Daniel's Notes

In what continues to be very off-brand content for me (I'm really a kernel developer, I promise!), here are some random notes on some k8s stuff that will hopefully help someone. I'll keep this post as a running log of interesting stuff as I study for the CKA exam. Deploying k8s with the Canonical Distribution of Kubernetes (CDK) Does your deployment hang forever with kubernetes-master "Waiting for kube-system pods to start"? I was using a local deployment with LXD, and I needed to do the following 3 things: Disable swap on the host. In my case, I used juju ssh to connect to a kubernetes-master unit, then kubectl get nodes|less -S . This informed me that the nodes weren't starting the container runtime. Using juju ssh to connect to a node and running sudo kubectl , I found out that the container runtime was refusing to start because the host had swap memory enabled! After disabling that with sudo swapoff -a on the host, I was able to make progress an...

What do netplan apply, netplan generate, and netplan try do? The netplan man page just talks about the YAML configuration file format and don't describe the commands. So consider this a set of draft manpages - my hope is that it will fill in the gaps. I will try to get them merged to the main repository. Background To understand the netplan commands, it's helpful to know the very basics of the netplan design. Using netplan is a 2 step process: Netplan takes YAML files - usually from /etc/netplan/*.yaml - and converts them into configuration that is read by a backend .  This backend interacts with the kernel to actually configure the devices. Netplan currently supports systemd-networkd and NetworkManager as backends. So it will convert your configuration into the configuration that they read, and then they will actually apply it to the machine. Netplan doesn't do any configuration itself. With this in mind, we can understand the components netplan generate N...