Start other network without forking

[yihuang]

Proposal: Run other networks without forking

Current behavior: Several chain parameters are static constants, not easy to change if not fork or significant copy-paste code.

Desired behavior: easy to start another network by import ethermint as a module

Use case: start other network with ethermint codebase.

Approach 1

New network re-use the whole ethermint scaffolding, just make some constants customizable, mainly these things.

Approach 2

New network start with cosmos-sdk simapp standard scaffolding, possibly with it's own customization, only add necessary stuff for ethermint to run, mainly:

• add evm module
• custom ante handler
• extra app configuration (evm-rpc listen addresses)
• start evm rpc server in cli start command
• anything else?

[leejw51crypto]

how about approach 1,
what's the benefit of approach 2 ?

[yihuang]

how about approach 1,
what's the benefit of approach 2 ?

with approach 2, we would be more clear on what changes ethermint does on top of cosmos-sdk standard scaffolding, currently ethermint scaffolding is significantly different from cosmos-sdk one, I'm not sure which part is necessary which part is accidental. With this approach we can also do our own customization, for example add other native modules.

Actually I'd like to try approach 2, and record the change list we have to do for ethermint to run.

[fedekunze]

Several chain parameters are static constants, not easy to change if not fork or significant copy-paste code.

what are the chain parameters that you would like to change?

[yihuang]

Several chain parameters are static constants, not easy to change if not fork or significant copy-paste code.

what are the chain parameters that you would like to change?

Normally just these things https://github.com/tharsis/ethermint/blob/main/app/app.go#L109:

• address prefix
• bip44 coin type
• default home directory name

But for the testnet, we decide not change, the decision for the mainnet is not made yet.
There's also possibility that we might want to add new native modules in the future though.

[fedekunze]

Normally just these things https://github.com/tharsis/ethermint/blob/main/app/app.go#L109:

but you can change those by defining them in your app.go, you just need to define your prefix and home directory. The approach 2 is what chains would usually use when importing external modules

[yihuang]

Normally just these things https://github.com/tharsis/ethermint/blob/main/app/app.go#L109:

but you can change those by defining them in your app.go, you just need to define your prefix and home directory. The approach 2 is what chains would usually use when importing external modules

Do you mean embed the EthermintApp and override some methods?

Another issue is the cli commands is defined in main package, which seems to be not importable.