Add Docker Image with localnet nodes

[basfroman]

Included

• added Dockerfile-localnet file for creating image with localnet subtensor nodes (fast and non-fast-blocks available)
• added workflow to build and push subtensor-localnet docker image (for devnet-ready ONLY) after PR merged
• added workflow for checking the ability to build (each commit)

Usage:

docker run --rm --name localnet -p 9944:9944 -p 9945:9945 ghcr.io/opentensor/subtensor-localnet:latest

Also, you can add False in the end of the command to run non-fast-blocks mode

Then just use bittensor

import bittensor as bt

sub = bt.Subtensor("local")

print(sub.block)

To kill the container use:

docker kill localnet

This image already uploaded to https://github.com/opentensor/subtensor/pkgs/container/subtensor-localnet

Test branch based on devnet-ready: subtensor/devnet-ready-with-nodes

Based on this image, I have e2e test improvement https://github.com/opentensor/bittensor/actions/runs/13868150021/job/38811064879

All tests take 5 minutes (instead of 40-45 used to), just bc one test execute with non-fast-block chain node. Another tests take ~1.5 minutes.