* Assign pod priorityClassNames to critical cluster and node
components (higher is higher priority) to inform node out-of-resource
eviction order and scheduler preemption and scheduling order
* Priority Admission Controller has been enabled since Typhoon
v1.11.1
* Fix a regression caused by lowering the Kubelet TLS client
certificate to system:nodes group (#100) since dropping
cluster-admin dropped the Kubelet's ability to delete nodes.
* On clouds where workers can scale down (manual terraform apply,
AWS spot termination, Azure low priority deletion), worker shutdown
runs the delete-node.service to remove a node to prevent NotReady
nodes from accumulating
* Allow Kubelets to delete cluster nodes via system:nodes group. Kubelets
acting with system:node and kubelet-delete ClusterRoles is still an
improvement over acting as cluster-admin
* System components that require certificates signed by the cluster
CA can submit a CSR to the apiserver, have an administrator inspect
and approve it, and be issued a certificate
* Configure kube-controller-manager to sign Approved CSR's using the
cluster CA private key
* Admins are responsible for approving or denying CSRs, otherwise,
no certificate is issued. Read the Kubernetes docs carefully and
verify the entity making the request and the authorization level
* https://kubernetes.io/docs/tasks/tls/managing-tls-in-a-cluster
* Use a single admin kubeconfig for initial bootkube bootstrap
and for use by a human admin. Previously, an admin kubeconfig
without a named context was used for bootstrap and direct usage
with KUBECONFIG=path, while one with a named context was used
for `kubectl config use-context` style usage. Confusing.
* Provide the admin kubeconfig via `assets/auth/kubeconfig`,
`assets/auth/CLUSTER-config`, or output `kubeconfig-admin`
* terraform-render-bootkube module deprecated kube_dns_service_ip
output in favor of cluster_dns_service_ip
* Rename k8s_dns_service_ip to cluster_dns_service_ip for
consistency too
* Kubelets can use a lower-privilege TLS client certificate with
Org system:nodes and a binding to the system:node ClusterRole
* Admin kubeconfig's continue to belong to Org system:masters to
provide cluster-admin (available in assets/auth/kubeconfig or as
a Terraform output kubeconfig-admin)
* Remove bare-metal output variable kubeconfig
* Add ServiceAccounts and ClusterRoleBindings for kube-apiserver
and kube-scheduler
* Remove the ClusterRoleBinding for the kube-system default ServiceAccount
* Rename the CA certificate CommonName for consistency with upstream
* Add kube-router for pod networking and NetworkPolicy
as an experiment
* Experiments are not documented or supported in any way,
and may be removed without notice. They have known issues
and aren't enabled without special options.
* Remove bullet about isolating workloads on workers, its
now common practice and new users will assume it
* List advanced features available in each module
* Fix erroneous Kubernetes version listing for Google Cloud
Fedora Atomic
* Calico Felix has been reporting anonymous usage data about the
version and cluster size, which violates Typhoon's privacy policy
where analytics should be opt-in only
* Add a variable enable_reporting (default: false) to allow opting
in to reporting usage data to Calico (or future components)
* loop sends an initial query to detect infinite forwarding
loops in configured upstream DNS servers and fast exit with
an error (its a fatal misconfiguration on the network that
will otherwise cause resolvers to consume memory/CPU until
crashing, masking the problem)
* https://github.com/coredns/coredns/tree/master/plugin/loop
* loadbalance randomizes the ordering of A, AAAA, and MX records
in responses to provide round-robin load balancing (as usual,
clients may still cache responses though)
* https://github.com/coredns/coredns/tree/master/plugin/loadbalance
* Prefer InternalIP and ExternalIP over the node's hostname,
to match upstream behavior and kubeadm
* Previously, hostname-override was used to set node names
to internal IP's to work around some cloud providers not
resolving hostnames for instances (e.g. DO droplets)
* Updating the `terraform-provider-ct` plugin is known to produce
a `user_data` diff in all pre-existing clusters. Applying the
diff to pre-existing cluster destroys controller nodes
* Ignore changes to controller `user_data`. Once all managed
clusters use a release containing this change, it is possible
to update the `terraform-provider-ct` plugin (worker `user_data`
will still be modified)
* Changing the module `ref` for an existing cluster and
re-applying is still NOT supported (although this PR
would protect controllers from being destroyed)
