Setting up relayers

Assumptions

We assume that you already have access to Secret and Osmosis nodes (preferably with 21 days of archive and under your own maintentance). These can be either local nodes, or you can access them over the network. However, for networked version, you will need to adjust the systemd configuration not to depend on the chains that are run on other servers. And naturally the hermes configuration needs to adjust the addressing of each chain as well. All nodes should be ran on the same machine, using NVMe drives.

The nodes you use should have the GRPC and Websocket ports open/enabled

The given example has all relayed chains run locally, Secret is on standard ports, other chains are configured as follows:

• Secret: 26657 and 9090

• Osmosis: 26557 and 9091

In these instructions, Hermes is installed under /ibc/hermes, adjust the paths according to your setup. We also install the Go relayer.

These instructions are based on installation on Debian 10, but should work the same on Debian 11 or recent Ubuntu.

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Which software to use - Hermes vs RLY

Hermes

The configuration of Hermes is slightly more involved and has a less intuitive system to pull additional config items from the chain registry as it only replaces and not adds to your config. The allowlist of hermes however is very handy to specify exactly what you want to relay, so as soon as chains are configured adding more channels is a breeze.

Hermes has some problems relaying Wasm channels and startup time can increase a lot if a lot of channels are added using wildcard operators in the config.

The Hermes docs themselves are outstanding and the API utillities in the program allow you to do a lot without ever needing to install the Daemon for any specific chain.

Hermes requires a Grpc and WS endpoint which can be hard to get, especially if relaying with public nodes. their new pull mode helps to reduce this to just RPC though.

Hermes has features to keep Clients of IBC conenctions alive and the Flushing commands work great even when automised. Hermes is also the only software that supports external fee-grants.

RLY

Anecdotally many relayers have said it performs really well, this seems to be specifically the case for ICA and ICQ channels. Adding to that a very intuitive Config which can be added to using 2 simple commands and a PR to the chain registry and it has become quite popular. RLY uses connection based relaying, which means adding config for a connection between 2 chains is a little more work. When added however ALL channels using those clients and connections are relayed meaning no additional config changes when Teams add ICA, ICQ or WASM channels. RLY uses just RPC which makes it a great lightweight version to configurate for a testnet if needed and also simple for mainnet.

Relayers client update tools and flushing automation are very helpful and set up by default however more detailed configs are available if needed. That together with the Commands requiring simple naming (chain registry conventions) instead of chain-ids and Channel numbers makes using the software for maintenance very enjoyable.

The docs of RLY however are quite poor, and although it has a very advanced Fee-grant splitter feature it currently does not support adding fee-grants from addresses not controlled by the relayer themselves.

Hermes - Rust Relayer (Informal Systems)

1. Install Rust Dependencies

You will need rust, build-essential and git installed to follow these instructions:

2. Building Hermes

For preparation, we will create a dedicated user to run Hermes. Following command will also create home directory for the new user.

We will next switch to the hermes user and create a directory where we will compile the relayer software.Open the generated ~/.relayer/config/config.yaml file,

Now is time to clone the source repository and build it. Note that we need to checkout the latest release.

Next we will check that the newly built hermes version is the correct one:

3. Configuring Hermes

Choose your favourite editor and edit the following configuration template to mach your setup. There are features like telemetry and rest API that you can enable, but they are not necessary, so they are left out from this tutorial.

Open config

Edit the config

You can validate the configuration with following:

4. Setting Up Wallets

We will need to create a new wallet, import it, and ultimately fund it. Note the unique derivation paths for secret.

If you want to make sure the keys got imported, you can check them with following command:

5. Testing the setup

Let's do a quick test to see things work properly.

Validate your ~/.hermes/config.toml file by running:

Perform a health check:

You should see a similar output as the one below:

6. Run hermes

Once we see things load up correctly and there are no fatal errors, we can break out of hermes with ctrl-c.

Configuring systemd

Now we will setup hermes to be run by systemd, and to start automatically on reboots.

Create the following configuration to /etc/systemd/system/hermes.service

Then we will start hermes with the newly created service and enable it. Note that this step is done from your normal user account that has sudo privileges, so no longer as hermes.

Go Relayer (RLY) - Strangelove

Make sure you have installed go.

1. Install rly

Clone the repository, checkout the latest stable release and install rly

2. Initialize the config file

Run the following command to initialize the configuration in ~/.relayer/config/config.yaml

3. Configure RLY

To set up the RLY config file You can add the respective channels and chains using the Chain registry queries:

Or open the generated ~/.relayer/config/config.yaml file, and copy-paste the sample configuration below and adjust it to point to the RPC endpoints of your Secret and Osmosis full nodes:

Now you need to add a new key for your relayer or import an existing one to use to sign and relay IBC transactions. Adding a new key happens with the following command:

If you already have a private key and want to restore it from your mnemonic you can use the restore subcommand.

If you specify a different [key-name] from default you would need to edit the config.yaml and change the key parameter value to the label that you’ve chosen.

Start RLY

If your nodes are fully synced, feel free to start the rly daemon: