peer channel
The peer channel command allows administrators to perform channel related
operations on a peer, such as joining a channel or listing the channels to which
a peer is joined.
Syntax
The peer channel command has the following subcommands:
- create
- fetch
- getinfo
- join
- list
- signconfigtx
- update
peer channel
Operate a channel: create|fetch|join|list|update|signconfigtx|getinfo.
Usage:
peer channel [command]
Available Commands:
create Create a channel
fetch Fetch a block
getinfo get blockchain information of a specified channel.
join Joins the peer to a channel.
list List of channels peer has joined.
signconfigtx Signs a configtx update.
update Send a configtx update.
Flags:
--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)
-h, --help help for channel
--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
Use "peer channel [command] --help" for more information about a command.
peer channel create
Create a channel and write the genesis block to a file.
Usage:
peer channel create [flags]
Flags:
-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.-]*
-f, --file string Configuration transaction file generated by a tool such as configtxgen for submitting to orderer
-h, --help help for create
--outputBlock string The path to write the genesis block for the channel. (default ./<channelID>.block)
-t, --timeout duration Channel creation timeout (default 10s)
Global Flags:
--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
peer channel fetch
Fetch a specified block, writing it to a file.
Usage:
peer channel fetch <newest|oldest|config|(number)> [outputfile] [flags]
Flags:
--bestEffort Whether fetch requests should ignore errors and return blocks on a best effort basis
-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
Global Flags:
--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
peer channel getinfo
get blockchain information of a specified channel. Requires '-c'.
Usage:
peer channel getinfo [flags]
Flags:
-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 getinfo
Global Flags:
--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
peer channel join
Joins the peer to a channel.
Usage:
peer channel join [flags]
Flags:
-b, --blockpath string Path to file containing genesis block
-h, --help help for join
Global Flags:
--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
peer channel list
List of channels peer has joined.
Usage:
peer channel list [flags]
Flags:
-h, --help help for list
Global Flags:
--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
peer channel signconfigtx
Signs the supplied configtx update file in place on the filesystem. Requires '-f'.
Usage:
peer channel signconfigtx [flags]
Flags:
-f, --file string Configuration transaction file generated by a tool such as configtxgen for submitting to orderer
-h, --help help for signconfigtx
Global Flags:
--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
peer channel update
Signs and sends the supplied configtx update file to the channel. Requires '-f', '-o', '-c'.
Usage:
peer channel update [flags]
Flags:
-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.-]*
-f, --file string Configuration transaction file generated by a tool such as configtxgen for submitting to orderer
-h, --help help for update
Global Flags:
--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
Example Usage
peer channel create examples
Here's an example that uses the --orderer global flag on the peer channel
create command.
- Create a sample channel
mychanneldefined by the configuration transaction contained in file./createchannel.tx. Use the orderer atorderer.example.com:7050.
``` peer channel create -c mychannel -f ./createchannel.tx --orderer orderer.example.com:7050
2018-02-25 08:23:57.548 UTC [channelCmd] InitCmdFactory -> INFO 003 Endorser and orderer connections initialized 2018-02-25 08:23:57.626 UTC [channelCmd] InitCmdFactory -> INFO 019 Endorser and orderer connections initialized 2018-02-25 08:23:57.834 UTC [channelCmd] readBlock -> INFO 020 Received block: 0 2018-02-25 08:23:57.835 UTC [main] main -> INFO 021 Exiting.....
```
Block 0 is returned indicating that the channel has been successfully created.
Here's an example of the peer channel create command option.
- Create a new channel
mychannelfor the network, using the orderer at ip addressorderer.example.com:7050. The configuration update transaction required to create this channel is defined the file./createchannel.tx. Wait 30 seconds for the channel to be created.
``` peer channel create -c mychannel --orderer orderer.example.com:7050 -f ./createchannel.tx -t 30s
2018-02-23 06:31:58.568 UTC [channelCmd] InitCmdFactory -> INFO 003 Endorser and orderer connections initialized
2018-02-23 06:31:58.669 UTC [channelCmd] InitCmdFactory -> INFO 019 Endorser and orderer connections initialized
2018-02-23 06:31:58.877 UTC [channelCmd] readBlock -> INFO 020 Received block: 0
2018-02-23 06:31:58.878 UTC [main] main -> INFO 021 Exiting.....
ls -l
-rw-r--r-- 1 root root 11982 Feb 25 12:24 mychannel.block
```
You can see that channel mychannel has been successfully created, as
indicated in the output where block 0 (zero) is added to the blockchain for
this channel and returned to the peer, where it is stored in the local
directory as mychannel.block.
