vmbuilder team mailing list archive

[Chad Smith <chad.smith@xxxxxxxxxxxxx>]

The proposal to merge lp:~chad.smith/vmbuilder/jenkins_kvm_azure_netplan_hotplug into lp:~ubuntu-on-ec2/vmbuilder/jenkins_kvm has been updated.

Description changed to:

Azure images deliver a script /usr/local/sbin/ephemeral_eth.sh which is called from udev add rules on nic hotplug events for nics named eth[1-9]*. This script was created when netplan wasn't a 'thing' and, as such, only cared about /etc/network/interfaces.

In Artful and later, cloud-init writes a fallback interface config in /etc/netplan/50-cloud-init.yaml configuration dhcp on eth0 as a primary/mandatory NIC (optional: false). So boot will wait on that device to come up.

This changeset adds a test whether netplan command exists in ephemeral_eth.sh:
  - If netplan is present, a separate /etc/netplan/90-hotplug-<nicname>.yaml will be generated for each network device eth[1-9]n* that is attached after cloud-init's initial network configuration.
  - After the netplan yaml is created, call 'netplan apply' to bring up that device with dchp. The netplan config will specify that these nics are "optional: true" so that subsequent boots will not wait on them to come up in case they are subsequently detached.

Attaching nics in Azure is done through their UI or API. The attaching/detaching operation in Azure requires an instance to be stopped before attach/detach and started after the operation.

  Potental gap:
     There is no attempt to clean up old netplan yaml files, or to designate a new primary/mandatory nic because this original hotplug script didn't deal with udev rules for hotplug removal of nics (via Azure network interface detachment).
     This could present a minor issue if eth1 is attached (and optional by design) and eth0 gets detached. In that case, systemd may still wait for eth0 to come up because of the mandatory eth0 definition in /etc/netplan/50-cloud-init.yaml.

For more details, see:
https://code.launchpad.net/~chad.smith/vmbuilder/jenkins_kvm_azure_netplan_hotplug/+merge/347212
-- 
Your team VMBuilder is requested to review the proposed merge of lp:~chad.smith/vmbuilder/jenkins_kvm_azure_netplan_hotplug into lp:~ubuntu-on-ec2/vmbuilder/jenkins_kvm.