* Run a kube-apiserver, kube-scheduler, and kube-controller-manager
static pod on each controller node. Previously, kube-apiserver was
self-hosted as a DaemonSet across controllers and kube-scheduler
and kube-controller-manager were a Deployment (with 2 or
controller_count many replicas).
* Remove bootkube bootstrap and pivot to self-hosted
* Remove pod-checkpointer manifests (no longer needed)
* Change default controller_type to Standard_B2s. A B2s is cheaper
by $17/month and provides 2 vCPU, 4GB RAM (vs 1 vCPU, 3.5GB RAM)
* Change default worker_type to Standard_DS1_v2. F1 was the previous
generation. The DS1_v2 is newer, similar cost, more memory, and still
supports Low Priority mode, if desired
* Use unique dashboard ID so that multiple replicas of Grafana
serve dashboards with uniform paths
* Fix issue where refreshing a dashboard served by one replica
could show a 404 unless the request went to the same replica
* terraform-provider-aws v2.23.0 allows AWS root block devices
to enable encryption by default.
* Require updating terraform-provider-aws to v2.23.0 or higher
* Enable root EBS device encryption by default for controller
instances and worker instances in auto-scaling groups
For comparison:
* Google Cloud persistent disks have been encrypted by
default for years
* Azure managed disk encryption is not ready yet (#486)
* Add a CoreDNS dashboard originally based on an upstream dashboard,
but now customized according to preferences
* Add an Nginx Ingress Controller based on an upstream dashboard,
but customized according to preferences
* Describe kube-apiserver load balancing on each platform
* Describe HTTP/S Ingress load balancing on each platform
* Describe TCP/UDP load balancing apps on each platform
(some clouds don't support UDP)
* Describe firewall customization (e.g. for TCP/UDP apps)
* Update IPv6 status for each platform
* For Fedora CoreOS, only HTTPS downloads are available.
Any iPXE firmware must be compiled to support TLS fetching.
* For Container Linux, using public kernel/initramfs images
defaults to using HTTPS, but can be set to HTTP for iPXE
firmware that hasn't been custom compiled to support TLS
* Add all Azure controllers to the apiserver load balancer
backend address pool
* Previously, kube-apiserver availability relied on the 0th
controller being up. Multi-controller was just providing etcd
data redundancy
* Intended as part of #504 improvement
* Single controller clusters only require one controller
instance group (previously created zone-many)
* Multi-controller clusters must "wrap" controllers over
zonal heterogeneous instance groups. For example, 5
controllers over 3 zones (no change)
* Kubelets can hit the ContainerManager Delegation issue and fail
to start (noted in 72c94f1c6). Its unclear why this occurs only
to some Kubelets (possibly an ordering concern)
* QoS cgroups remain a goal
* When a controller node is affected, bootstrapping fails, which
makes other development harder. Temporarily disable QoS on
controllers only. This should safeguard bring-up and hopefully
still allow the issue to occur on some workers for debugging
* Use the xz compressed images published by Fedora testing,
instead of gzippped tarballs. This is possible because the
initramfs now supports xz and coreos-installer 0.8 was added
* Separate bios and uefi raw images are no longer needed
* Use the newly minted "Fedora CoreOS Preview" AMI
* Remove iscsi, kubelet.path activation, and kubeconfig
distribution
* As usual, bare-metal efforts make cloud provider ports
much easier
* First semi-working cluster using 30.307-metal-bios
* Enable CPU, Memory, and BlockIO accounting
* Mount /var/lib/kubelet with `rshare` so mounted tmpfs Secrets
(e.g. serviceaccount's) are visible within appropriate containers
* SELinux relabel /etc/kubernetes so install-cni init containers
can write the CNI config to the host /etc/kubernetes/net.d
* SELinux relabel /var/lib/kubelet so ConfigMaps can be read
by containers
* SELinux relabel /opt/cni/bin so install-cni containers can
write CNI binaries to the host
* Set net.ipv4_conf.all.rp_filter to 1 (not 2, loose mode) to
satisfy Calico requirement
* Enable the QoS cgroup hierarchy for pod workloads (kubepods,
burstable, besteffort). Mount /sys/fs/cgroup and
/sys/fs/cgroup/systemd into the Kubelet. Its still rather racy
whether Kubelet will fail on ContainerManager Delegation
Dalton Hubble
Bob Henkel