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https://github.com/GNS3/gns3-server.git
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IOL derives interface MACs from its application ID. With a constant local-app every node shared the same MACs, and linked routers dropped each other's frames as MAC loops — ARP never resolved and pings were 100% lost even though the whole uBridge datapath was forwarding. Derive local-app from the node UUID (stable across restarts, kept in 1..1022) and align remote-app with the netiomux convention CML uses (1023). Verified end to end: two iol-xe nodes, Ethernet0/0 link, ARP resolves both ways, ping 4/5 (first loss = ARP), graceful stop/start keeps the NVRAM config.
221 lines
9.1 KiB
Python
221 lines
9.1 KiB
Python
#
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# Copyright (C) 2025 GNS3 Technologies Inc.
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#
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# This program is free software: you can redistribute it and/or modify
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# it under the terms of the GNU General Public License as published by
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# the Free Software Foundation, either version 3 of the License, or
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# (at your option) any later version.
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#
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# This program is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU General Public License for more details.
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#
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# You should have received a copy of the GNU General Public License
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# along with this program. If not, see <http://www.gnu.org/licenses/>.
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"""
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IOL (IOS on Linux) Docker container subclass.
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Supports IOL images packaged with Cisco CML's container runner
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(``iol-runner``, ``virl.lab/cmd/iol-runner``), e.g. ``iol-xe/iol-xe:17-18-02``:
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a scratch image whose ENTRYPOINT is ``iol-runner -config /config/iol-config.json
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-stdio``. The runner generates the license, writes the NETMAP, manages NVRAM
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and muxes the IOS console onto PID 1 stdio (works with the plain ``telnet``
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console type; requires a TTY, which GNS3 always allocates).
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Networking does not use the container's network namespace at all: the runner's
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netiomux exposes per-interface AF_UNIX datagram sockets in the container's
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``/tmp`` (``s%02d.sock`` receive, ``c%02d.sock`` send — raw Ethernet frames),
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wired by the generic ``GNS3_UNIX_SOCKET_NIO`` capability of VendorDockerVM
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(uBridge reaches them through a per-node runtime directory bound at /tmp —
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see ``VendorDockerVM._unix_socket_host_dir``). The local application ID is
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derived from the node ID so that linked nodes get distinct MACs.
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This class is selected by the ``GNS3_IOL_RUNNER=1`` environment marker.
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"""
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import contextlib
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import glob
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import json
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import logging
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import os
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import shutil
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from gns3server.compute.adapters.ethernet_adapter import EthernetAdapter
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from gns3server.compute.docker.docker_error import DockerHttp404Error
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from gns3server.compute.docker.docker_vm import DockerVM
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from gns3server.compute.docker.vendor_docker_vm import VendorDockerVM
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log = logging.getLogger(__name__)
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class IOLDockerVM(VendorDockerVM):
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"""
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VendorDockerVM subclass for iol-runner images.
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Extra opt-in knob (beyond the inherited vendor ones):
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* ``GNS3_IOL_MEMORY=<MB>`` — IOL router memory passed via the generated
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config (default 2048). The template ``memory`` field caps the whole
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container: keep it at IOL memory + ~512 MB headroom or the kernel
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OOM-killer will fire.
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The marker itself forces ``GNS3_SKIP_INIT`` and the unix-socket NIO wiring,
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and auto-adds the ``/config`` and ``/tmp/run`` persistent volumes, so a
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template containing only ``GNS3_IOL_RUNNER=1`` is fully configured.
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"""
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_IOL_CONFIG_DIR = "/config"
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_IOL_RUN_DIR = "/tmp/run"
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def _parse_vendor_environment(self):
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super()._parse_vendor_environment()
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# The image has no shell (scratch): init.sh could neither run (its
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# #!/bin/sh shebang doesn't exist) nor wait for eth interfaces that
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# are never created. The console is IOS itself on PID 1 stdio.
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self._gns3_init = False
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self._unix_socket_nio = True
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self._unix_socket_dir = "/tmp"
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self._iol_memory = 2048
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if self._environment:
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for _line in self._environment.splitlines():
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_line = _line.strip().rstrip(",")
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if _line.startswith("GNS3_IOL_MEMORY="):
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try:
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memory = int(_line.split("=", 1)[1].strip())
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if memory > 0:
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self._iol_memory = memory
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except ValueError:
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pass
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@DockerVM.adapters.setter
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def adapters(self, adapters):
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"""
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Override: one IOL adapter is a 4-port unit — the IOU model. The
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template's adapter count is the number of units (2 adapters =
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Ethernet0/0-3 + Ethernet1/0-3); the generated config asks the runner
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for adapters × 4 interfaces and links address ports as
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(adapter_number, port_number 0-3).
