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.
A while back options to permit secure kube-apiserver to kubelet api was https://github.com/kubernetes/kops/pull/2831 using the server.cert and server.key as testing grouns. This PR formalizes the options and generates a client certificate on their behalf (note, the server{.cert,key} can no longer be used post 1.7 as the certificate usage is checked i.e. it's not using a client cert). The users now only need to add anonymousAuth: false to enable secure api to kubelet. I'd like to make this default to all new builds i'm not sure where to place it.
- updated the security.md to reflect the changes
- issue a new client kubelet-api certificate used to secure authorize comms between api and kubelet
- fixed any formatting issues i came across on the journey
The current implementation does not put any transport security on the etcd cluster. The PR provides and optional flag to enable TLS the etcd cluster
- cleaned up and fixed any formatting issues on the journey
- added two new certificates (server/client) for etcd peers and a client certificate for kubeapi and others perhaps (perhaps calico?)
- disabled the protokube service for nodes completely is not required; note this was first raised in https://github.com/kubernetes/kops/pull/3091, but figured it would be easier to place in here given the relation
- updated protokube codebase to reflect the changes, removing the master option as its no longer required
- added additional integretion tests for the protokube manifests;
- note, still need to add documentation, but opening the PR to get feedback
- one outstanding issue is the migration from http -> https for preexisting clusters, i'm gonna hit the coreos board to ask for the best options
Stop using the networking-plugin-dir flag, and replace with the
cni-bin-dir and cni-conf-dir flags, set appropriately.
Thanks for spotting @prachetasp
Issue #2267
We move everything to the models. We feature-flag it, because we
probably want to change the names etc, and we aren't going to be able to
offer smooth upgrades until that is done.
We build a statically linked version and distribute it with kops.
Note that our version of socat does not include libssl, but kubernetes
does not use it anyway.
Rohith
Simone Sciarrati
Justin Santa Barbara
Blake
chrislovecnm
Michael Taufen