How to enable chain extensions?

Question

I have a chain extension implemented on substrate-contracts-node and in my ink! smart contract according to this tutorial. When I try to instantiate my contract on a local contracts-ui I get the following message:

module uses chain extensions but chain extensions are disabled

What do I need to do to enable chain extensions?

Here is my code for sanity check.

Answer 1

Make sure you have type ChainExtension defined in your runtime:

impl pallet_contracts::Config for Runtime {
    ....
    type ChainExtension = FetchRandomExtension;
}

...as indicated in the docs:

• https://github.com/paritytech/ink/tree/v3.0.0-rc8/examples/rand-extension#chain-side-integration

Also remember that there are two ways of running the substrate-contracts-node:

1. Cloning it, modifying it, building it, running it:

git clone https://github.com/paritytech/substrate-contracts-node
cd substrate-contracts-node
cargo run --release -- --dev

OR

2. Using cargo install and just running it:

cargo install contracts-node --git https://github.com/paritytech/substrate-contracts-node.git --force --locked
substrate-contracts-node --dev

Turns out I was modifying my code and running my node using the second option (which was a completely different install!) 🤦