## CA Flow

istio-agent checks the presence of a socket file on the defined **socket path** `/var/run/secrets/workload-spiffe-uds/socket`.

* If a socket is found, istio-agent will not start its own SDS Server and Envoy will be configured to use that socket as its source of cryptographic material.

  lua: warning
  main: warning
  misc: warning
  mongo: warning
  quic: warning
  pool: warning
  rbac: warning
  redis: warning
  router: warning
  runtime: warning
  stats: warning
  secret: warning
  tap: warning
  testing: warning
  thrift: warning
  tracing: warning
  upstream: warning
  udp: warning

option go_package = "k8s.io/api/authentication/v1";

// BoundObjectReference is a reference to an object that a token is bound to.
message BoundObjectReference {
  // Kind of the referent. Valid kinds are 'Pod' and 'Secret'.
  // +optional
  optional string kind = 1;

  // API version of the referent.
  // +optional
  optional string apiVersion = 2;

  // Name of the referent.
  // +optional
  optional string name = 3;

  // Since non-resource URLs are not namespaced, this field is only applicable for ClusterRoles referenced from a ClusterRoleBinding.
  // Rules can either apply to API resources (such as "pods" or "secrets") or non-resource URL paths (such as "/api"),  but not both.
  // +optional
  repeated string nonResourceURLs = 6;
}

  // Since non-resource URLs are not namespaced, this field is only applicable for ClusterRoles referenced from a ClusterRoleBinding.
  // Rules can either apply to API resources (such as "pods" or "secrets") or non-resource URL paths (such as "/api"),  but not both.
  // +optional
  repeated string nonResourceURLs = 5;
}

This is rooted in the Multicluster Secret controller, which reads `kubeconfig` files (stored as `Secrets`), and creating Kubernetes clients for each. The controller allows registering handlers which can process Add/Update/Delete of clusters.

This has two implementations:
* The Credentials controller is responsible for reading TLS certificates, stored as Secrets.

RESOURCE NAME      TYPE           STATUS     VALID CERT     SERIAL NUMBER                        NOT AFTER                NOT BEFORE
secret/default     Cert Chain     ACTIVE     false          6fbee254c22900615cb1f74e3d2f1713     2023-05-16T01:32:52Z     2023-05-15T01:30:52Z
secret/ROOTCA      CA             ACTIVE     true           193a543fe2b0d9cd4847675394dfc54      2033-05-02T03:41:33Z     2023-05-05T03:41:33Z

Changes:
- separate namespace allows:
-- easier reconfig of just the gateway
-- TLS secrets and domain name management is isolated, for better security
-- simplified configuration
-- multiple versions of the ingress can be used, to minize upgrade risks

- the new chart uses the default namespace service account, and doesn't require
additional RBAC permissions.

- simplified label structure. Label change is not supported on upgrade.

Changes:
- separate namespace allows:
-- easier reconfig of just the gateway
-- TLS secrets and domain name management is isolated, for better security
-- simplified configuration
-- multiple versions of the ingress can be used, to minimize upgrade risks

- the new chart uses the default namespace service account, and doesn't require
additional RBAC permissions.

- simplified label and chart structure.

  // wildcard host setting for the loadbalancer controller fulfilling this
  // Ingress, if left unspecified.
  // +optional
  repeated string hosts = 1;

  // SecretName is the name of the secret used to terminate SSL traffic on 443.
  // Field is left optional to allow SSL routing based on SNI hostname alone.
  // If the SNI host in a listener conflicts with the "Host" header field used