A good practice for production kubernetes clusters is to separate etcd and controlplane services from the worker nodes.
In our case it will also allow to have homogenous worker nodes and put the kubernetes overhead outside the cassandra servers by themselves.
Spec:
3 vms with 4 vcpus and 8Go each, default disks
| Status | Assigned | Task | ||
|---|---|---|---|---|
| Migrated | gitlab-migration | T4373 [cassandra] Test the new hardware | ||
| Migrated | gitlab-migration | T4379 [cassandra] create etcd / controlplane servers | ||
| Migrated | gitlab-migration | T4375 [cassandra] One cassandra per data disk | ||
| Migrated | gitlab-migration | T4374 [cassandra] Test basic topology |
The management nodes were correctly created but it seems rancher is having some issuer to register them in the cluster.
I couldn't figure yet why this is faliing.
I found nothing weird in the logs (even with the TRACE level activated following https://rancher.com/docs/rancher/v2.5/en/troubleshooting/logging/)
Finally, the cluster is up.
I'm not sure what unstuck the node registration, but I suspect a node with all the roles is needed to bootstrap the cluster.
I tried this initially, it didn't worked, but I'm not sure in which status the cluster was.
The cassandra nodes were initialized and configured with these commands :
mkdir -p /etc/facter/facts.d cat >/etc/facter/facts.d/deployment.txt <<EOF deployment=production EOF cat >/etc/facter/facts.d/subnet.txt <<EOF subnet=sesi_rocquencourt EOF echo "192.168.100.29 pergamon.internal.softwareheritage.org" >> /etc/hosts echo "nameserver 192.168.100.29" >/etc/resolv.conf apt update; apt install -y facter puppet gnupg apt -y dist-upgrade reboot apt autoremove puppet agent --test --fqdn cassandra0[0-6].internal.softwareheritage.org --server pergamon.internal.softwareheritage.org reboot lvcreate -L100G --name docker $(hostname)-vg systemctl stop docker docker.socket rm -rf /var/lib/docker zpool create docker /dev/$(hostname)-vg/docker zfs set compress=zstd atime=off relatime=on docker zfs create -o mountpoint=/var/lib/docker docker/lib systemctl restart docker
+ the docker command given by rancher to initialize a worker