block-listener

README

Deprecation

Please note that events API available in Hyperledger Fabric v1.0.0 will be deprecated in favour of new events delivery API

service Deliver {
    // deliver first requires an Envelope of type ab.DELIVER_SEEK_INFO with Payload data as a marshaled orderer.SeekInfo message,
    // then a stream of block replies is received.
    rpc Deliver (stream common.Envelope) returns (stream DeliverResponse) {
    }
    // deliver first requires an Envelope of type ab.DELIVER_SEEK_INFO with Payload data as a marshaled orderer.SeekInfo message,
    // then a stream of **filtered** block replies is received.
    rpc DeliverFiltered (stream common.Envelope) returns (stream DeliverResponse) {
    }
}

Please explore eventsclient example for demonstration of using new APIs.

What is block-listener

block-listener.go connects to a peer in order to receive block and chaincode events (if there are chaincode events being sent).

To Run

1. go build

2. ./block-listener -events-address=<peer-address> -events-from-chaincode=<chaincode-id> -events-mspdir=<msp-directory> -events-mspid=<msp-id>

Please note that the default MSP under fabric/sampleconfig will be used if no MSP parameters are provided.

Example with the e2e_cli example

The block listener can be used with TLS enabled or disabled. By default, the e2e_cli example will have TLS enabled. In order to allow the block-listener sample to connect to peers on e2e_cli example with a TLS enabled, the easiest way would be to map 127.0.0.1 to the hostname of peer that you are connecting to, such as peer0.org1.example.com. For example on *nix based systems this would be an entry in /etc/hosts file.

If you would prefer to disable TLS, you may do so by setting CORE_PEER_TLS_ENABLED=false in docker-compose-cli.yaml and base/peer-base.yaml as well as ORDERER_GENERAL_TLS_ENABLED=false inbase/docker-compose-base.yaml.

Next, run the e2e_cli example.

Once the "All in one" command:

./network_setup.sh up

has completed, attach the event client to peer peer0.org1.example.com by doing the following (assuming you are running block-listener in the host environment) if TLS is enabled:

CORE_PEER_TLS_ENABLED=true CORE_PEER_TLS_ROOTCERT_FILE=$GOPATH/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/peerOrganizations/org1.example.com/peers/peer0.org1.example.com/tls/ca.crt ./block-listener -events-address=peer0.org1.example.com:7053 -events-mspdir=$GOPATH/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp -events-mspid=Org1MSP

If TLS is disabled, you can simply run:

./block-listener -events-address=peer0.org1.example.com:7053 -events-mspdir=$GOPATH/src/github.com/hyperledger/fabric/examples/e2e_cli/crypto-config/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp -events-mspid=Org1MSP

The event client should output "Event Address: peer0.org1.example.com:7053" and wait for events.

Exec into the cli container:

docker exec -it cli bash

Next, setup the environment variables for peer0.org1.example.com. If TLS is enabled:

CORE_PEER_MSPCONFIGPATH=$GOPATH/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp
CORE_PEER_ADDRESS=peer0.org1.example.com:7051
CORE_PEER_LOCALMSPID="Org1MSP"
ORDERER_CA=$GOPATH/src/github.com/hyperledger/fabric/peer/crypto/ordererOrganizations/example.com/tlsca/tlsca.example.com-cert.pem

If TLS is disabled:

CORE_PEER_MSPCONFIGPATH=$GOPATH/src/github.com/hyperledger/fabric/peer/crypto/peerOrganizations/org1.example.com/users/Admin@org1.example.com/msp
CORE_PEER_ADDRESS=peer0.org1.example.com:7051
CORE_PEER_LOCALMSPID="Org1MSP"

Create an invoke transaction. If TLS is enabled:

peer chaincode invoke -o orderer.example.com:7050 --tls --cafile $ORDERER_CA -C mychannel -n mycc -c '{"Args":["invoke","a","b","10"]}'

If TLS is disabled:

peer chaincode invoke -o orderer.example.com:7050 -C mychannel -n mycc -c '{"Args":["invoke","a","b","10"]}'

Now you should see the block content displayed in the terminal running the block listener.

This work is licensed under a Creative Commons Attribution 4.0 International License.