Create a Custom Network and Deploy your own Chaincode with Hyperledger Fabric v2.1

In this story, we will create a custom network and deploy a sample chaincode with Hyperledger Fabric v2.1. After that, we will query the chaincode and interact with the network by 2 peers that we will create.

Firstly, we need to install all prerequisites listed here. If you don’t have installed it before, you can use the following link as a guide. There is more than the installation of prerequisites but it can be good if you complete the whole guide. However, only the installation of prerequisites and the installation of samples, binaries, and docker images parts are necessary for this story.

Hyperledger Fabric v2.1 Installation Guide — Prerequisites & Bring up the Test Network

If we installed prerequisites, samples, binaries, and docker images successfully, we must have a fabric-samples folder and we can start from creating a custom network.

Create a custom network and bring it up

We create a folder whose name is burakcan-network under the fabric-samples folder. In our network, there are 3 nodes including 2 organizations, which areBurakcan1 and Burakcan2 , and 1 orderer so we need to generate all certificates and keys for proving whether the nodes are really themselves. We will use the cryptogen tool that provides to generate the cryptographic material for our network entities and we had already installed it when we installed platform-specific binaries. It places under fabric-samples/bin folder. It consumes the crypto-config.yaml file that contains the network topology and allows us to generate a set of certificates and keys for both the Organizations and the components that belong to those Organizations.

I don’t mention more than this but you can learn more about the tool from here.

That’s why we create the following file under the burakcan-network directory. We define an Orderer Org (OrdererOrg) and 2 Peer Org (Burakcan1 and Burakcan2). Each count value in organizations specifies the number of peers in that organization.

After defining the crypto-config.yaml file, we execute the following command channel under the burakcan-network directory.

../bin/cryptogen generate --config crypto-config.yaml --output=crypto-config

We should see the message looks like below.

cryptogen

Then we will continue with the configtxgen tool that we had already installed when we installed platform-specific binaries and it places under fabric-samples/bin folder too. It provides the generating these important configuration artifacts;

• 1 orderer genesis block
• 1 channel configuration transaction
• 2 anchor peer transactions (It must be for each organization and we have Burakcan1 and Burakcan2 organizations so we will generate 2 of them)

You can learn more about the configtxgen tool from here.

It consumes the configtx.yaml file that contains the definitions for the network so we will create the following file under the burakcan-network directory.

After defining the configtx.yaml file, we execute the following commands orderly to generate configuration artifacts we mentioned above under the burakcan-network directory;

• To generating orderer genesis block;

../bin/configtxgen -profile OrdererGenesis -outputBlock ./channel-artifacts/genesis.block -channelID channelorderergenesis

orderer genesis block

• To generating channel configuration transactions;

../bin/configtxgen -profile ChannelDemo -outputCreateChannelTx ./channel-artifacts/channel.tx -channelID channeldemo

channel configuration transaction

• To generating anchor peer transaction for Burakcan1;

../bin/configtxgen -profile ChannelDemo -outputAnchorPeersUpdate ./channel-artifacts/Burakcan1Anchor.tx -channelID channeldemo -asOrg Burakcan1MSP

anchor peer transaction for Burakcan1 Org

• To generating anchor peer transaction for Burakcan2;

../bin/configtxgen -profile ChannelDemo -outputAnchorPeersUpdate ./channel-artifacts/Burakcan2Anchor.tx -channelID channeldemo -asOrg Burakcan2MSP

anchor peer transaction for Burakcan2 Org

Then, we need to create some files under the burakcan-network directory due to specify docker files and define their locations. We create base folder under the burakcan-network directory and the following docker-compose-base.yaml and peer-base.yaml files, which set up that base for our network, inside it.

There is only one file remain we need to create. It is the docker-compose-cli.yaml file that is extended from the docker-compose-base.yaml file and it must be placed under the root of the burakcan-network directory. We will use a cli-container for each organization by bringing up the network or deploying, querying, and interacting chaincode so we create the following file.

