fix: add nim libp2p echo interop

Author: AkMo3

pyproject.toml

@@ -20,6 +20,7 @@ dependencies = [
     "base58>=1.0.3",
     "coincurve==21.0.0",
     "exceptiongroup>=1.2.0; python_version < '3.11'",
+    "fastecdsa==2.3.2; sys_platform != 'win32'",
     "grpcio>=1.41.0",
     "lru-dict>=1.1.6",
     "multiaddr (>=0.0.9,<0.0.10)",
@@ -32,7 +33,6 @@ dependencies = [
     "rpcudp>=3.0.0",
     "trio-typing>=0.0.4",
     "trio>=0.26.0",
-    "fastecdsa==2.3.2; sys_platform != 'win32'",
     "zeroconf (>=0.147.0,<0.148.0)",
 ]
 classifiers = [
@@ -282,4 +282,5 @@ project_excludes = [
     "**/*pb2.py",
     "**/*.pyi",
     ".venv/**",
+    "./tests/interop/nim_libp2p",
 ]

tests/interop/nim_libp2p/.gitignore

@@ -0,0 +1,8 @@
+nimble.develop
+nimble.paths
+
+*.nimble
+nim-libp2p/
+
+nim_echo_server
+config.nims

tests/interop/nim_libp2p/nim_echo_server.nim

@@ -0,0 +1,108 @@
+{.used.}
+
+import chronos
+import stew/byteutils
+import libp2p
+
+##
+# Simple Echo Protocol Implementation for py-libp2p Interop Testing
+##
+const EchoCodec = "/echo/1.0.0"
+
+type EchoProto = ref object of LPProtocol
+
+proc new(T: typedesc[EchoProto]): T =
+  proc handle(conn: Connection, proto: string) {.async: (raises: [CancelledError]).} =
+    try:
+      echo "Echo server: Received connection from ", conn.peerId
+
+      # Read and echo messages in a loop
+      while not conn.atEof:
+        try:
+          # Read length-prefixed message using nim-libp2p's readLp
+          let message = await conn.readLp(1024 * 1024) # Max 1MB
+          if message.len == 0:
+            echo "Echo server: Empty message, closing connection"
+            break
+
+          let messageStr = string.fromBytes(message)
+          echo "Echo server: Received (", message.len, " bytes): ", messageStr
+
+          # Echo back using writeLp
+          await conn.writeLp(message)
+          echo "Echo server: Echoed message back"
+
+        except CatchableError as e:
+          echo "Echo server: Error processing message: ", e.msg
+          break
+
+    except CancelledError as e:
+      echo "Echo server: Connection cancelled"
+      raise e
+    except CatchableError as e:
+      echo "Echo server: Exception in handler: ", e.msg
+    finally:
+      echo "Echo server: Connection closed"
+      await conn.close()
+
+  return T.new(codecs = @[EchoCodec], handler = handle)
+
+##
+# Create QUIC-enabled switch
+##
+proc createSwitch(ma: MultiAddress, rng: ref HmacDrbgContext): Switch =
+  var switch = SwitchBuilder
+    .new()
+    .withRng(rng)
+    .withAddress(ma)
+    .withQuicTransport()
+    .build()
+  result = switch
+
+##
+# Main server
+##
+proc main() {.async.} =
+  let
+    rng = newRng()
+    localAddr = MultiAddress.init("/ip4/0.0.0.0/udp/0/quic-v1").tryGet()
+    echoProto = EchoProto.new()
+
+  echo "=== Nim Echo Server for py-libp2p Interop ==="
+
+  # Create switch
+  let switch = createSwitch(localAddr, rng)
+  switch.mount(echoProto)
+
+  # Start server
+  await switch.start()
+
+  # Print connection info
+  echo "Peer ID: ", $switch.peerInfo.peerId
+  echo "Listening on:"
+  for addr in switch.peerInfo.addrs:
+    echo "  ", $addr, "/p2p/", $switch.peerInfo.peerId
+  echo "Protocol: ", EchoCodec
+  echo "Ready for py-libp2p connections!"
+  echo ""
+
+  # Keep running
+  try:
+    await sleepAsync(100.hours)
+  except CancelledError:
+    echo "Shutting down..."
+  finally:
+    await switch.stop()
+
+# Graceful shutdown handler
+proc signalHandler() {.noconv.} =
+  echo "\nShutdown signal received"
+  quit(0)
+
+when isMainModule:
+  setControlCHook(signalHandler)
+  try:
+    waitFor(main())
+  except CatchableError as e:
+    echo "Error: ", e.msg
+    quit(1)

