Client Authentication (v1)

Resource Types

ExecCredential

ExecCredential is used by exec-based plugins to communicate credentials to HTTP transports.

FieldDescription
apiVersion
string		client.authentication.k8s.io/v1
kind
string		ExecCredential
spec [Required]
ExecCredentialSpec 		Spec holds information passed to the plugin by the transport.
status
ExecCredentialStatus 		Status is filled in by the plugin and holds the credentials that the transport should use to contact the API.

Cluster

Appears in:

Cluster contains information to allow an exec plugin to communicate with the kubernetes cluster being authenticated to.

To ensure that this struct contains everything someone would need to communicate with a kubernetes cluster (just like they would via a kubeconfig), the fields should shadow "k8s.io/client-go/tools/clientcmd/api/v1".Cluster, with the exception of CertificateAuthority, since CA data will always be passed to the plugin as bytes.

FieldDescription
server [Required]
string 		Server is the address of the kubernetes cluster (https://hostname:port).
tls-server-name
string 		TLSServerName is passed to the server for SNI and is used in the client to check server certificates against. If ServerName is empty, the hostname used to contact the server is used.
insecure-skip-tls-verify
bool 		InsecureSkipTLSVerify skips the validity check for the server's certificate. This will make your HTTPS connections insecure.
certificate-authority-data
[]byte 		CAData contains PEM-encoded certificate authority certificates. If empty, system roots should be used.
proxy-url
string 		ProxyURL is the URL to the proxy to be used for all requests to this cluster.
config
k8s.io/apimachinery/pkg/runtime.RawExtension 		Config holds additional config data that is specific to the exec plugin with regards to the cluster being authenticated to.

This data is sourced from the clientcmd Cluster object's extensions[client.authentication.k8s.io/exec] field:

clusters:

  • name: my-cluster cluster: ... extensions:
    • name: client.authentication.k8s.io/exec # reserved extension name for per cluster exec config extension: audience: 06e3fbd18de8 # arbitrary config

In some environments, the user config may be exactly the same across many clusters (i.e. call this exec plugin) minus some details that are specific to each cluster such as the audience. This field allows the per cluster config to be directly specified with the cluster info. Using this field to store secret data is not recommended as one of the prime benefits of exec plugins is that no secrets need to be stored directly in the kubeconfig.

ExecCredentialSpec

Appears in:

ExecCredentialSpec holds request and runtime specific information provided by the transport.

FieldDescription
cluster
Cluster 		Cluster contains information to allow an exec plugin to communicate with the kubernetes cluster being authenticated to. Note that Cluster is non-nil only when provideClusterInfo is set to true in the exec provider config (i.e., ExecConfig.ProvideClusterInfo).
interactive [Required]
bool 		Interactive declares whether stdin has been passed to this exec plugin.

ExecCredentialStatus

Appears in:

ExecCredentialStatus holds credentials for the transport to use.

Token and ClientKeyData are sensitive fields. This data should only be transmitted in-memory between client and exec plugin process. Exec plugin itself should at least be protected via file permissions.

FieldDescription
expirationTimestamp
meta/v1.Time 		ExpirationTimestamp indicates a time when the provided credentials expire.
token [Required]
string 		Token is a bearer token used by the client for request authentication.
clientCertificateData [Required]
string 		PEM-encoded client TLS certificates (including intermediates, if any).
clientKeyData [Required]
string 		PEM-encoded private key for the above certificate.
Last modified December 09, 2021 at 10:24 AM PST : Improve configuration API for 1.23 (bce7fb57e)