Use a stock BusyBox for the Docker Integration

gns3server/compute/docker/docker_vm.py

@@ -574,15 +574,9 @@ 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",
+                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,

gns3server/compute/docker/resources/bin/udhcpc

@@ -0,0 +1,8 @@
+#!/gns3/bin/busybox sh
+
+SCRIPT="/gns3/etc/udhcpc/default.script"
+EXTRA=""
+
+[ "$(cat "/proc/$PPID/comm" 2>/dev/null)" = ifup ] && EXTRA="-t 3 -T 2 -A 1 -b"
+
+exec /tmp/gns3/bin/udhcpc -s "$SCRIPT" $EXTRA "$@"