tests/interop/nim_libp2p/scripts/setup_nim_echo.sh

@@ -0,0 +1,98 @@
+#!/usr/bin/env bash
+# Simple setup script for nim echo server interop testing
+
+set -euo pipefail
+
+# Colors
+GREEN='\033[0;32m'
+RED='\033[0;31m'
+YELLOW='\033[1;33m'
+NC='\033[0m'
+
+log_info() { echo -e "${GREEN}[INFO]${NC} $1"; }
+log_warn() { echo -e "${YELLOW}[WARN]${NC} $1"; }
+log_error() { echo -e "${RED}[ERROR]${NC} $1"; }
+
+SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+PROJECT_ROOT="${SCRIPT_DIR}/.."
+NIM_LIBP2P_DIR="${PROJECT_ROOT}/nim-libp2p"
+
+# Check prerequisites
+check_nim() {
+    if ! command -v nim &> /dev/null; then
+        log_error "Nim not found. Install with: curl -sSf https://nim-lang.org/choosenim/init.sh | sh"
+        exit 1
+    fi
+    if ! command -v nimble &> /dev/null; then
+        log_error "Nimble not found. Please install Nim properly."
+        exit 1
+    fi
+}
+
+# Setup nim-libp2p dependency
+setup_nim_libp2p() {
+    log_info "Setting up nim-libp2p dependency..."
+
+    if [ ! -d "${NIM_LIBP2P_DIR}" ]; then
+        log_info "Cloning nim-libp2p..."
+        git clone https://github.com/status-im/nim-libp2p.git "${NIM_LIBP2P_DIR}"
+    fi
+
+    cd "${NIM_LIBP2P_DIR}"
+    log_info "Installing nim-libp2p dependencies..."
+    nimble install -y --depsOnly
+}
+
+# Build nim echo server
+build_echo_server() {
+    log_info "Building nim echo server..."
+
+    cd "${PROJECT_ROOT}"
+
+    # Create nimble file if it doesn't exist
+    cat > nim_echo_test.nimble << 'EOF'
+# Package
+version = "0.1.0"
+author = "py-libp2p interop"
+description = "nim echo server for interop testing"
+license = "MIT"
+
+# Dependencies
+requires "nim >= 1.6.0"
+requires "libp2p"
+requires "chronos"
+requires "stew"
+
+# Binary
+bin = @["nim_echo_server"]
+EOF
+
+    # Build the server
+    log_info "Compiling nim echo server..."
+    nim c -d:release -d:chronicles_log_level=INFO -d:libp2p_quic_support --opt:speed --gc:orc -o:nim_echo_server nim_echo_server.nim
+
+    if [ -f "nim_echo_server" ]; then
+        log_info "✅ nim_echo_server built successfully"
+    else
+        log_error "❌ Failed to build nim_echo_server"
+        exit 1
+    fi
+}
+
+main() {
+    log_info "Setting up nim echo server for interop testing..."
+
+    # Create logs directory
+    mkdir -p "${PROJECT_ROOT}/logs"
+
+    # Clean up any existing processes
+    pkill -f "nim_echo_server" || true
+
+    check_nim
+    setup_nim_libp2p
+    build_echo_server
+
+    log_info "🎉 Setup complete! You can now run: python -m pytest test_echo_interop.py -v"
+}
+
+main "$@"