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:

peer channel

Operate a channel: create|fetch|join|joinbysnapshot|joinbysnapshotstatus|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.
  joinbysnapshot       Joins the peer to a channel by the specified snapshot
  joinbysnapshotstatus Query if joinbysnapshot is running for any 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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes 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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes 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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes 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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes 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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes with the orderer endpoint

peer channel joinbysnapshot

Joins the peer to a channel by the specified snapshot

Usage:
  peer channel joinbysnapshot [flags]

Flags:
  -h, --help                  help for joinbysnapshot
      --snapshotpath string   Path to the snapshot directory

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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes with the orderer endpoint

peer channel joinbysnapshotstatus

Query if joinbysnapshot is running for any channel

Usage:
  peer channel joinbysnapshotstatus [flags]

Flags:
  -h, --help   help for joinbysnapshotstatus

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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes 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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes 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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes 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
      --tlsHandshakeTimeShift duration      The amount of time to shift backwards for certificate expiration checks during TLS handshakes 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.

``` 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.

``` 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.

``` 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.

``` 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.

``` 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.

``` 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 joinbysnapshot example

Here's an example of the peer channel joinbysnapshot command.

``` peer channel joinbysnapshot --snapshotpath /snapshots/completed/testchannel/1000

2020-10-12 11:41:45.442 EDT [channelCmd] InitCmdFactory -> INFO 001 Endorser and orderer connections initialized 2020-10-12 11:41:45.444 EDT [channelCmd] executeJoin -> INFO 002 Successfully submitted proposal to join channel 2020-10-12 11:41:45.444 EDT [channelCmd] joinBySnapshot -> INFO 003 The joinbysnapshot operation is in progress. Use "peer channel joinbysnapshotstatus" to check the status.

```

You can see that the peer has successfully made a request to join the channel from the specified snapshot. When a joinbysnapshot operation is in progress, you cannot run another peer channel join or peer channel joinbysnapshot simultaneously. To know whether or not a joinbysnapshot operation is in progress, you can call the peer channel joinbysnapshotstatus command.

peer channel joinbysnapshotstatus example

Here are some examples of the peer channel joinbysnapshotstatus command.

``` peer channel joinbysnapshotstatus

2020-10-12 11:41:45.952 EDT [channelCmd] InitCmdFactory -> INFO 001 Endorser and orderer connections initialized A joinbysnapshot operation is in progress for snapshot at /snapshots/completed/testchannel/1000 ```

``` peer channel joinbysnapshotstatus

2020-10-12 11:41:47.922 EDT [channelCmd] InitCmdFactory -> INFO 001 Endorser and orderer connections initialized No joinbysnapshot operation is in progress

```

peer channel list example

Here's an example of the peer channel list command.

peer channel signconfigtx example

Here's an example of the peer channel signconfigtx 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.

``` 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.

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