Channel Configuration (configtxgen)

This document describe the usage for the configtxgen utility for manipulating Hyperledger Fabric channel configuration.

For now, the tool is primarily focused on generating the genesis block for bootstrapping the orderer, but it is intended to be enhanced in the future for generating new channel configurations as well as reconfiguring existing channels.

Configuration Profiles

The configuration parameters supplied to the configtxgen tool are primarily provided by the configtx.yaml file. This file is located at fabric/sampleconfig/configtx.yaml in the fabric.git repository.

This configuration file is split primarily into three pieces.

1. The Profiles section. By default, this section includes some sample configurations which can be used for development or testing scenarios, and refer to crypto material present in the fabric.git tree. These profiles can make a good starting point for construction a real deployment profile. The configtxgen tool allows you to specify the profile it is operating under by passing the -profile flag. Profiles may explicitly declare all configuration, but usually inherit configuration from the defaults in (3) below.
2. The Organizations section. By default, this section includes a single reference to the sampleconfig MSP definition. For production deployments, the sample organization should be removed, and the MSP definitions of the network members should be referenced and defined instead. Each element in the Organizations section should be tagged with an anchor label such as &orgName which will allow the definition to be referenced in the Profiles sections.
3. The default sections. There are default sections for Orderer and Application configuration, these include attributes like BatchTimeout and are generally used as the base inherited values for the profiles.

This configuration file may be edited, or, individual properties may be overridden by setting environment variables, such as CONFIGTX_ORDERER_ORDERERTYPE=kafka. Note that the Profiles element and profile name do not need to be specified.

Bootstrapping the orderer

After creating a configuration profile as desired, simply invoke

configtxgen -profile <profile_name>

This will produce a genesis.block file in the current directory. You may optionally specify another filename by passing in the -path parameter, or, you may skip the writing of the file by passing the dryRun parameter if you simply wish to test parsing of the file.

Then, to utilize this genesis block, before starting the orderer, simply specify ORDERER_GENERAL_GENESISMETHOD=file and ORDERER_GENERAL_GENESISFILE=$PWD/genesis.block or modify the orderer.yaml file to encode these values.

Creating a channel

The tool can also output a channel creation tx by executing

configtxgen -profile <profile_name> -channelID <channel_name> -outputCreateChannelTx <tx_filename>

This will output a marshaled Envelope message which may be sent to broadcast to create a channel.

Reviewing a configuration

In addition to creating configuration, the configtxgen tool is also capable of inspecting configuration.

It supports inspecting both configuration blocks, and configuration transactions. You may use the inspect flags -inspectBlock and -inspectChannelCreateTx respectively with the path to a file to inspect to output a human readable (JSON) representation of the configuration.

You may even wish to combine the inspection with generation. For example:

