🧱 Midnight Proof Server with Pre-Baked ZK Params

🔍 Motivation

The default midnightnetwork/proof-server container attempts to download ZK parameter files from the internet on startup. This behavior can be unreliable or problematic in certain contexts due to:

• ⚙️ Limited or non-interactive environments like CI/CD pipelines where downloads may silently fail
• 🐞 Known bug in the proof server that can cause incomplete or failed downloads
• 📦 Large file sizes: some parameter files (e.g., bls_filecoin_2p24) can be over 3 GB

To avoid these issues, this setup allows you to pre-bake the required parameter files into the container image, ensuring the proof server works reliably in all environments.

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🛠️ How It Works

This setup uses a multi-stage Docker build:

1. First stage (alpine) downloads the required zk parameter files from S3.
2. Final image (midnightnetwork/proof-server) copies the files into /.cache/midnight/zk-params.

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🔧 Configuration

Build Arguments

Arg Name	Description
PROOF_SERVER_VERSION	Version of the midnightnetwork/proof-server base image (default: 4.0.0)
CIRCUIT_PARAM_RANGE	Space-separated range of circuit IDs to download (e.g., "10 11 12 13 14 15 16 17")

⚠️ Note: Maximum value for circuit param is currently 24.
Circuit 24 file is ~3 GB, so only include what's needed for your use case.

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🏗️ How to Build

docker build \
  --build-arg PROOF_SERVER_VERSION=4.0.0 \
  --build-arg CIRCUIT_PARAM_RANGE="10 11 12 13 14 15" \
  -t midnight-proof-server:prebaked .

Alternative: Manual Download + Volume Mount

If you'd rather not bake the files into the image (e.g., to save image size), you can:

Download the files manually:

./fetch-zk-params.sh

Then run the proof server with a volume mount:

docker run \c
  --name midnight-proof-server \
  -p 6300:6300 \
  -v $(pwd)/.cache/midnight/zk-params:/.cache/midnight/zk-params \
  midnightnetwork/proof-server:4.0.0