feat(destination): advertise identity for pods meshed by any control plane - #1
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…plane The destination controller only advertised a `TlsIdentity` for a pod when the pod's control-plane-ns label matched the controller's own namespace. As a result, a pod meshed by a *different* Linkerd control plane was reported as unmeshed (no identity), even when all control planes share a trust root. This blocks the proxy's outbound default policy (`all-authenticated` / `cluster-authenticated`), which requires mTLS to targets that advertise a mesh identity: pods meshed by a peer control plane would be refused even though they are meshed. Relax the identity gate from `controllerNSLabel == controllerNS` to `controllerNSLabel != ""`, matching the protocol-hint gate immediately above it. The identity SAN is already built from the pod's own control-plane-ns label, so under a shared trust root it is correct for cross-control-plane peers with no further change. This leaves the threaded `controllerNS` value unused in the endpoint translators, so it is removed from `newEndpointTranslator`, `newEndpointProfileTranslator` and `createWeightedAddr` and their call sites (`Config.ControllerNS` is unchanged). This assumes a single shared trust root/domain across all control planes (Variant A). Selectively trusting meshes with distinct trust roots (via a trust-domain annotation) remains future work, as noted in the TODO. Adds a test asserting identity is advertised for a pod whose control-plane-ns differs from the controller's, with a SAN derived from the pod's own label, and documents the shared-root requirement on the `defaultOutboundPolicy` Helm value. Relates to linkerd#15615 Relates to linkerd/linkerd2-proxy#4617 Signed-off-by: Alex Klein <alex@codesphere.com>
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The destination controller only advertised a TlsIdentity for a pod when the pod's control-plane-ns label matched the controller's own namespace. As a result, a pod meshed by a different Linkerd control plane was reported as unmeshed (no identity), even when all control planes share a trust root.
This blocks the proxy's outbound default policy (
all-authenticated/cluster-authenticated), which requires mTLS to targets that advertise a mesh identity: pods meshed by a peer control plane would be refused even though they are meshed.Relax the identity gate from
controllerNSLabel == controllerNStocontrollerNSLabel != "", matching the protocol-hint gate immediately above it. The identity SAN is already built from the pod's own control-plane-ns label, so under a shared trust root it is correct for cross-control-plane peers with no further change. This leaves the threadedcontrollerNSvalue unused in the endpoint translators, so it is removed fromnewEndpointTranslator,newEndpointProfileTranslatorandcreateWeightedAddrand their call sites (Config.ControllerNSis unchanged).This assumes a single shared trust root/domain across all control planes (Variant A). Selectively trusting meshes with distinct trust roots (via a trust-domain annotation) remains future work, as noted in the TODO.
Adds a test asserting identity is advertised for a pod whose control-plane-ns differs from the controller's, with a SAN derived from the pod's own label, and documents the shared-root requirement on the
defaultOutboundPolicyHelm value.Relates to linkerd#15615
Relates to linkerd/linkerd2-proxy#4617