peer channel fetch

提取指定区块并写入文件。

相关链接：Fabric开发环境Window一键安装工具

使用方法

~$ peer channel fetch <newest|oldest|config|(number)> [outputfile] [flags]

命令标志

  -c, --channelID string   In case of a newChain command, the channel ID to create. It must be all lower case, less than 250 characters long and match the regular expression: [a-z][a-z0-9.-]*
  -h, --help               help for fetch

全局标志：

      --cafile string                       Path to file containing PEM-encoded trusted certificate(s) for the ordering endpoint
      --certfile string                     Path to file containing PEM-encoded X509 public key to use for mutual TLS communication with the orderer endpoint
      --clientauth                          Use mutual TLS when communicating with the orderer endpoint
      --connTimeout duration                Timeout for client to connect (default 3s)
      --keyfile string                      Path to file containing PEM-encoded private key to use for mutual TLS communication with the orderer endpoint
  -o, --orderer string                      Ordering service endpoint
      --ordererTLSHostnameOverride string   The hostname override to use when validating the TLS connection to the orderer.
      --tls                                 Use TLS when communicating with the orderer endpoint

示例代码

下面的示例使用newest选项获取最新的通道区块，并存入文件mychannel.block：

peer channel fetch newest mychannel.block -c mychannel --orderer orderer.example.com:7050

2018-02-25 13:10:16.137 UTC [channelCmd] InitCmdFactory -> INFO 003 Endorser and orderer connections initialized
2018-02-25 13:10:16.144 UTC [channelCmd] readBlock -> INFO 00a Received block: 32
2018-02-25 13:10:16.145 UTC [main] main -> INFO 00b Exiting.....

查看获取到的文件：

~$ ls -l

-rw-r--r-- 1 root root 11982 Feb 25 13:10 mychannel.block

你可以看到获取到的区块序号为32，区块信息写入文件mychannel.block。

下面的示例使用区块序号选项提取指定的区块 —— 在本例中为16 —— 并存入默认区块文件：

~$ peer channel fetch 16  -c mychannel --orderer orderer.example.com:7050

2018-02-25 13:46:50.296 UTC [channelCmd] InitCmdFactory -> INFO 003 Endorser and orderer connections initialized
2018-02-25 13:46:50.302 UTC [channelCmd] readBlock -> INFO 00a Received block: 16
2018-02-25 13:46:50.302 UTC [main] main -> INFO 00b Exiting.....

查看获取到的文件：

~$ ls -l

-rw-r--r-- 1 root root 11982 Feb 25 13:10 mychannel.block
-rw-r--r-- 1 root root  4783 Feb 25 13:46 mychannel_16.block

可以看到获取到的区块编号为16，该区块信息被写入默认文件mychannel_16.block。

对于配置区块，可以使用configtxlatore命令解码区块文件。用户交易区块也可以解码，但需要 编写一个额外的程序来完成这一工作。