Allow the group claim to be a single string instead of an array of
strings. This means the following claim
{
"role": "admin"
}
Will be mapped to the groups
["admin"]
Automatic merge from submit-queue
Refactor cert utils into one pkg, add funcs from bootkube for kubeadm to use
**What this PR does / why we need it**:
We have ended-up with rather incomplete and fragmented collection of utils for handling certificates. It may be worse to consider using `cfssl` for doing all of these things, but for now there is some functionality that we need in `kubeadm` that we can borrow from bootkube. It makes sense to move the utils from bookube into core, as discussed in #31221.
**Special notes for your reviewer**: I've taken the opportunity to review names of existing funcs and tried to make some improvements in that area (with help from @peterbourgon).
**Release note**:
```release-note
NONE
```
* Allow options.InsecurePort to be set to 0 to switch off insecure access
* In NewSelfClient, Set the TLSClientConfig to the cert and key files
if InsecurePort is switched off
* Mint a bearer token that allows the client(s) created in NewSelfClient
to talk to the api server
* Add a new authenticator that checks for this specific bearer token
Fixes#13598
Automatic merge from submit-queue
plugin/pkg: add ericchiang to owners for OpenID Connect plugins
On the CoreOS side I'm taking over these components.
@erictune has suggested `pkg/registry/{cluster}role{binding}s/OWNERS` as well but I'd feel more comfortable as a reviewer for those specific parts of RBAC for a couple more cycles since @liggitt and @deads2k have had way more experience in the registry code.
Beyond that the only existing OWNERS files for auth are `pkg/auth/OWNERS` and `plugin/pkg/auth/OWNERS` both of which include @liggitt and @erictune. There's also nothing in the `plugin/pkg/client` path. I'm a little unclear on the implications for future PRs that are assigned to me (e.g. webhook or RBAC reviews).
cc @kubernetes/sig-auth
Automatic merge from submit-queue
oidc authentication plugin: don't trim issuer URLs with trailing slashes
The issuer URL passed to the plugin must identically match the issuer
URL returned by OpenID Connect discovery. However, the plugin currently
trims all trailing slashes from issuer URLs, causing a mismatch. Since
the go-oidc client already handles this case correctly, don't trim the
path.
Closes#29749
cc @hanikesn @kubernetes/sig-auth
The issuer URL passed to the plugin must identically match the issuer
URL returned by OpenID Connect discovery. However, the plugin currently
trims all trailing slashes from issuer URLs, causing a mismatch. Since
the go-oidc client already handles this case correctly, don't trim the
path.
Automatic merge from submit-queue
oidc auth plugin: don't hard fail if provider is unavailable
When using OpenID Connect authentication, don't cause the API
server to fail if the provider is unavailable. This allows
installations to run OpenID Connect providers after starting the
API server, a common case when the provider is running on the
cluster itself.
Errors are now deferred to the authenticate method.
cc @sym3tri @erictune @aaronlevy @kubernetes/sig-auth
When using OpenID Connect authentication, don't cause the API
server to fail if the provider is unavailable. This allows
installations to run OpenID Connect providers after starting the
API server, a common case when the provider is running on the
cluster itself.
Errors are now deferred to the authenticate method.
Automatic merge from submit-queue
Cache Webhook Authentication responses
Add a simple LRU cache w/ 2 minute TTL to the webhook authenticator.
Kubectl is a little spammy, w/ >= 4 API requests per command. This also prevents a single unauthenticated user from being able to DOS the remote authenticator.
The provider config has changed a little bit in go-oidc. It is more
complete and now throws errors when unmarshaling provider configs
that are missing required fields (as defined by the OpenID Connect
Discovery spec).
Update the oidc plugin to use the new type.
Also add related new flags to apiserver:
"--oidc-issuer-url", "--oidc-client-id", "--oidc-ca-file", "--oidc-username-claim",
to enable OpenID Connect authentication.
