINCODE_SERVER_ADDRESS` and `CHAINCODE_ID`, which are described in the `chaincode.env.example` file. Copy this file to `chaincode.env` before continuing.
+
+**Note:** each organization in a Fabric network will need to follow the instructions below to host their own instance of the FabCar external service.
+
+## Packaging and installing
+
+Make sure the value of `CHAINCODE_SERVER_ADDRESS` in `chaincode.env` is correct for the FabCar external service you will be running.
+
+The peer needs a `connection.json` configuration file so that it can connect to the external FabCar service.
+Use the `CHAINCODE_SERVER_ADDRESS` value in `chaincode.env` to create the `connection.json` file with the following command (requires [jq](https://stedolan.github.io/jq/)):
+
+```
+env $(cat chaincode.env | grep -v "#" | xargs) jq -n '{"address":env.CHAINCODE_SERVER_ADDRESS,"dial_timeout": "10s","tls_required": false}' > connection.json
+```
+
+Add this file to a `code.tar.gz` archive ready for adding to a FabCar external service package:
+
+```
+tar cfz code.tar.gz connection.json
+```
+
+Package the FabCar external service using the supplied `metadata.json` file:
+
+```
+tar cfz fabcar-pkg.tgz metadata.json code.tar.gz
+```
+
+Install the `fabcar-pkg.tgz` chaincode as usual, for example:
+
+```
+peer lifecycle chaincode install ./fabcar-pkg.tgz
+```
+
+## Running the FabCar external service
+
+To run the service in a container, build a FabCar docker image:
+
+```
+docker build -t hyperledger/fabcar-sample .
+```
+
+Edit the `chaincode.env` file to configure the `CHAINCODE_ID` variable before starting a FabCar container using the following command:
+
+```
+docker run -it --rm --name fabcar.org1.example.com --hostname fabcar.org1.example.com --env-file chaincode.env --network=net_test hyperledger/fabcar-sample
+```
+
+## Starting the FabCar external service
+
+Complete the remaining lifecycle steps to start the FabCar chaincode!

chaincode/fabcar/external/chaincode.env.example

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+# CHAINCODE_SERVER_ADDRESS must be set to the host and port where the peer can
+# connect to the chaincode server
+CHAINCODE_SERVER_ADDRESS=fabcar.org1.example.com:9999
+
+# CHAINCODE_ID must be set to the Package ID that is assigned to the chaincode
+# on install. The `peer lifecycle chaincode queryinstalled` command can be
+# used to get the ID after install if required
+CHAINCODE_ID=fabcar:...

