Pin nim-libp2p v2.1.0 + Shadow self-IP for v2.1.0 regression

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

nim-test-node/regression/env.nim

@@ -1,11 +1,25 @@
 import strutils, os, osproc
 import chronos, metrics/chronos_httpserver, chronicles
-from nativesockets import getHostname
+from nativesockets import getHostname, getHostByName
 
 type
   NodeType* = enum
     RoleBootstrap, RoleNormal
 
+proc shadowSelfIp(hostname: string): string =
+  ## Shadow doesn't expand a 0.0.0.0 listen into a routable address, so
+  ## switch.peerInfo.addrs ends up empty and kad-dht can't advertise a dialable
+  ## address for us. Resolve our own hostname to the Shadow-assigned IP and listen
+  ## on that instead (host names resolve fine inside Shadow).
+  try:
+    for ip in getHostByName(hostname).addrList:
+      if not ip.startsWith("127.") and ip != "0.0.0.0":
+        return ip
+  except CatchableError as e:
+    warn "Could not resolve self IP; falling back to 0.0.0.0",
+      hostname = hostname, error = e.msg
+  return "0.0.0.0"
+
 let
   inShadow* = getEnv("SHADOWENV").cmpIgnoreCase("true") == 0    #If Running for shadow simulator 
   httpPublishPort* = Port(8645)
@@ -24,10 +38,12 @@ proc getPeerDetails*(): Result[(int, int, int, string, string, string, NodeType,
     connectTo = parseInt(getEnv("CONNECTTO", "10"))
     muxer = getEnv("MUXER", "yamux")
     filePath = if inShadow: "../" else: getEnv("FILEPATH", "./")
+    # k8s expands 0.0.0.0 to the pod IP; Shadow can't, so resolve our own IP there.
+    listenIp = if inShadow: shadowSelfIp(hostname) else: "0.0.0.0"
     address = if muxer.toLowerAscii() == "quic":
-      "/ip4/0.0.0.0/udp/" & $myPort & "/quic-v1"
+      "/ip4/" & listenIp & "/udp/" & $myPort & "/quic-v1"
     else:
-      "/ip4/0.0.0.0/tcp/" & $myPort
+      "/ip4/" & listenIp & "/tcp/" & $myPort
     # RoleNormal + static discovery keep the legacy behaviour when the env is unset.
     nodeRole = parseEnum[NodeType](getEnv("NODE_ROLE", "RoleNormal"))
     discovery = getEnv("DISCOVERY", "static")

nim-test-node/regression/test_node.nimble

@@ -11,5 +11,5 @@ skipDirs      = @[]
 
 requires "nim >= 2.2.0",
           "nimcrypto 0.6.4",
-          "https://github.com/vacp2p/nim-libp2p#26e181e4dd65188051ab4783bcc538ed9579644f", # 2.0.0
+          "https://github.com/vacp2p/nim-libp2p#c470b1146fa2ef23ab88c5a0940923cf7645e9c5", # 2.1.0
           "ggplotnim"