Implement Single-Binary Visor Using libsui

[karlem]

Rationale
A single-binary Visor that embeds CometBFT, Fendermint, and optional relayer/EVM services simplifies distribution and eliminates the need to manage multiple executables. This approach allows signature checks during unpacking, consolidates node configuration (in visor.toml), and provides a unified CLI for starting, stopping, and logging processes.

Actions

1. Embed Dependencies with libsui

• Bundle CometBFT, Fendermint, and relayer/eth inside the Visor binary.
• Unpack them to a secure or temporary location at runtime, performing signature checks.

2. Implement Initialization

• Add visor init to create ~/.mychain/ and generate default configs (visor.toml, CometBFT, Fendermint, Relayer).
• Provide key generation if necessary.

3. Start/Stop & Logging

• Add visor start to spawn all embedded binaries (CometBFT, Fendermint, Relayer).
• Add visor stop to gracefully terminate processes.
• Direct logs to console or ~/.mychain/logs.

4. Global Configuration

• Store global settings (chain ID, run_relayer, etc.) in visor.toml.
• Pass relevant config to unpacked binaries (e.g., genesis file path, ports).

5. Subcommands

• Provide commands like visor cometbft version or visor fendermint init by proxying to the unpacked binaries for advanced usage.

6. Documentation

• Include a brief guide covering visor init, visor start, visor stop, and any specialized subcommands.

[linear]

IPC-169 Implement Single-Binary Visor Using libsui

[raulk]

I disagree with introducing yet another new thing/layer of complexity here. We need to simplify, not introduce more indirection! Would propose the following approach:

• Consolidate everything into a single ipc process, except for the CLI. ipc-cli can be renamed to ipcctl (following the kube and kubectl convention).
• Repurpose the existing Fendermint config.toml and turn it into an ipc.toml. Extend it to define consensus engine choice (only one choice available today: cometbft) and the consensus engine parameters.
• This ipc.toml is a single configuration that can be used to start any service: consensus, node, eth-api, relayer. So you'd do: ipc run --config=ipc.toml [service_name...].
• We can have predefined profiles, e.g. the default profile could be to start everything within a single process. So if you simply do ipc run --config=ipc.toml, it would start all of the above services. And we can define other profiles going forward, and select with --profile.
• To manage CometBFT, we will want to use Docker. We can repurpose quite a bit of code from the Materializer to do just that.