fabric網絡環境啟動過程詳解

上一節我們講到 fabric網絡環境的啟動測試，主要是使用 ./network_setup.sh up 這個命令，所以fabric網絡環境啟動的重點就在network_setup.sh這個文件中。接下來我們就分析一下network_setup.sh這個文件
network_setup.sh其中包括兩個部分，一個是利用generateArtifacts.sh腳本文件配置組織關系和頒發證書、公/私鑰、通道證書等，另一個是docker-compose-cli.yaml用於根據配置啟動集群並測試chaincode的示例代碼。下面是具體的流程圖介紹：

1.generateCerts：
 該函數使用cryptogen工具根據crypto-config.yaml來生成公私鑰和證書信息等。

2.replacePrivateKey：
 將docker-compose-e2e-template.yaml文檔中的ca私鑰替換成具體的私鑰。

3.generateChannelArtifacts：
 使用configtxgen工具根據configtx.yaml文件來生成創世區塊和通道相關信息，更新錨節點。

接著是docker-compose-cli.yaml文件
docker-compose-cli.yaml文件根據組織關系啟動docker集群，並在cli容器中執行command命令運行./scripts/script.sh腳本文件。 那./scripts/script.sh腳本具體做了什麽呢？

1.createChannel：創建channel。
2. joinChannel：將每個peer節點加入channel。
3. updateAnchorPeers：更新錨節點
4.  installChaincode：部署chaincode。 
5. instantiateChaincode：初始化chaincode。
6. chaincodeQuery：chaincode查詢

另外docker-compose-cli.yaml這個文件還有一個配置項是需要註意的地方，那就是：

file:  base/docker-compose-base.yaml

這裏的docker-compose-base.yaml其實就是Orderer和peer的基礎配置文件，包括指定端口等。

幾個重要的配置文件

1.crypto-config.yaml

基於crypto-config.yaml（此文件在../fabric/examples/e2e_cli中）生成公、私鑰和證書信息，並保存在crypto-config文件夾中。另外crypto-config.yaml還定義了組織成員以及組織下的peer節點個數。
crypto-config.yaml文件講解：
字段Name和Domain就是關於這個組織的名字和域名，這主要是用於生成證書的時候，證書內會包含該信息。而Template.Count=2是說我們要生成2套公私鑰和證書，一套是peer0.org1的，還有一套是peer1.org1的（也就指定了org中存在peer0和peer1兩個節點）。最後Users.Count=1是說每個Template下面會有幾個普通User（註意，Admin是Admin，不包含在這個計數中），這裏配置了1，也就是說我們只需要一個普通用戶[email protected] 我們可以根據實際需要調整這個配置文件，增刪Org Users等。文件內容如下：

  # ---------------------------------------------------------------------------
  # Orderer
  # ---------------------------------------------------------------------------
  - Name: Orderer
    Domain: example.com
    # ---------------------------------------------------------------------------
    # "Specs" - See PeerOrgs below for complete description
    # ---------------------------------------------------------------------------
    Specs:
      - Hostname: orderer
# ---------------------------------------------------------------------------
# "PeerOrgs" - Definition of organizations managing peer nodes
# ---------------------------------------------------------------------------
PeerOrgs:
  # ---------------------------------------------------------------------------
  # Org1
  # ---------------------------------------------------------------------------
  - Name: Org1
    Domain: org1.example.com
    # ---------------------------------------------------------------------------
    # "Specs"
    # ---------------------------------------------------------------------------
    # Uncomment this section to enable the explicit definition of hosts in your
    # configuration.  Most users will want to use Template, below
    #
    # Specs is an array of Spec entries.  Each Spec entry consists of two fields:
    #   - Hostname:   (Required) The desired hostname, sans the domain.
    #   - CommonName: (Optional) Specifies the template or explicit override for
    #                 the CN.  By default, this is the template:
    #
    #                              "{{.Hostname}}.{{.Domain}}"
    #
    #                 which obtains its values from the Spec.Hostname and
    #                 Org.Domain, respectively.
    # ---------------------------------------------------------------------------
    # Specs:
    #   - Hostname: foo # implicitly "foo.org1.example.com"
    #     CommonName: foo27.org5.example.com # overrides Hostname-based FQDN set above
    #   - Hostname: bar
    #   - Hostname: baz
    # ---------------------------------------------------------------------------
    # "Template"
    # ---------------------------------------------------------------------------
    # Allows for the definition of 1 or more hosts that are created sequentially
    # from a template. By default, this looks like "peer%d" from 0 to Count-1.
    # You may override the number of nodes (Count), the starting index (Start)
    # or the template used to construct the name (Hostname).
    #
    # Note: Template and Specs are not mutually exclusive.  You may define both
    # sections and the aggregate nodes will be created for you.  Take care with
    # name collisions
    # ---------------------------------------------------------------------------
    Template:
      Count: 2
      # Start: 5
      # Hostname: {{.Prefix}}{{.Index}} # default
    # ---------------------------------------------------------------------------
    # "Users"
    # ---------------------------------------------------------------------------
    # Count: The number of user accounts _in addition_ to Admin
    # ---------------------------------------------------------------------------
    Users:
      Count: 1
  # ---------------------------------------------------------------------------
  # Org2: See "Org1" for full specification
  # ---------------------------------------------------------------------------
  - Name: Org2
    Domain: org2.example.com
    Template:
      Count: 2
    Users:
      Count: 1

註：
peer：
Fabric 網絡中的節點，表現為一個運行著的docker容器。可以與網絡中的其他peer進行通信，每個peer都在本地保留一份ledger的副本。它是org下的組織成員。
org:
一個組織，它可以由一個或多個peer組成。
Orderer :
聯盟成員共享的中心化節點。用來對交易進行排序，是 Fabric 共識機制的重要組成部分。

2.configtx.yaml

基於configtx.yaml（此文件在../fabric/examples/e2e_cli中）生成創世區塊和通道相關信息，並保存在channel-artifacts文件夾。還可以指定背書策略。
configtx.yaml文件講解：
1.官方提供的examples/e2e_cli/configtx.yaml這個文件裏面配置了由2個Org參與的Orderer共識配置TwoOrgsOrdererGenesis，以及由2個Org參與的Channel配置：TwoOrgsChannel。
2.另外我們可以在此文件的Orderer部分設置共識的算法是Solo還是Kafka，以及共識時區塊大小，超時時間等，我們使用默認值即可，不用更改。而Peer節點的配置包含了MSP的配置，錨節點的配置。如果我們有更多的Org，或者有更多的Channel，那麽就可以根據模板進行對應的修改。
3.Policies配置也要特別註意，該配置項定義了不同角色的權限,Reader,Writer以及Admin分別對應讀，寫，以及admin權限,讀權限角色只能從別的peer節點同步賬本而不能發起交易，只有writer定義項下的角色才擁有發起交易的也就是調用chaincode的invoke方法的權限(不一定都是invoke方案，只要涉及到chaincode中狀態修改的方法，都只有擁有writer權限或admin權限的角色才能調用)。以該配置的Organizations配置下的Org1配置為例,"OR(‘Org1MSP.admin‘, ‘Org1MSP.client‘)",表示org1的msp服務中的admin或者client角色擁有發起交易的權限。文件內容如下：

# Copyright IBM Corp. All Rights Reserved.
#
# SPDX-License-Identifier: Apache-2.0
#

---
################################################################################
#
#   Profile
#
#   - Different configuration profiles may be encoded here to be specified
#   as parameters to the configtxgen tool
#
################################################################################
Profiles:

    TwoOrgsOrdererGenesis:
        Orderer:
            <<: *OrdererDefaults
            Organizations:
                - *OrdererOrg
        Consortiums:
            SampleConsortium:
                Organizations:
                    - *Org1
                    - *Org2
    TwoOrgsChannel:
        Consortium: SampleConsortium
        Application:
            <<: *ApplicationDefaults
            Organizations:
                - *Org1
                - *Org2

################################################################################
#
#   Section: Organizations
#
#   - This section defines the different organizational identities which will
#   be referenced later in the configuration.
#
################################################################################
Organizations:

    # SampleOrg defines an MSP using the sampleconfig.  It should never be used
    # in production but may be used as a template for other definitions
    - &OrdererOrg
        # DefaultOrg defines the organization which is used in the sampleconfig
        # of the fabric.git development environment
        Name: OrdererOrg

        # ID to load the MSP definition as
        ID: OrdererMSP

        # MSPDir is the filesystem path which contains the MSP configuration
        MSPDir: crypto-config/ordererOrganizations/example.com/msp

    - &Org1
        # DefaultOrg defines the organization which is used in the sampleconfig
        # of the fabric.git development environment
        Name: Org1MSP

        # ID to load the MSP definition as
        ID: Org1MSP

        MSPDir: crypto-config/peerOrganizations/org1.example.com/msp

        AnchorPeers:
            # AnchorPeers defines the location of peers which can be used
            # for cross org gossip communication.  Note, this value is only
            # encoded in the genesis block in the Application section context
            - Host: peer0.org1.example.com
              Port: 7051

    - &Org2
        # DefaultOrg defines the organization which is used in the sampleconfig
        # of the fabric.git development environment
        Name: Org2MSP

        # ID to load the MSP definition as
        ID: Org2MSP

        MSPDir: crypto-config/peerOrganizations/org2.example.com/msp

        AnchorPeers:
            # AnchorPeers defines the location of peers which can be used
            # for cross org gossip communication.  Note, this value is only
            # encoded in the genesis block in the Application section context
            - Host: peer0.org2.example.com
              Port: 7051

################################################################################
#
#   SECTION: Orderer
#
#   - This section defines the values to encode into a config transaction or
#   genesis block for orderer related parameters
#
################################################################################
Orderer: &OrdererDefaults

    # Orderer Type: The orderer implementation to start
    # Available types are "solo" and "kafka"
    OrdererType: solo

    Addresses:
        - orderer.example.com:7050

    # Batch Timeout: The amount of time to wait before creating a batch
    BatchTimeout: 2s

    # Batch Size: Controls the number of messages batched into a block
    BatchSize:

        # Max Message Count: The maximum number of messages to permit in a batch
        MaxMessageCount: 10

        # Absolute Max Bytes: The absolute maximum number of bytes allowed for
        # the serialized messages in a batch.
        AbsoluteMaxBytes: 98 MB

        # Preferred Max Bytes: The preferred maximum number of bytes allowed for
        # the serialized messages in a batch. A message larger than the preferred
        # max bytes will result in a batch larger than preferred max bytes.
        PreferredMaxBytes: 512 KB

    Kafka:
        # Brokers: A list of Kafka brokers to which the orderer connects
        # NOTE: Use IP:port notation
        Brokers:
            - 127.0.0.1:9092

    # Organizations is the list of orgs which are defined as participants on
    # the orderer side of the network
    Organizations:

################################################################################
#
#   SECTION: Application
#
#   - This section defines the values to encode into a config transaction or
#   genesis block for application related parameters
#
################################################################################
Application: &ApplicationDefaults

    # Organizations is the list of orgs which are defined as participants on
    # the application side of the network
    Organizations:

Fabric網絡環境啟動過程詳解