Relay packets on multiple paths

Hermes can relay packets over all current or future paths between the configured set of chains.

Follow the steps below to connect three chains together and relay packets between them:

Paste the following configuration in the standard Hermes configuration file at ~/.hermes/config.toml:

[global]
log_level = 'info'

[mode]

[mode.clients]
enabled = true
refresh = true
misbehaviour = true

[mode.connections]
enabled = false

[mode.channels]
enabled = false

[mode.packets]
enabled = true
clear_interval = 100
clear_on_start = true
tx_confirmation = true

[[chains]]
id = 'ibc-0'
rpc_addr = 'http://127.0.0.1:26657'
grpc_addr = 'http://127.0.0.1:9090'
websocket_addr = 'ws://127.0.0.1:26657/websocket'
rpc_timeout = '10s'
account_prefix = 'cosmos'
key_name = 'testkey'
store_prefix = 'ibc'
max_gas = 2000000
gas_price = { price = 0.001, denom = 'stake' }
gas_adjustment = 0.1
clock_drift = '5s'
trusting_period = '14days'
trust_threshold = { numerator = '1', denominator = '3' }

[[chains]]
id = 'ibc-1'
rpc_addr = 'http://127.0.0.1:26557'
grpc_addr = 'http://127.0.0.1:9091'
websocket_addr = 'ws://127.0.0.1:26557/websocket'
rpc_timeout = '10s'
account_prefix = 'cosmos'
key_name = 'testkey'
store_prefix = 'ibc'
max_gas = 2000000
gas_price = { price = 0.001, denom = 'stake' }
gas_adjustment = 0.1
clock_drift = '5s'
trusting_period = '14days'
trust_threshold = { numerator = '1', denominator = '3' }

[[chains]]
id = 'ibc-2'
rpc_addr = 'http://127.0.0.1:26457'
grpc_addr = 'http://127.0.0.1:9092'
websocket_addr = 'ws://127.0.0.1:26457/websocket'
rpc_timeout = '10s'
account_prefix = 'cosmos'
key_name = 'testkey'
store_prefix = 'ibc'
max_gas = 2000000
gas_price = { price = 0.001, denom = 'stake' }
gas_adjustment = 0.1
clock_drift = '5s'
trusting_period = '14days'
trust_threshold = { numerator = '1', denominator = '3' }

This configuration has three chains ibc-0, ibc-1 and ibc-2.

Run the dev-env script with the parameters below to start three chains:
```
./scripts/dev-env ~/.hermes/config.toml ibc-0 ibc-1 ibc-2
```
NOTE: The script will prompt you to delete the data folder, double check the path and if it points to the data directory in the current directory, answer 'yes'.

The script configures and starts three gaiad instances, named ibc-0, and ibc-1, and ibc-2.

Create a channel between ibc-0 and ibc-1. Since this is the first time we're connecting these two chains, we'll need to spin up a client and a connection between them as well. The create channel command gives us the convenient option to create a client and a connection. Keep in mind that this is not the default behavior of create channel, but in this case we're making an exception. Execute the following command:

hermes create channel ibc-0 --chain-b ibc-1 --port-a transfer --port-b transfer --new-client-connection

Then respond 'yes' to the prompt that pops up. Once the command has run to completion, you should see the following among the output logs:

(...)

Success: Channel {
    ordering: Unordered,
    a_side: ChannelSide {
        chain: ProdChainHandle {
            chain_id: ChainId {
                id: "ibc-0",
                version: 0,
            },
            runtime_sender: Sender { .. },
        },
        client_id: ClientId(
            "07-tendermint-0",
        ),
        connection_id: ConnectionId(
            "connection-0",
        ),
        port_id: PortId(
            "transfer",
        ),
        channel_id: ChannelId(
            "channel-0",
        ),
    },
    b_side: ChannelSide {
        chain: ProdChainHandle {
            chain_id: ChainId {
                id: "ibc-1",
                version: 1,
            },
            runtime_sender: Sender { .. },
        },
        client_id: ClientId(
            "07-tendermint-0",
        ),
        connection_id: ConnectionId(
            "connection-0",
        ),
        port_id: PortId(
            "transfer",
        ),
        channel_id: ChannelId(
            "channel-0",
        ),
    },
    connection_delay: 0s,
    version: Some(
        "ics20-1",
    ),
}

Note that the channel identifier on both ibc-0 and ibc-1 is channel-0.

Create a channel between ibc-1 and ibc-2 using the structure of the previous invocation we used to create a channel between ibc-0 and ibc-1:

hermes create channel ibc-1 --chain-b ibc-2 --port-a transfer --port-b transfer --new-client-connection

(...)

