Support for flexible Slirp IP address

[abiosoft]

Description

Lima currently uses the 192.168.5.0/24 subnet and it is currently hardcoded. There should be room for flexibility to accommodate users with a clashing IP address. https://github.com/lima-vm/lima/blob/3ad14f6618f8837a729a79b0ce765beb75f668ab/pkg/qemu/const/const.go#L6

Related Issue: https://github.com/abiosoft/colima/issues/335

[rdgacarvalho]

Hi @abiosoft For networking settings, I am using vmnet as an alternative to manage the IP Range of my cluster (on macOS M1). Have a look at below:

~/.lima/_confi/network.yaml

paths:
  vdeSwitch: /opt/rancher-desktop/bin/vde_switch
  vdeVMNet: /opt/rancher-desktop/bin/vde_vmnet
  varRun: /private/var/run/lima
  sudoers: /private/etc/sudoers.d/lima

group: everyone

networks:
  shared:
    mode: shared
    gateway: 192.168.105.1
    dhcpEnd: 192.168.105.254
    netmask: 255.255.255.0
  bridged:
    mode: bridged
    interface: en0
    # bridged mode doesn't have a gateway; DHCP is managed by the outside network
  host:
    mode: host
    gateway: 192.168.2.1
    dhcpEnd: 192.168.2.254
    netmask: 255.255.255.0

Thus, I am advertising my cluster to use the shared IP. The result is shown below.

kgno -owide

NAME             STATUS   ROLES                       AGE   VERSION        INTERNAL-IP      EXTERNAL-IP      OS-IMAGE       KERNEL-VERSION      CONTAINER-RUNTIME
lima-manager-1   Ready    control-plane,etcd,master   27m   v1.23.6+k3s1   192.168.105.44   192.168.105.44   Ubuntu 21.10   5.13.0-48-generic   containerd://1.5.11-k3s2
lima-manager-2   Ready    control-plane,etcd,master   26m   v1.23.6+k3s1   192.168.105.46   192.168.105.46   Ubuntu 21.10   5.13.0-48-generic   containerd://1.5.11-k3s2
lima-manager-3   Ready    control-plane,etcd,master   23m   v1.23.6+k3s1   192.168.105.47   192.168.105.47   Ubuntu 21.10   5.13.0-48-generic   containerd://1.5.11-k3s2
lima-node-1      Ready    <none>                      22m   v1.23.6+k3s1   192.168.105.34   192.168.105.34   Ubuntu 21.10   5.13.0-48-generic   containerd://1.5.11-k3s2
lima-node-2      Ready    <none>                      21m   v1.23.6+k3s1   192.168.105.37   192.168.105.37   Ubuntu 21.10   5.13.0-48-generic   containerd://1.5.11-k3s2
lima-node-3      Ready    <none>                      20m   v1.23.6+k3s1   192.168.105.40   192.168.105.40   Ubuntu 21.10   5.13.0-48-generic   containerd://1.5.11-k3s2

But would be very nice be able for setting the Slirp IP.

[authurlin168]

Can you have more description for the relationship among the guest IP (192.168.5.15/24), share IP 192.168.105.0/24 and host IP (192.168.2.0/24 )? I also using vmnet on my MacBook (Intel). I cannot ping guest IP from my MacBook but guest can reach out to the Internet.

guest info: $ ifconfig -a docker0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500 inet 172.17.0.1 netmask 255.255.0.0 broadcast 172.17.255.255 ether 02:42:ab:04:8d:9e txqueuelen 0 (Ethernet) RX packets 0 bytes 0 (0.0 B) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 0 bytes 0 (0.0 B) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500 inet 192.168.5.15 netmask 255.255.255.0 broadcast 192.168.5.255 inet6 fec0::5055:55ff:fe29:8ce5 prefixlen 64 scopeid 0x40 inet6 fe80::5055:55ff:fe29:8ce5 prefixlen 64 scopeid 0x20 ether 52:55:55:29:8c:e5 txqueuelen 1000 (Ethernet) RX packets 93238 bytes 136196626 (136.1 MB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 5613 bytes 476455 (476.4 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536 inet 127.0.0.1 netmask 255.0.0.0 inet6 ::1 prefixlen 128 scopeid 0x10 loop txqueuelen 1000 (Local Loopback) RX packets 286 bytes 27407 (27.4 KB) RX errors 0 dropped 0 overruns 0 frame 0 TX packets 286 bytes 27407 (27.4 KB) TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

$ netstat -rn Kernel IP routing table Destination Gateway Genmask Flags MSS Window irtt Iface 0.0.0.0 192.168.5.2 0.0.0.0 UG 0 0 0 eth0 172.17.0.0 0.0.0.0 255.255.0.0 U 0 0 0 docker0 192.168.5.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 192.168.5.2 0.0.0.0 255.255.255.255 UH 0 0 0 eth0 192.168.5.3 0.0.0.0 255.255.255.255 UH 0 0 0 eth0

$ fping www.google.com www.google.com is alive

How the guest (Lima instance) reach out www.google.com ? 192.168.5.2 -> 192.168.105.1 ?

[tommyminds]

Any update on what would be required to support this? We are in the unfortunate situation of our office CIDR precisely clashing with Lima's...

[mbentley]

I also have run into the situation where one of my existing networks is 192.168.5.0/24 so the ability to configure that by the user would be ideal. I am using a bridged network in my setup so I am not sure if I am missing anything in terms of an ability to completely disable the slirp network that is created and attached as eth0 but from what I can tell, there are dependencies on that local network to exist for lima to interact with the VM.

[balajiv113]

This PR https://github.com/lima-vm/lima/pull/1626 should address this by providing support for configurable usernet network

[balajiv113]

@AkihiroSuda This is now supported via user-v2. I think we can close this issue.

[AkihiroSuda]

Thanks!