chaincode/fabcar/external/fabcar.go

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+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+	"os"
+
+	"github.com/hyperledger/fabric-chaincode-go/shim"
+	"github.com/hyperledger/fabric-contract-api-go/contractapi"
+)
+
+type ServerConfig struct {
+	CCID     string
+	Address  string
+}
+
+// SmartContract provides functions for managing a car
+type SmartContract struct {
+	contractapi.Contract
+}
+
+// Car describes basic details of what makes up a car
+type Car struct {
+	Make   string `json:"make"`
+	Model  string `json:"model"`
+	Colour string `json:"colour"`
+	Owner  string `json:"owner"`
+}
+
+// QueryResult structure used for handling result of query
+type QueryResult struct {
+	Key    string `json:"Key"`
+	Record *Car
+}
+
+// InitLedger adds a base set of cars to the ledger
+func (s *SmartContract) InitLedger(ctx contractapi.TransactionContextInterface) error {
+	cars := []Car{
+		Car{Make: "Toyota", Model: "Prius", Colour: "blue", Owner: "Tomoko"},
+		Car{Make: "Ford", Model: "Mustang", Colour: "red", Owner: "Brad"},
+		Car{Make: "Hyundai", Model: "Tucson", Colour: "green", Owner: "Jin Soo"},
+		Car{Make: "Volkswagen", Model: "Passat", Colour: "yellow", Owner: "Max"},
+		Car{Make: "Tesla", Model: "S", Colour: "black", Owner: "Adriana"},
+		Car{Make: "Peugeot", Model: "205", Colour: "purple", Owner: "Michel"},
+		Car{Make: "Chery", Model: "S22L", Colour: "white", Owner: "Aarav"},
+		Car{Make: "Fiat", Model: "Punto", Colour: "violet", Owner: "Pari"},
+		Car{Make: "Tata", Model: "Nano", Colour: "indigo", Owner: "Valeria"},
+		Car{Make: "Holden", Model: "Barina", Colour: "brown", Owner: "Shotaro"},
+	}
+
+	for i, car := range cars {
+		carAsBytes, _ := json.Marshal(car)
+		err := ctx.GetStub().PutState("CAR"+strconv.Itoa(i), carAsBytes)
+
+		if err != nil {
+			return fmt.Errorf("Failed to put to world state. %s", err.Error())
+		}
+	}
+
+	return nil
+}
+
+// CreateCar adds a new car to the world state with given details
+func (s *SmartContract) CreateCar(ctx contractapi.TransactionContextInterface, carNumber string, make string, model string, colour string, owner string) error {
+	car := Car{
+		Make:   make,
+		Model:  model,
+		Colour: colour,
+		Owner:  owner,
+	}
+
+	carAsBytes, _ := json.Marshal(car)
+
+	return ctx.GetStub().PutState(carNumber, carAsBytes)
+}
+
+// QueryCar returns the car stored in the world state with given id
+func (s *SmartContract) QueryCar(ctx contractapi.TransactionContextInterface, carNumber string) (*Car, error) {
+	carAsBytes, err := ctx.GetStub().GetState(carNumber)
+
+	if err != nil {
+		return nil, fmt.Errorf("Failed to read from world state. %s", err.Error())
+	}
+
+	if carAsBytes == nil {
+		return nil, fmt.Errorf("%s does not exist", carNumber)
+	}
+
+	car := new(Car)
+	_ = json.Unmarshal(carAsBytes, car)
+
+	return car, nil
+}
+
+// QueryAllCars returns all cars found in world state
+func (s *SmartContract) QueryAllCars(ctx contractapi.TransactionContextInterface) ([]QueryResult, error) {
+	startKey := "CAR0"
+	endKey := "CAR99"
+
+	resultsIterator, err := ctx.GetStub().GetStateByRange(startKey, endKey)
+
+	if err != nil {
+		return nil, err
+	}
+	defer resultsIterator.Close()
+
+	results := []QueryResult{}
+
+	for resultsIterator.HasNext() {
+		queryResponse, err := resultsIterator.Next()
+
+		if err != nil {
+			return nil, err
+		}
+
+		car := new(Car)
+		_ = json.Unmarshal(queryResponse.Value, car)
+
+		queryResult := QueryResult{Key: queryResponse.Key, Record: car}
+		results = append(results, queryResult)
+	}
+
+	return results, nil
+}
+
+// ChangeCarOwner updates the owner field of car with given id in world state
+func (s *SmartContract) ChangeCarOwner(ctx contractapi.TransactionContextInterface, carNumber string, newOwner string) error {
+	car, err := s.QueryCar(ctx, carNumber)
+
+	if err != nil {
+		return err
+	}
+
+	car.Owner = newOwner
+
+	carAsBytes, _ := json.Marshal(car)
+
+	return ctx.GetStub().PutState(carNumber, carAsBytes)
+}
+
+func main() {
+	// See chaincode.env.example
+	config := ServerConfig{
+		CCID:    os.Getenv("CHAINCODE_ID"),
+		Address: os.Getenv("CHAINCODE_SERVER_ADDRESS"),
+	}
+
+	chaincode, err := contractapi.NewChaincode(new(SmartContract))
+
+	if err != nil {
+		fmt.Printf("Error create fabcar chaincode: %s", err.Error())
+		return
+	}
+
+	server := &shim.ChaincodeServer{
+					CCID: config.CCID,
+					Address: config.Address,
+					CC: chaincode,
+					TLSProps: shim.TLSProperties{
+							Disabled: true,
+					},
+			}
+
+	if err := server.Start(); err != nil {
+		fmt.Printf("Error starting fabcar chaincode: %s", err.Error())
+	}
+}

chaincode/fabcar/external/go.mod

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+module github.com/hyperledger/fabric-samples/chaincode/fabcar/external
+
+go 1.13
+
+require github.com/hyperledger/fabric-contract-api-go v1.0.0