Use a stock BusyBox for the Docker integration

gns3server/compute/docker/docker_vm.py

@@ -520,10 +520,14 @@ class DockerVM(BaseNode):
         # https://github.com/GNS3/gns3-gui/issues/1039
         try:
             process = await asyncio.subprocess.create_subprocess_exec(
-                "docker", "exec", "-i", self._cid, "/gns3/bin/busybox", "script", "-qfc", "while true; do TERM=vt100 /gns3/bin/busybox sh; done", "/dev/null",
+                "script",
+                "-qfc",
+                f"docker exec -i -t {self._cid} /gns3/bin/busybox sh -c 'while true; do TERM=vt100 /gns3/bin/busybox sh; done'",
+                "/dev/null",
                 stdout=asyncio.subprocess.PIPE,
                 stderr=asyncio.subprocess.STDOUT,
-                stdin=asyncio.subprocess.PIPE)
+                stdin=asyncio.subprocess.PIPE
+            )
         except OSError as e:
             raise DockerError("Could not start auxiliary console process: {}".format(e))
         server = AsyncioTelnetServer(reader=process.stdout, writer=process.stdin, binary=True, echo=True)

gns3server/compute/docker/resources/bin/udhcpc

@@ -0,0 +1,15 @@
+#!/gns3/bin/busybox sh
+
+SCRIPT="/gns3/etc/udhcpc/default.script"
+
+if [ "$(cat "/proc/$PPID/comm" 2>/dev/null)" = ifup ]; then
+	# remove "-n" argument
+	for arg do
+		shift
+		[ "$arg" = "-n" ] || set -- "$@" "$arg"
+	done
+	# add default parameters
+	set -- -t 3 -T 2 -A 1 -b "$@"
+fi
+
+exec /tmp/gns3/bin/udhcpc -s "$SCRIPT" "$@"