Then set up the COMPOSE_PROJECT_NAME variable due to it may cause a problem when we bring our network up.

echo COMPOSE_PROJECT_NAME=net > .env

Now, we can bring our network up and we should see something looks like in the image below;

docker-compose -f docker-compose-cli.yaml up -d

bring up the network

Configure and create the channel

If you have brought the network up successfully, we can continue by configuring and creating the channel we will use. We open 2 more terminals to configure the channel to our peers.

We will enter the CLI container separately for each peer by docker exec command. Also, we can define the environment variables together with this command or after when we execute it. It doesn’t matter which way you choose.

• Enter the following command from one terminal to peer Burakcan1

docker exec -e "CORE_PEER_LOCALMSPID=Burakcan1MSP" -e "CORE_PEER_TLS_ROOTCERT_FILE=/opt/gopath/fabric-samples/burakcan-network/crypto-config/peerOrganizations/be1.burakcan-network.com/peers/peer0.be1.burakcan-network.com/tls/ca.crt" -e "CORE_PEER_MSPCONFIGPATH=/opt/gopath/fabric-samples/burakcan-network/crypto-config/peerOrganizations/be1.burakcan-network.com/users/Admin@be1.burakcan-network.com/msp" -e "CORE_PEER_ADDRESS=peer0.be1.burakcan-network.com:7051" -it cli bash

docker exec for Burakcan1

• Enter the following command from the other terminal to peer Burakcan2

docker exec -e "CORE_PEER_LOCALMSPID=Burakcan2MSP" -e "CORE_PEER_TLS_ROOTCERT_FILE=/opt/gopath/fabric-samples/burakcan-network/crypto-config/peerOrganizations/be2.burakcan-network.com/peers/peer0.be2.burakcan-network.com/tls/ca.crt" -e "CORE_PEER_MSPCONFIGPATH=/opt/gopath/fabric-samples/burakcan-network/crypto-config/peerOrganizations/be2.burakcan-network.com/users/Admin@be2.burakcan-network.com/msp" -e "CORE_PEER_ADDRESS=peer0.be2.burakcan-network.com:7051" -it cli bash

docker exec for Burakcan2

From here, some operations will be made in just one peer and some of them will be made together. We are starting from setting ORDERER_CA variables in all terminals by following way;

export ORDERER_CA=/opt/gopath/fabric-samples/burakcan-network/crypto-config/ordererOrganizations/burakcan-network.com/orderers/orderer.burakcan-network.com/msp/tlscacerts/tlsca.burakcan-network.com-cert.pem

Then we create the channel by the following command. There is no need to execute it in both terminals; just one is enough. We entitled the channel name as channeldemo.

peer channel create -o orderer.burakcan-network.com:7050 -c channeldemo -f /opt/gopath/fabric-samples/burakcan-network/channel-artifacts/channel.tx — tls — cafile $ORDERER_CA

create the channel

Then we join this channel from each peer separately so we will execute the following command in both terminals and we should see the image below.

peer channel join -b channeldemo.block --tls --cafile $ORDERER_CA

join the channel

After joining the channel we update the channel from each peer separately.

• To peer Burakcan1

peer channel update -o orderer.burakcan-network.com:7050 -c channeldemo -f /opt/gopath/fabric-samples/burakcan-network/channel-artifacts/Burakcan1Anchor.tx --tls --cafile $ORDERER_CA

update the channel

• To peer Burakcan2

peer channel update -o orderer.burakcan-network.com:7050 -c channeldemo -f /opt/gopath/fabric-samples/burakcan-network/channel-artifacts/Burakcan2Anchor.tx --tls --cafile $ORDERER_CA

update the channel

Define and deploying the chaincode

If we have finished the channel stuff successfully, we can continue by defining and deploying the chaincode as the new chaincode lifecycle that has changed with Hyperledger Fabric v2. We won’t look inside this new lifecycle, but if you want, you can look at the following story for more detail.

The Chaincode Lifecycle on Hyperledger Fabric v2

A chaincode can be written by Go, Java, or Javascript. We will create our chaincode by using the Go language in this example. Firstly we create a directory whose name is be_chaincode to keeps our chaincode.