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"""
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if len(self._ethernet_adapters) == adapters:
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return
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self._ethernet_adapters.clear()
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for _ in range(0, adapters):
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self._ethernet_adapters.append(EthernetAdapter(interfaces=4))
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log.debug(
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"IOL container '%s': number of 4-port Ethernet adapters set to %d",
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self._name, adapters,
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)
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def _persistent_volume_list(self, image_info, include_network_config=True):
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"""
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Override: the runner requires ``/config`` (its config file, generated
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below) and ``/tmp/run`` (its working directory: startup-config and
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NVRAM live there — NETMAP and the netiomux sockets are ephemeral and
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stay in the container's own /tmp). Auto-add both so a minimal
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template cannot be misconfigured.
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"""
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volumes = super()._persistent_volume_list(image_info, include_network_config)
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for needed in (self._IOL_CONFIG_DIR, self._IOL_RUN_DIR):
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if not any(needed == v or needed.startswith(v.rstrip("/") + "/") for v in volumes):
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volumes.append(needed)
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return volumes
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async def start(self):
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await self._prepare_iol_runtime()
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await super().start()
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async def restart(self):
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"""
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Override: the base restart is a bare ``docker restart`` — the runner
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would read a stale config (no adapter-count/memory refresh) and
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uBridge would keep wiring to the previous run's sockets. Stop
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gracefully (SIGTERM lets the runner flush NVRAM) and start again.
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"""
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await self.stop(graceful=True)
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await self.start()
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async def _prepare_iol_runtime(self):
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"""
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Regenerate the node's runtime files before the container starts:
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* ``<working_dir>/tmp/run/`` must exist or the IOL process dies at
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boot (the runner writes NETMAP there but does not create it).
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* ``<working_dir>/config/iol-config.json`` is rewritten on every
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start so adapter-count and memory changes take effect.
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* Sockets and netio bus directories left in the wiring directory by a
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previous (possibly SIGKILLed) run are removed — the runner rebinds
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them on boot and would fail on a stale file.
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``tmp/run`` (startup-config, NVRAM) is never touched. Neither is
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anything while the container is already running (idempotent start of
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a live node: the sockets belong to the running runner).
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"""
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try:
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state = await self._get_container_state()
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except DockerHttp404Error:
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state = "stopped"
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os.makedirs(os.path.join(self.working_dir, "tmp", "run"), exist_ok=True)
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self._write_iol_config()
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if state == "running":
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return
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wiring_dir = self._unix_socket_wiring_dir()
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for pattern in ("s??.sock", "c??.sock"):
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for stale in glob.glob(os.path.join(wiring_dir, pattern)):
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with contextlib.suppress(OSError):
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os.unlink(stale)
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for netio_dir in glob.glob(os.path.join(wiring_dir, "netio*")):
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shutil.rmtree(netio_dir, ignore_errors=True)
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def _write_iol_config(self):
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"""
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Write the runner's config file on the host side of the /config volume.
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The runner drops to user-id/group-id after its setup, so everything it
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creates is owned by the server user — which is also what lets the
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(unprivileged) uBridge write into the node's socket directory.
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"""
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config = {
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"binary": "/binary.iol",
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"memory": self._iol_memory,
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"num-eth": self.adapters * 4, # every adapter is a 4-port unit
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"num-serial": 0, # GNS3 docker adapters are ethernet-only
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# IOL derives interface MACs from the local application ID
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# (aabb.cc00.0<app><iface>0); every node needs a distinct one or
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# linked routers share MACs and drop each other's frames as loops.
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# Derived from the node ID: stable across restarts, unique enough
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# (CML allocates per-lab sequential IDs for the same reason).
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"local-app": int(self.id.replace("-", ""), 16) % 1022 + 1,
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"remote-app": 1023, # netiomux's fake peer application ID
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"user-id": os.getuid(),
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"group-id": os.getgid(),
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}
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config_file = os.path.join(self.working_dir, "config", "iol-config.json")
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os.makedirs(os.path.dirname(config_file), exist_ok=True)
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with open(config_file, "w", encoding="utf-8") as f:
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json.dump(config, f, indent=2)
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f.write("\n")
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log.debug("Wrote iol-runner config for '%s': %s", self._name, config)
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async def _fix_permissions(self):
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"""
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Override: no-op. The generated config maps the runner to the server's
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uid/gid, so no root-owned files ever appear in the volumes, and this
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image has no shell for the container-side busybox pass anyway.
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"""
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self._permissions_fixed = True
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