* Improve the workers "round-robin" DNS FQDN that is created
with each cluster by adding AAAA records
* CNAME's resolving to the DigitalOcean `workers_dns` output
can be followed to find a droplet's IPv4 or IPv6 address
* The CNI portmap plugin doesn't support IPv6. Hosting IPv6
apps is possible, but requires editing the nginx-ingress
addon with `hostNetwork: true`
* Run at least two replicas of CoreDNS to better support
rolling updates (previously, kube-dns had a pod nanny)
* On multi-master clusters, set the CoreDNS replica count
to match the number of masters (e.g. a 3-master cluster
previously used replicas:1, now replicas:3)
* Add AntiAffinity preferred rule to favor distributing
CoreDNS pods across controller nodes nodes
* Continue to ensure scheduler and controller-manager run
at least two replicas to support performing kubectl edits
on single-master clusters (no change)
* For multi-master clusters, set scheduler / controller-manager
replica count to the number of masters (e.g. a 3-master cluster
previously used replicas:2, now replicas:3)
* Require a terraform-provider-digitalocean plugin version of
1.0 or higher within the same major version (e.g. allow 1.1 but
not 2.0)
* Change requirement from ~> 0.1.2 (which allowed up to but not
including 1.0 release)
* Add new bird and felix readiness checks
* Read MTU from ConfigMap veth_mtu
* Add RBAC read for serviceaccounts
* Remove invalid description from CRDs
* Adjust firewall rules, security groups, cloud load balancers,
and generated kubeconfig's
* Facilitates some future simplifications and cost reductions
* Bare-Metal users who exposed kube-apiserver on a WAN via their
router or load balancer will need to adjust its configuration.
This is uncommon, most apiserver are on LAN and/or behind VPN
so no routing infrastructure is configured with the port number
* Raise minimum Terraform version to v0.11.0
* Terraform v0.11.x has been supported since Typhoon v1.9.2
and Terraform v0.10.x was last released in Nov 2017. I'd like
to stop worrying about v0.10.x and remove migration docs as
a later followup
* Migration docs docs/topics/maintenance.md#terraform-v011x
* Use etcd v3.3 --listen-metrics-urls to expose only metrics
data via http://0.0.0.0:2381 on controllers
* Add Prometheus discovery for etcd peers on controller nodes
* Temporarily drop two noisy Prometheus alerts
* AWS and Google Cloud make use of auto-scaling groups
and managed instance groups, respectively. As such, the
kubeconfig is already held in cloud user-data
* Controller instances are provisioned with a kubeconfig
from user-data. Its redundant to use a Terraform remote
file copy step for the kubeconfig.
* Calico isn't viable on Digital Ocean because their firewalls
do not support IP-IP protocol. Its not viable to run a cluster
without firewalls just to use Calico.
* Remove the caveat note. Don't allow users to shoot themselves
in the foot
* Introduce the ability to support Container Linux Config
"snippets" for controllers and workers on cloud platforms.
This allows end-users to customize hosts by providing Container
Linux configs that are additively merged into the base configs
defined by Typhoon. Config snippets are validated, merged, and
show any errors during `terraform plan`
* Example uses include adding systemd units, network configs,
mounts, files, raid arrays, or other disk provisioning features
provided by Container Linux Configs (using Ignition low-level)
* Requires terraform-provider-ct v0.2.1 plugin
* Add a node-role.kubernetes.io/controller="true" node label
to controllers so Prometheus service discovery can filter to
services that only run on controllers (i.e. masters)
* Leave node-role.kubernetes.io/master="" untouched as its
a Kubernetes convention
* Set Kubelet search path for flexvolume plugins
to /var/lib/kubelet/volumeplugins
* Add support for flexvolume plugins on AWS, GCE, and DO
* See 9548572d98 which added flexvolume support for bare-metal
* Remove PersistentVolumeLabel admission controller flag
* Switch Deployments and DaemonSets to apps/v1
* Minor update to pod-checkpointer image version
* Add flannel service account and limited RBAC cluster role
* Change DaemonSets to tolerate NoSchedule and NoExecute taints
* Remove deprecated apiserver --etcd-quorum-read flag
* Update Calico from v3.0.1 to v3.0.2
* Add Calico GlobalNetworkSet CRD
* https://github.com/poseidon/terraform-render-bootkube/pull/44
* Change port range from keyword "all" to "1-65535", which is the
same but with digitalocean provider 0.1.3 doesn't produce a diff
* Rearrange egress firewall rules to order the Digtial Ocean API
and provider returns. In current testing, this fixes the last diff
that was present on `terraform plan`.