Since we have defined ../chaincode path as the /opt/gopath/src/chain path in the volume part of CLI in the docker-compose-cli.yaml file by the row

./../chaincode/:/opt/gopath/src/chain

we can access this directory only used by the /opt/gopath/src/chain path in CLI container. In addition to creating the chaincode by the way that will be defined below, we can directly create the be.go file under the ../chaincode/be_chaincode directory.

mkdir /opt/gopath/src/chain/be_chaincode
mkdir /opt/gopath/src/chain/be_chaincode/go
vi /opt/gopath/src/chain/be_chaincode/go/be.go

Then we copy the following chaincode in the file whose name is be.go that was created with the command above. “github.com/hyperledger/fabric-contract-api-go/contractapi”

In here, we need to get the dependency github.com/hyperledger/fabric-contract-api-go/contractapi that we wrote inside the chaincode and other go dependencies. We will be able to execute it any terminal we want. There is no need to execute both terminals.

go get github.com/hyperledger/fabric-chaincode-go/shim
go get github.com/hyperledger/fabric-contract-api-go/contractapi

We can modify the go.mod and vendor files in your directory to avoid the command above, and execute GO111MODULE command. But the chaincode under abstore example that has been downloaded with Fabric samples has correct files, so we use their go.mod and vendor files by the following commands

cd /opt/gopath/src/chain/abstore/go
GO111MODULE=on go mod vendor
cd -

GO111MODULE

According to the chaincode lifecycle, we package our chaincode by executing the following command in any terminal.

peer lifecycle chaincode package becc.tar.gz --path chain/be_chaincode/go/ --lang golang --label becc_1

package the chaincode

Now, we will install this package from all peers so we execute the following command from all terminals.

peer lifecycle chaincode install becc.tar.gz

install the chaincode

We will query install from all peers so we execute the following command from all terminals and we will get Package ID that will be used at the next steps.

peer lifecycle chaincode queryinstalled

queryinstalled the chaincode

To easy usage, we set Package ID into the CC_PACKAGE_ID variable.

CC_PACKAGE_ID=becc_1:5f80a06945e5e36824c400dad9a4ccfe0040cc0551fe1bb1b95a68f892cf56c2

We will approve the chaincode definition after the chaincode package has been installed on our peers, so we execute the following command from all terminals.

peer lifecycle chaincode approveformyorg -o orderer.burakcan-network.com:7050 --tls true --cafile $ORDERER_CA --channelID channeldemo --name becc --version 1 --init-required --package-id $CC_PACKAGE_ID --sequence 1 --signature-policy "OR('Burakcan1MSP.peer', 'Burakcan2MSP.peer')"

approve the chaincode from all peers

Before committing the chaincode, we can check whether Burakcan1MSP and Burakcan2MSP are ready to commit. It is not necessary, but beneficial. Therefore, we execute the following command in one peer.

peer lifecycle chaincode checkcommitreadiness --channelID channeldemo --name becc --version 1 --sequence 1 --output json --init-required --signature-policy "OR('Burakcan1MSP.peer', 'Burakcan2MSP.peer')"

check commit readiness

If we see Burakcan1MSP and Burakcan2MSP are ready from approvals, we can commit the chaincode. Before committing the chaincode, we set the path of certificates of each peer that we have defined aspeer0.be1.burakcan-network.com:7051 and peer0.be2.burakcan-network.com:7051 into PEER_BE1_TLSROOTCERTFILES and PEER_BE1_TLSROOTCERTFILES variables to easy use.

PEER_BE1_TLSROOTCERTFILES=/opt/gopath/fabric-samples/burakcan-network/crypto-config/peerOrganizations/be1.burakcan-network.com/peers/peer0.be1.burakcan-network.com/tls/ca.crt
PEER_BE2_TLSROOTCERTFILES=/opt/gopath/fabric-samples/burakcan-network/crypto-config/peerOrganizations/be2.burakcan-network.com/peers/peer0.be2.burakcan-network.com/tls/ca.crt

Then, we commit the chaincode in one peer and we saw it is valid for peer0.be1.burakcan-network.com:7051 and peer0.be2.burakcan-network.com:7051 peers.