Block zero is often called the genesis block as it provides the starting configuration for the channel. All subsequent updates to the channel will be captured as configuration blocks on the channel's blockchain, each of which supersedes the previous configuration.
peer channel fetch example
Here's some examples of the peer channel fetch command.
- Using the
newestoption to retrieve the most recent channel block, and store it in the filemychannel.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.....
ls -l
-rw-r--r-- 1 root root 11982 Feb 25 13:10 mychannel.block
```
You can see that the retrieved block is number 32, and that the information
has been written to the file mychannel.block.
- Using the
(block number)option to retrieve a specific block -- in this case, block number 16 -- and store it in the default block file.
``` 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.....
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
```
You can see that the retrieved block is number 16, and that the information
has been written to the default file mychannel_16.block.
For configuration blocks, the block file can be decoded using the
configtxlator command. See this command for an example
of decoded output. User transaction blocks can also be decoded, but a user
program must be written to do this.
peer channel getinfo example
Here's an example of the peer channel getinfo command.
- Get information about the local peer for channel
mychannel.
``` peer channel getinfo -c mychannel
2018-02-25 15:15:44.135 UTC [channelCmd] InitCmdFactory -> INFO 003 Endorser and orderer connections initialized Blockchain info: {"height":5,"currentBlockHash":"JgK9lcaPUNmFb5Mp1qe1SVMsx3o/22Ct4+n5tejcXCw=","previousBlockHash":"f8lZXoAn3gF86zrFq7L1DzW2aKuabH9Ow6SIE5Y04a4="} 2018-02-25 15:15:44.139 UTC [main] main -> INFO 006 Exiting.....
```
You can see that the latest block for channel mychannel is block 5. You
can also see the cryptographic hashes for the most recent blocks in the
channel's blockchain.
peer channel join example
Here's an example of the peer channel join command.
- Join a peer to the channel defined in the genesis block identified by the file
./mychannel.genesis.block. In this example, the channel block was previously retrieved by thepeer channel fetchcommand.
``` peer channel join -b ./mychannel.genesis.block
2018-02-25 12:25:26.511 UTC [channelCmd] InitCmdFactory -> INFO 003 Endorser and orderer connections initialized 2018-02-25 12:25:26.571 UTC [channelCmd] executeJoin -> INFO 006 Successfully submitted proposal to join channel 2018-02-25 12:25:26.571 UTC [main] main -> INFO 007 Exiting.....
```
You can see that the peer has successfully made a request to join the channel.
peer channel list example
Here's an example of the peer channel list command.
-
List the channels to which a peer is joined.
``` peer channel list
2018-02-25 14:21:20.361 UTC [channelCmd] InitCmdFactory -> INFO 003 Endorser and orderer connections initialized Channels peers has joined: mychannel 2018-02-25 14:21:20.372 UTC [main] main -> INFO 006 Exiting.....
```
You can see that the peer is joined to channel
mychannel.
peer channel signconfigtx example
Here's an example of the peer channel signconfigtx command.
- Sign the
channel updatetransaction defined in the file./updatechannel.tx. The example lists the configuration transaction file before and after the command.
``` ls -l
-rw-r--r-- 1 anthonyodowd staff 284 25 Feb 18:16 updatechannel.tx
peer channel signconfigtx -f updatechannel.tx
2018-02-25 18:16:44.456 GMT [channelCmd] InitCmdFactory -> INFO 001 Endorser and orderer connections initialized 2018-02-25 18:16:44.459 GMT [main] main -> INFO 002 Exiting.....
ls -l
-rw-r--r-- 1 anthonyodowd staff 2180 25 Feb 18:16 updatechannel.tx
```
You can see that the peer has successfully signed the configuration
transaction by the increase in the size of the file updatechannel.tx from
284 bytes to 2180 bytes.
peer channel update example
Here's an example of the peer channel update command.
- Update the channel
mychannelusing the configuration transaction defined in the file./updatechannel.tx. Use the orderer at ip addressorderer.example.com:7050to send the configuration transaction to all peers in the channel to update their copy of the channel configuration.
``` peer channel update -c mychannel -f ./updatechannel.tx -o orderer.example.com:7050
2018-02-23 06:32:11.569 UTC [channelCmd] InitCmdFactory -> INFO 003 Endorser and orderer connections initialized 2018-02-23 06:32:11.626 UTC [main] main -> INFO 010 Exiting.....
```
At this point, the channel mychannel has been successfully updated.
This work is licensed under a Creative Commons Attribution 4.0 International License.