Migrate Fedora CoreOS bare-metal to static pod control plane

* 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)
This commit is contained in:
Dalton Hubble
2019-09-03 22:00:34 -07:00
parent b60a2ecdf7
commit 74780fb09f
8 changed files with 65 additions and 52 deletions

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@ -11,7 +11,7 @@ Typhoon distributes upstream Kubernetes, architectural conventions, and cluster
## Features <a href="https://www.cncf.io/certification/software-conformance/"><img align="right" src="https://storage.googleapis.com/poseidon/certified-kubernetes.png"></a>
* Kubernetes v1.15.3 (upstream, via [kubernetes-incubator/bootkube](https://github.com/kubernetes-incubator/bootkube))
* Kubernetes v1.15.3 (upstream)
* Single or multi-master, [Calico](https://www.projectcalico.org/) or [flannel](https://github.com/coreos/flannel) networking
* On-cluster etcd with TLS, [RBAC](https://kubernetes.io/docs/admin/authorization/rbac/)-enabled, [network policy](https://kubernetes.io/docs/concepts/services-networking/network-policies/)
* Advanced features like [snippets](https://typhoon.psdn.io/advanced/customization/#container-linux) customization

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@ -1,6 +1,6 @@
# Self-hosted Kubernetes assets (kubeconfig, manifests)
module "bootkube" {
source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=98cc19f80f2c4c3ddc63fc7aea6320e74bec561a"
source = "git::https://github.com/poseidon/terraform-render-bootkube.git?ref=6e59af71138bc5f784453873074de16e7ee150eb"
cluster_name = var.cluster_name
api_servers = [var.k8s_domain_name]

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@ -118,33 +118,48 @@ systemd:
PathExists=/etc/kubernetes/kubeconfig
[Install]
WantedBy=multi-user.target
- name: bootkube.service
- name: bootstrap.service
contents: |
[Unit]
Description=Bootstrap a Kubernetes control plane
ConditionPathExists=!/opt/bootkube/init_bootkube.done
Description=Kubernetes control plane
ConditionPathExists=!/opt/bootstrap/bootstrap.done
[Service]
Type=oneshot
RemainAfterExit=true
WorkingDirectory=/opt/bootkube
ExecStart=/usr/bin/bash -c 'set -x && \
[ -n "$(ls /opt/bootkube/assets/manifests-*/* 2>/dev/null)" ] && mv /opt/bootkube/assets/manifests-*/* /opt/bootkube/assets/manifests && rm -rf /opt/bootkube/assets/manifests-* && exec podman run --name bootkube --privileged \
WorkingDirectory=/opt/bootstrap
ExecStartPre=-/usr/bin/bash -c 'set -x && [ -n "$(ls /opt/bootstrap/assets/manifests-*/* 2>/dev/null)" ] && mv /opt/bootstrap/assets/manifests-*/* /opt/bootstrap/assets/manifests && rm -rf /opt/bootstrap/assets/manifests-*'
ExecStart=/usr/bin/podman run --name bootstrap \
--network host \
--volume /opt/bootkube/assets:/assets \
--volume /etc/kubernetes:/etc/kubernetes \
quay.io/coreos/bootkube:v0.14.0 \
/bootkube start --asset-dir=/assets'
ExecStartPost=/bin/touch /opt/bootkube/init_bootkube.done
--volume /opt/bootstrap/assets:/assets:ro,Z \
--volume /opt/bootstrap/apply:/apply:ro,Z \
k8s.gcr.io/hyperkube:v1.15.3 \
/apply
ExecStartPost=/bin/touch /opt/bootstrap/bootstrap.done
ExecStartPost=-/usr/bin/podman stop bootstrap
storage:
directories:
- path: /etc/kubernetes
- path: /opt/bootkube
- path: /opt/bootstrap
files:
- path: /etc/hostname
mode: 0644
contents:
inline:
${domain_name}
- path: /opt/bootstrap/apply
mode: 0544
contents:
inline: |
#!/bin/bash -e
export KUBECONFIG=/assets/auth/kubeconfig
until kubectl version; do
echo "Waiting for static pod control plane"
sleep 5
done
until kubectl apply -f /assets/manifests -R; do
echo "Retry applying manifests"
sleep 5
done
- path: /etc/sysctl.d/reverse-path-filter.conf
contents:
inline: |

View File

@ -89,7 +89,6 @@ systemd:
storage:
directories:
- path: /etc/kubernetes
- path: /opt/bootkube
files:
- path: /etc/hostname
mode: 0644

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@ -1,4 +1,4 @@
# Secure copy etcd TLS assets and kubeconfig to controllers. Activates kubelet.service
# Secure copy assets to controllers. Activates kubelet.service
resource "null_resource" "copy-controller-secrets" {
count = length(var.controller_names)
@ -7,6 +7,7 @@ resource "null_resource" "copy-controller-secrets" {
depends_on = [
matchbox_group.controller,
matchbox_group.worker,
module.bootkube,
]
connection {
@ -55,6 +56,11 @@ resource "null_resource" "copy-controller-secrets" {
content = module.bootkube.etcd_peer_key
destination = "$HOME/etcd-peer.key"
}
provisioner "file" {
source = var.asset_dir
destination = "$HOME/assets"
}
provisioner "remote-exec" {
inline = [
@ -67,6 +73,11 @@ resource "null_resource" "copy-controller-secrets" {
"sudo mv etcd-peer.crt /etc/ssl/etcd/etcd/peer.crt",
"sudo mv etcd-peer.key /etc/ssl/etcd/etcd/peer.key",
"sudo mv $HOME/kubeconfig /etc/kubernetes/kubeconfig",
"sudo mv $HOME/assets /opt/bootstrap/assets",
"sudo mkdir -p /etc/kubernetes/bootstrap-secrets",
"sudo cp -r /opt/bootstrap/assets/tls/* /etc/kubernetes/bootstrap-secrets/",
"sudo cp /opt/bootstrap/assets/auth/kubeconfig /etc/kubernetes/bootstrap-secrets/",
"sudo cp -r /opt/bootstrap/assets/static-manifests/* /etc/kubernetes/manifests/"
]
}
}
@ -101,9 +112,8 @@ resource "null_resource" "copy-worker-secrets" {
}
}
# Secure copy bootkube assets to ONE controller and start bootkube to perform
# one-time self-hosted cluster bootstrapping.
resource "null_resource" "bootkube-start" {
# Connect to a controller to perform one-time cluster bootstrap.
resource "null_resource" "bootstrap" {
# Without depends_on, this remote-exec may start before the kubeconfig copy.
# Terraform only does one task at a time, so it would try to bootstrap
# while no Kubelets are running.
@ -119,15 +129,9 @@ resource "null_resource" "bootkube-start" {
timeout = "15m"
}
provisioner "file" {
source = var.asset_dir
destination = "$HOME/assets"
}
provisioner "remote-exec" {
inline = [
"sudo mv $HOME/assets /opt/bootkube",
"sudo systemctl start bootkube",
"sudo systemctl start bootstrap",
]
}
}