* Allow kube-dns to respond to DNS queries with a custom
suffix, instead of the default 'cluster.local'
* Useful when multiple clusters exist on the same local
network and wish to query services on one another
* When restarting masters, `etcd-member.service` may fail to lookup peers if
/etc/resolv.conf hasn't been populated yet. Require the wait-for-dns.service.
* Update hyperkube from v1.8.3 to v1.8.4
* Remove flock from bootstrap-apiserver and kube-apiserver
* Remove unused critical-pod annotations in manifests
* Use service accounts for kube-proxy and pod-checkpointer
* Update Calico from v2.6.1 to v2.6.3
* Update flannel from v0.9.0 to v0.9.1
* Remove Calico termination grace period to prevent calico
from getting stuck for extended periods
* https://github.com/poseidon/terraform-render-bootkube/pull/29
* Change controllers ASG to heterogeneous EC2 instances
* Create DNS records for each controller's private IP for etcd
* Change etcd to run on-host, across controllers (etcd-member.service)
* Reduce time to bootstrap a cluster
* Deprecate self-hosted-etcd on the AWS platform
* Change controllers from a managed group to individual instances
* Create discrete DNS records to each controller's private IP for etcd
* Change etcd to run on-host, across controllers (etcd-member.service)
* Reduce time to bootstrap a cluster
* Deprecate self-hosted-etcd on the Google Cloud platform
* Kubernetes v1.8.2 fixes a memory leak in the v1.8.1 apiserver
* Switch to using the `gcr.io/google_containers/hyperkube` for the
on-host kubelet and shutdown drains
* Update terraform-render-bootkube manifests generation
* Update flannel from v0.8.0 to v0.9.0
* Add `hairpinMode` to flannel CNI config
* Add `--no-negcache` to kube-dns dnsmasq
* Run etcd peers with TLS across controller nodes
* Deprecate self-hosted-etcd on the Digital Ocean platform
* Distribute etcd TLS certificates as part of initial provisioning
* Check the status of etcd by running `systemctl status etcd-member`
* Mounting NFS exports as volumes from some NFS servers fails because
the kubelet isn't starting rpc-statd as expected. Describing pods
that are stuck creating shows rpc.statd is required for remote locking
* Starting rpc-statd.service resolves the issue and all NFS mounts
seem to be working.
* Recommended approach https://github.com/coreos/bugs/issues/2074
* Mount host /opt/cni/bin in Kubelet to use host's CNI plugins
* Switch /var/run/kubelet-pod.uuid to /var/cache/kubelet-pod.uuid
to persist between reboots and cleanup old Kubelet pods
* Organize Kubelet flags in alphabetical order
* Calico on GCE with IP-in-IP encapsulation and MTU 1440
* Calico on DO with IP-in-IP encapsulation and MTU 1440
* Digital Ocean firewalls don't support IPIP protocol yet
* Without a reference a Digital Ocean tag object, terraform may
try to create a firewall rule before a tag actually exists. By
referencing the actual tag objects, the dependency order is
implied
* Remove k8s_domain_name input variable, the controller DNS
record will be "${var.cluster_name}.${dns_zone}"
* Rename dns_base_zone to dns_zone
* Rename dns_base_zone_name to dns_zone_name
* Kubelets should register nodes via their private IPv4 address,
as provided by the metadata service from Digital Ocean
* By default, Kubelet exec's hostname to determine the name it should
use when registering with the apiserver. On Digital Ocean, the hostname
is not routeable by other instances. Digital Ocean does not run an
internal DNS service.
* Fixes issue where the apiserver can't reach the worker nodes. This
prevented kubectl logs and exec commands from working
