cloud-init bug filed @ https://github.com/canonical/cloud- init/issues/4451
** Bug watch added: github.com/canonical/cloud-init/issues #4451 https://github.com/canonical/cloud-init/issues/4451 -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/2036968 Title: Mantic minimized/minimal cloud images do not receive IP address during provisioning Status in cloud-images: New Status in linux package in Ubuntu: Incomplete Bug description: Following a recent change from linux-kvm kernel to linux-generic kernel in the mantic minimized images, there is a reproducable bug where a guest VM does not have an IP address assigned as part of cloud-init provisioning. This is easiest to reproduce when emulating arm64 on amd64 host. The bug is a race condition, so there could exist fast enough virtualisation on fast enough hardware where this bug is not present but in all my testing I have been able to reproduce. The latest mantic minimized images from http://cloud- images.ubuntu.com/minimal/daily/mantic/ have force initrdless boot and no initrd to fallback to. This but is not present in the non minimized/base images @ http://cloud-images.ubuntu.com/mantic/ as these boot with initrd with the required drivers present for virtio-net. Reproducer ``` wget -O "launch-qcow2-image-qemu-arm64.sh" https://people.canonical.com/~philroche/20230921-cloud-images-mantic-fail-to-provision/launch-qcow2-image-qemu-arm64.sh chmod +x ./launch-qcow2-image-qemu-arm64.sh wget https://people.canonical.com/~philroche/20230921-cloud-images-mantic-fail-to-provision/livecd.ubuntu-cpc.img ./launch-qcow2-image-qemu-arm64.sh --password passw0rd --image ./livecd.ubuntu-cpc.img ``` You will then be able to log in with user `ubuntu` and password `passw0rd`. You can run `ip a` and see that there is a network interface present (separate to `lo`) but no IP address has been assigned. ``` ubuntu@cloudimg:~$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enp0s1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000 link/ether 52:54:00:12:34:56 brd ff:ff:ff:ff:ff:ff ``` This is because when cloud-init is trying to configure network interfaces it doesn't find any so it doesn't configure any. But by the time boot is complete the network interface is present but cloud-init provisioning has already completed. You can verify this by running `sudo cloud-init clean && sudo cloud- init init` You can then see a successfully configured network interface ``` ubuntu@cloudimg:~$ ip a 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 2: enp0s1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000 link/ether 52:54:00:12:34:56 brd ff:ff:ff:ff:ff:ff inet 10.0.2.15/24 metric 100 brd 10.0.2.255 scope global dynamic enp0s1 valid_lft 86391sec preferred_lft 86391sec inet6 fec0::5054:ff:fe12:3456/64 scope site dynamic mngtmpaddr noprefixroute valid_lft 86393sec preferred_lft 14393sec inet6 fe80::5054:ff:fe12:3456/64 scope link valid_lft forever preferred_lft forever ``` The bug is also reproducible with amd64 guest on adm64 host on older/slower hardware. The suggested fixes while debugging this issue are: * to include `virtio-net` as a built-in in the mantic generic kernel * understand what needs to change in cloud-init so that it can react to late additions of network interfaces I will file a separate bug against cloud-init to address the race condition on emulated guest/older hardware. To manage notifications about this bug go to: https://bugs.launchpad.net/cloud-images/+bug/2036968/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