peer lifecycle chaincode commit -o orderer.burakcan-network.com:7050 --tls true --cafile $ORDERER_CA --channelID channeldemo --name becc --peerAddresses peer0.be1.burakcan-network.com:7051 --tlsRootCertFiles $PEER_BE1_TLSROOTCERTFILES --peerAddresses peer0.be2.burakcan-network.com:7051 --tlsRootCertFiles $PEER_BE2_TLSROOTCERTFILES --version 1 --sequence 1 --init-required --signature-policy "OR('Burakcan1MSP.peer', 'Burakcan2MSP.peer')"

commit the chaincode

We can check the chaincode definitions that we have committed by the following command.

peer lifecycle chaincode querycommitted --channelID channeldemo --name becc

querycommit the chaincode

Query the chaincode and interact with the network

After committing the chaincode, we are ready to query the chaincode and interact with the network if everything is ok. We can use the old chaincode lifecycle while we are querying with Hyperledger Fabric v2.

Since we must invoke the chaincode firstly, we use peer chaincode invoke command in any terminal and call the InitLedger method as you see in chaincode that we have defined previously.

peer chaincode invoke -o orderer.burakcan-network.com:7050 --tls true --cafile $ORDERER_CA -C channeldemo -n becc --peerAddresses peer0.be1.burakcan-network.com:7051 --tlsRootCertFiles $PEER_BE1_TLSROOTCERTFILES --peerAddresses peer0.be2.burakcan-network.com:7051 --tlsRootCertFiles $PEER_BE2_TLSROOTCERTFILES --isInit -c '{"function":"initLedger","Args":[]}'

invoke the chaincode

If we see the status:200 message, we can query the chaincode whatever peer we want. That’s why we call the QueryAllProducts method in peer0.be1.burakcan-network.com:7051 peer and it will show all products which we put the ledger in the InitLedger method.

peer chaincode query -C channeldemo -n becc -c '{"Args":["queryAllProducts"]}'

query all products

Now, we call the invoke command again due to we want to change product price which means we want to make a change on an asset. When a network member wants to transfer or change an asset on the ledger, the chaincode is invoked. Therefore we call theChangeProductPrice method by executing the following command in peer0.be1.burakcan-network.com:7051 peer.

peer chaincode invoke -o orderer.burakcan-network.com:7050 --tls true --cafile $ORDERER_CA -C channeldemo -n becc --peerAddresses peer0.be1.burakcan-network.com:7051 --tlsRootCertFiles $PEER_BE1_TLSROOTCERTFILES --peerAddresses peer0.be2.burakcan-network.com:7051 --tlsRootCertFiles $PEER_BE2_TLSROOTCERTFILES -c '{"function":"changeProductPrice","Args":["PRODUCT0", 350]}'

change product price

If the command above worked correctly, we should see the PRODUCT0 price as 350 instead of 250. That’s why we call the QueryAllProducts method in peer0.be2.burakcan-network.com:7051 peer.

peer chaincode query -C channeldemo -n becc -c '{"Args":["queryAllProducts"]}'

query all products

Yes, we can see the PRODUCT0 price as 350 instead of 250 so it means everything is working correctly.

Down the network

When our job is finish, we can down our network so we go to the terminal that we used to bring up the network and execute the following command.

docker-compose -f docker-compose-cli.yaml down

After down the network, using the following commands are beneficial to avoid the possible problems.

docker rm $(docker ps -aq)
docker volume prune

Sometimes we want to upgrade or deploy the new chaincode we may face the kind of error which says “chaincode definition for ‘becc’ is exist but chaincode is not installed” although we executed peer chaincode lifecycle installed command. At this moment, we need to delete the images of the chaincode that we installed for peers. We can see these images by executing the following command. The top 2 images belong to the chaincode that we installed in peer0.be1.burakcan-network.com:7051 and peer0.be2.burakcan-network.com:7051 peers.

docker images

docker images

docker rmi <IMAGE_ID>

We can delete it by their IMAGE ID property. You can write the image id from above instead of the <IMAGE_ID> variable for each chaincode docker image. You can make a fresh start.

That’s it, we have;

• installed Prerequisites
• installed Samples, Binaries, and Docker Images
• brought up the custom burakcan-network
• created a channel whose name is channeldemo
• deployed be.go as the chaincode becc
• queried and invoked the chaincode
• interacted with the custom burakcan-network

in this story.

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