nerdctl container running in nerdctl reports "subnet 10.4.0.0/24 overlaps with another one on this address space"

[ccureau]

Description

Environment: colima running containerd and nerdctl

I have followed the instructions for building and running nerdctl in docker from the repository README. I do not have docker installed locally because I prefer to use nerdctl for my container needs. When running nerdctl in nerdctl, the following error is reported:

FATA[0000] subnet 10.4.0.0/24 overlaps with other one on this address space

My goal behind this operation is to use nerdctl in a Kubernetes environment, which I do have working with one caveat - I need to enable legacy iptables to make it work.

Steps to reproduce the issue

1. nerdctl build -t nerdctl:latest .
2. nerdctl run --rm -it --privileged nerdctl bash
3. (in nerdctl container) nerdctl run --rm docker.io/hello-world

Describe the results you received and expected

I can't seem to view, add, or change network settings because of the subnet overlap situation.

What version of nerdctl are you using?

current clone from repository (as of 2022-08-08 08:42 ET)

Are you using a variant of nerdctl? (e.g., Rancher Desktop)

Colima

Host information

On host:

Client:
 Namespace:	default
 Debug Mode:	false

Server:
 Server Version: v1.5.8
 Storage Driver: overlayfs
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Plugins:
  Log: json-file
  Storage: native overlayfs
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 5.10.109-0-virt
 Operating System: Alpine Linux v3.14
 OSType: linux
 Architecture: x86_64
 CPUs: 2
 Total Memory: 3.845GiB
 Name: colima
 ID: c9e44533-eb54-4cd7-a0c7-6ae7a136ed94

From container running on host:

Client:
 Namespace:	default
 Debug Mode:	false

Server:
 Server Version: v1.6.8
 Storage Driver: overlayfs
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Cgroup Version: 1
 Plugins:
  Log: fluentd journald json-file
  Storage: native overlayfs stargz
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 5.10.109-0-virt
 Operating System: Ubuntu 22.04.1 LTS
 OSType: linux
 Architecture: x86_64
 CPUs: 2
 Total Memory: 3.845GiB
 Name: 3a5903aac520
 ID: d989f7a6-8d2a-4d1a-8fe8-6212b60ed4e4

[AkihiroSuda]

A custom CIDR can be specified via /etc/cni.d/nerdctl-bridge.conflist (~/.config/cni/net.d/nerdctl-bridge.conflist for rootless)

[astrostl]

user@mac bin % docker run -it --rm ubuntu /bin/bash
FATA[0000] subnet 10.4.0.0/24 overlaps with other one on this address space

I found this issue because I receive an identical error message using the latest Rancher Desktop (which bundles nerdctl). This used to work well. I have upgraded Rancher Desktop and macOS itself since it last worked. I've already tried a 'factory reset' and uninstall/reinstall of Rancher Desktop. I'm using containerd as the runtime.

UPDATE: reverting to Rancher Desktop 1.5.0 from 1.5.1 and performing a second factory reset resolved it for me.