Success: Channel {
    ordering: Unordered,
    a_side: ChannelSide {
        chain: ProdChainHandle {
            chain_id: ChainId {
                id: "ibc-1",
                version: 1,
            },
            runtime_sender: Sender { .. },
        },
        client_id: ClientId(
            "07-tendermint-1",
        ),
        connection_id: ConnectionId(
            "connection-1",
        ),
        port_id: PortId(
            "transfer",
        ),
        channel_id: ChannelId(
            "channel-1",
        ),
    },
    b_side: ChannelSide {
        chain: ProdChainHandle {
            chain_id: ChainId {
                id: "ibc-2",
                version: 2,
            },
            runtime_sender: Sender { .. },
        },
        client_id: ClientId(
            "07-tendermint-0",
        ),
        connection_id: ConnectionId(
            "connection-0",
        ),
        port_id: PortId(
            "transfer",
        ),
        channel_id: ChannelId(
            "channel-0",
        ),
    },
    connection_delay: 0s,
    version: Some(
        "ics20-1",
    ),
}

Note that the channel identifier on ibc-1 is channel-1, and on ibc-2 it is channel-0.

Start Hermes using the start command:
```
hermes start
```
Hermes will first relay the pending packets that have not been relayed and then start passive relaying by listening to and acting on packet events.

In a separate terminal, use the ft-transfer command to send:

Two packets from ibc-0 to ibc-1 from source channel channel-0

hermes tx raw ft-transfer ibc-1 ibc-0 transfer channel-0 9999 -o 1000 -n 2

Success: [
    SendPacket(
        SendPacket {
            height: revision: 0, height: 3056,
            packet: PortId("transfer") ChannelId("channel-0") Sequence(3),
        },
    ),
    SendPacket(
        SendPacket {
            height: revision: 0, height: 3056,
            packet: PortId("transfer") ChannelId("channel-0") Sequence(4),
        },
    ),
]

Two packets from ibc-1 to ibc-2 from source channel channel-1

hermes tx raw ft-transfer ibc-2 ibc-1 transfer channel-1 9999 -o 1000 -n 2

Success: [
    SendPacket(
        SendPacket {
            height: revision: 1, height: 3076,
            packet: PortId("transfer") ChannelId("channel-1") Sequence(3),
        },
    ),
    SendPacket(
        SendPacket {
            height: revision: 1, height: 3076,
            packet: PortId("transfer") ChannelId("channel-1") Sequence(4),
        },
    ),
]

Observe the output on the relayer terminal, verify that the send events are processed, and that the recv_packets are sent out.

(...)

INFO ibc_relayer::link: [ibc-0 -> ibc-1] result events:
    UpdateClientEv(ev_h:1-3048, 07-tendermint-0(0-3057), )
    WriteAcknowledgementEv(h:1-3048, seq:3, path:channel-0/transfer->channel-0/transfer, toh:1-4045, tos:0))
    WriteAcknowledgementEv(h:1-3048, seq:4, path:channel-0/transfer->channel-0/transfer, toh:1-4045, tos:0))
INFO ibc_relayer::link: [ibc-0 -> ibc-1] success

(...)

INFO ibc_relayer::link: [ibc-1 -> ibc-0] clearing old packets
INFO ibc_relayer::link: [ibc-1 -> ibc-0] received from query_txs []
INFO ibc_relayer::link: [ibc-1 -> ibc-0] finished clearing pending packets
INFO ibc_relayer::link: [ibc-1 -> ibc-0] generate messages from batch with 2 events
INFO ibc_relayer::link: [ibc-1 -> ibc-0] scheduling op. data with 2 msg(s) for Destination chain (height 1-3049)
INFO ibc_relayer::link: [ibc-1 -> ibc-0] relay op. data to Destination, proofs height 1-3048, (delayed by: 2.154603ms) [try 1/10]
INFO ibc_relayer::link: [ibc-1 -> ibc-0] prepending Destination client update @ height 1-3049
INFO ibc_relayer::link: [ibc-1 -> ibc-0] assembled batch of 3 message(s)
INFO ibc_relayer::link: [ibc-1 -> ibc-0] result events:
    UpdateClientEv(ev_h:0-3059, 07-tendermint-0(1-3049), )
    AcknowledgePacketEv(h:0-3059, seq:3, path:channel-0/transfer->channel-0/transfer, toh:1-4045, tos:0))
    AcknowledgePacketEv(h:0-3059, seq:4, path:channel-0/transfer->channel-0/transfer, toh:1-4045, tos:0))
INFO ibc_relayer::link: [ibc-1 -> ibc-0] success

(...)

Query the unreceived packets and acknowledgments on ibc-1 and ibc-2 from a different terminal:

hermes query packet unreceived-packets ibc-1 transfer channel-0
hermes query packet unreceived-acks ibc-0 transfer channel-0
hermes query packet unreceived-packets ibc-2 transfer channel-0
hermes query packet unreceived-acks ibc-1 transfer channel-1

If everything went well, each of these commands should result in:

Success: []

Hermes (IBC Relayer CLI) Documentation

Relay packets on multiple paths