- Note sure how I missed this, but the options builder is run before the validation which will always cause and issue (we need to add a warning instead)
- for now, given if the user is already using the AdmissionControllers it's fixed later in the chain we will only check the Disabled plugins for now
a) The current implementation use's a static kubelet which doesn't not conform to the Node authorization mode (i.e. system:nodes:<nodename>)
b) As present the kubeconfig is static and reused across all the masters and nodes
The PR firstly introduces the ability for users to use bootstrap tokens and secondly when enabled ensure the kubelets for the masters as have unique usernames. Note, this PR does not attempt to address the distribution of the bootstrap tokens themselves, that's for cluster admins. One solution for this would be a daemonset on the masters running on hostNetwork and reuse dns-controller to annotated the pods and give as the DNS
Notes:
- the master node do not use bootstrap tokens, instead given they have access to the ca anyhow, we generate certificates for each.
- when bootstrap token is not enabled the behaviour will stay the same; i.e. a kubelet configuration brought down from the store.
- when bootstrap tokens are enabled, the Nodes sit in a timeout loop waiting for the configuration to appear (by third party).
- given the nodeup docker and manifests builders are executed before the kubelet builder, the assumption here is a unit file kicks of a custom container to bootstrap the rest.
- the current firewalls on between the master and nodes are fairly open so no need to open ports between the two
- much of the work was ported from @justinsb PR [here](https://github.com/kubernetes/kops/pull/4134/)
- we add a very presumptuous server and client certificates for use with an authorizer (node-bootstrap-internal.dns_zone)
I do have an additional PR which performs the entire thing. The process being a node_authorizer which runs on the master nodes via a daemonset, the service implements a series of authorizers (i.e. alwaysallow, aws, gce etc). For aws, the process is similar to how vault authorizes nodes [here](https://www.vaultproject.io/docs/auth/aws.html). Nodeup no then calls out to the node_authorizer on bootstrap and provisions the kubelet.
The current implementation doesnt appear to validate the fileAssets on the instanceGroups, just the cluster spec.
- validating the fileAssets per instancegroup
Since v1.10.0 the --admission-control is being deprecated in favour or --enable-admission-plugin, we should enforce the behaviour in the validation code
I did a fix for this a [moment ago](https://github.com/kubernetes/kops/pull/5248), but yes, enforcement is a better option than trying to support both
Maciej Kwiek
Rohith
k8s-ci-robot
Peter Rifel
chrislovecnm
Andrew Sy Kim
Tomas Virgl
Ripta Pasay
Justin Santa Barbara
Ian Hoegen
Rodrigo Menezes
AdamDang
Ali Rizwan
Stephen McQuay (smcquay)
Aurel Canciu