$ build/bin/configtxgen -channelID foo -outputBlock foo.block -inspectBlock foo.block
2017/03/01 21:24:24 Loading configuration
2017/03/01 21:24:24 Checking for configtx.yaml at:
2017/03/01 21:24:24 Checking for configtx.yaml at:
2017/03/01 21:24:24 Checking for configtx.yaml at: /home/yellickj/go/src/github.com/hyperledger/fabric/common/configtx/tool
2017/03/01 21:24:24 map[orderer:map[BatchSize:map[MaxMessageCount:10 AbsoluteMaxBytes:99 MB PreferredMaxBytes:512 KB] Kafka:map[Brokers:[127.0.0.1:9092]] Organizations:<nil> OrdererType:solo Addresses:[127.0.0.1:7050] BatchTimeout:10s] application:map[Organizations:<nil>] profiles:map[SampleInsecureSolo:map[Orderer:map[BatchTimeout:10s BatchSize:map[MaxMessageCount:10 AbsoluteMaxBytes:99 MB PreferredMaxBytes:512 KB] Kafka:map[Brokers:[127.0.0.1:9092]] Organizations:<nil> OrdererType:solo Addresses:[127.0.0.1:7050]] Application:map[Organizations:<nil>]] SampleInsecureKafka:map[Orderer:map[Addresses:[127.0.0.1:7050] BatchTimeout:10s BatchSize:map[AbsoluteMaxBytes:99 MB PreferredMaxBytes:512 KB MaxMessageCount:10] Kafka:map[Brokers:[127.0.0.1:9092]] Organizations:<nil> OrdererType:kafka] Application:map[Organizations:<nil>]] SampleSingleMSPSolo:map[Orderer:map[OrdererType:solo Addresses:[127.0.0.1:7050] BatchTimeout:10s BatchSize:map[MaxMessageCount:10 AbsoluteMaxBytes:99 MB PreferredMaxBytes:512 KB] Kafka:map[Brokers:[127.0.0.1:9092]] Organizations:[map[Name:SampleOrg ID:DEFAULT MSPDir:msp BCCSP:map[Default:SW SW:map[Hash:SHA3 Security:256 FileKeyStore:map[KeyStore:<nil>]]] AnchorPeers:[map[Host:127.0.0.1 Port:7051]]]]] Application:map[Organizations:[map[Name:SampleOrg ID:DEFAULT MSPDir:msp BCCSP:map[Default:SW SW:map[Hash:SHA3 Security:256 FileKeyStore:map[KeyStore:<nil>]]] AnchorPeers:[map[Port:7051 Host:127.0.0.1]]]]]]] organizations:[map[Name:SampleOrg ID:DEFAULT MSPDir:msp BCCSP:map[Default:SW SW:map[Hash:SHA3 Security:256 FileKeyStore:map[KeyStore:<nil>]]] AnchorPeers:[map[Host:127.0.0.1 Port:7051]]]]]
2017/03/01 21:24:24 Generating genesis block
2017/03/01 21:24:24 Writing genesis block
2017/03/01 21:24:24 Inspecting block
2017/03/01 21:24:24 Parsing genesis block
Config for channel: foo
{
    "": {
        "Values": {},
        "Groups": {
            "/Channel": {
                "Values": {
                    "HashingAlgorithm": {
                        "Version": "0",
                        "ModPolicy": "",
                        "Value": {
                            "name": "SHA256"
                        }
                    },
                    "BlockDataHashingStructure": {
                        "Version": "0",
                        "ModPolicy": "",
                        "Value": {
                            "width": 4294967295
                        }
                    },
                    "OrdererAddresses": {
                        "Version": "0",
                        "ModPolicy": "",
                        "Value": {
                            "addresses": [
                                "127.0.0.1:7050"
                            ]
                        }
                    }
                },
                "Groups": {
                    "/Channel/Orderer": {
                        "Values": {
                            "ChainCreationPolicyNames": {
                                "Version": "0",
                                "ModPolicy": "",
                                "Value": {
                                    "names": [
                                        "AcceptAllPolicy"
                                    ]
                                }
                            },
                            "ConsensusType": {
                                "Version": "0",
                                "ModPolicy": "",
                                "Value": {
                                    "type": "solo"
                                }
                            },
                            "BatchSize": {
                                "Version": "0",
                                "ModPolicy": "",
                                "Value": {
                                    "maxMessageCount": 10,
                                    "absoluteMaxBytes": 103809024,
                                    "preferredMaxBytes": 524288
                                }
                            },
                            "BatchTimeout": {
                                "Version": "0",
                                "ModPolicy": "",
                                "Value": {
                                    "timeout": "10s"
                                }
                            },
                            "IngressPolicyNames": {
                                "Version": "0",
                                "ModPolicy": "",
                                "Value": {
                                    "names": [
                                        "AcceptAllPolicy"
                                    ]
                                }
                            },
                            "EgressPolicyNames": {
                                "Version": "0",
                                "ModPolicy": "",
                                "Value": {
                                    "names": [
                                        "AcceptAllPolicy"
                                    ]
                                }
                            }
                        },
                        "Groups": {}
                    },
                    "/Channel/Application": {
                        "Values": {},
                        "Groups": {}
                    }
                }
            }
        }
    }
}