## edge-21.9.2

This edge release gets us closer to 2.11 by further polishing the policy
feature. Also the proxy received a noticeable resource consumption improvement.

* Stopped creating the default authorizations for the kubelet
* Added missing ports to the destination controller's default list of ports, to
  allow the sp-validator to start properly when using a default-deny policy
* Set the destination and proxy-injector pods default policy to
  `all-unauthenticated` to allow the webhooks to be called from the kube-api
  when using a default-deny policy
* Extended inbound policies to cover the proxy's admin server
* Improved the proxy's error handling so that HTTP metrics include 5XX responses
  for common errors
* The proxy's outbound tap has been fixed to include route labels when service
  profiles are configured
* Enabled link-time optimizations in the Rust components (proxy and policy
  controller), resulting in noticeable RSS and CPU consumption improvements
* Made the admin servers in the control plane components properly shut down
  (thanks @EpicStep!)
* Updated linkerd-await, suppressing the error emitted when linkerd-await was
  disabled

This release includes various improvements and feature additions acro…

…ss the policy

feature i.e, New validating webhook for policy resources. This also includes changes
in the proxy i.e, terminating TCP connections when a authorization is revoked, improvements
in the proxy authorization metrics. In addition, proxy injector has also been updated
to set the right `opaque-ports` annotation on services with default opaque ports.

* Added a new validating admission controller to validate the policy resources
* Updated the proxy-init to remove a rule which caused the packets from the proxy
  with destination != 127.0.0.1 on localhost to be sent to the inbound proxy
* Updated inbound policy enforcement to interrupt TCP forwarding if a previously
  established authorization is revoked
* Added new proxy metrics to expose authorization decisions
* Updated inbound TCP metrics to only include a `srv_name` label
* Updated the proxy to export route-oriented metrics only when a ServiceProfile
  is enabled
* Updated the proxy's release build configuration to improve CPU and memory
  utilization
* Added DNS name validation to the `proxy-identity` binary which creates the
  read-only private key required by the proxy (thanks @yorkijr!)
* Updated the identity controller's default policy to be `cluster-unauthenticated`
* Updated the proxy injector to include the correct default ports as opaque with
  services
* Deprecated the usage of `vis stat ts` and print a warning about the SMI extension
* Updated various dependencies across the dashboard, policy-controller
  (thanks @dependabot!)

This edge release continues to build on the policy feature by adding …

…support for

cluster-scoped default policies and exposing policy labels on various prometheus
metrics. The proxy has been updated to return HTTP-level authorization errors
at the time that the request is processed, instead of when the connection is
established.

In addition, the proxy-injector has been updated to set the `opaque-ports`
annotation on a workload to make sure that controllers can discover how the
workload was configured. Also, the `sleep` binary has been added to the proxy
image in order to restore the functionality required for `waitBeforeExitSeconds`
to work.

* Added `default-inbound-policy` annotation to the proxy-injector
* Updated the proxy-injector to always add the `opaque-ports` annotation
* Added `sleep` binary to proxy image
* Updated inbound traffic metrics to include server and authorization labels
* Updated the policy-controller to honor pod level port annotations when a
  `Server` resource definition does not match the ports defined for the workload
* Updated the point at which the proxy returns HTTP-level authorization errors
* Exposed permit and policy labels on HTTP metrics
* Added support for cluster-scoped default policies
* Dropped `nonroot` variant from the policy-controller's distroless base image
  to avoid erroring in some environments.

This release adds support for dynamic inbound policies. The proxy now…

… discovers

policies from the policy-controller API for all application ports documented in a
pod spec. Rejected connections are logged. Policies are not yet reflected in the
proxy's metrics.

These policies also allow the proxy to skip protocol detection when a server is
explicitly annotated as HTTP/2 or when the server is documented to be opaque or
application-terminated TLS.

* Added a new section to linkerd-viz's dashboard that lists installed extensions
  (thanks @sannimichaelse!)
* Added the `enableHeadlessServices` Helm flag to the `linkerd multicluster
  link` command for enabling headless service mirroring (thanks @knutgoetz!)
* Removed some unused and duplicate constants in the codebase (thanks
  @xichengliudui!)
* Added support for exposing service metadata from exported to mirrored services
  in multicluster installations (thanks @importhuman!)
* Fixed an issue where the policy controller's liveness checks would fail after
  the controller was disconnected but had successfully resumed its watches
* Fixed the `linkerd-policy` service selector to properly select `destination`
  control plane components
* Added additional environment variables to the proxy container to allow support
  for dynamic policy configuration

This edge release continues the policy work by adding a new controlle…

…r, written

in Rust, to expose a discovery API for inbound server policies. Apart from
that, this release includes a number of changes from external contributors; the
`linkerd-jaeger` helm chart now supports passing arguments to the Jaeger
container through the chart's values file. A number of unused functions and
variables have been also removed to improve the quality of the codebase.
Finally, this release also comes with changes to the proxy's outbound behavior,
a new extensions page on the dashboard, and support for querying service
metrics using the `authority` label in `linkerd viz stat`.

* Introduced new `linkerd-policy-controller`; the new controller is written in
  Rust and implements discovery APIs for inbound server policies, the container
  has been added to the `linkerd-destination` pod
* Updated `linkerd-jaeger` helm chart to support passing arguments to the
  Jaeger container (thanks @bsord!)
* Added support for querying service metrics using the `authority` label in
  `linkerd viz stat`
* Improved code hygiene by removing unused constants and functions throughout
  the codebase (thanks @xichengliudui!)
* Added a new extensions page to the dashboard to list all known built-in and
  third party extensions that can be used with Linkerd
* Changed outbound behavior in the proxy to tear down server-side connections
  when the remote proxy returns responses that indicate proxy errors; the
  connection in this case will be reset to allow clients to connect to a new
  endpoint

## edge-21.8.1

This releases includes initial changes w.r.t addition of Authorization into
Linkerd. It includes adding the new `policy.linkerd.io` CRDs to the core install.
This also includes numerous dependency updates both in the web and dashboard.

* Added `servers.policy.linkerd.io` and `serverauthorizations.policy.linkerd.io`
  CRDs into the default Linkerd installation to support configuration and
  discovery of inbound policies
* Modified the proxy to support upcoming policy features
* Updated several dashboard dependencies to latest versions
* Updated several proxy dependencies to latest versions

This release updates Linkerd to store the identity trust root in a Co…

…nfigMap to

make it easier to manage and rotate the trust root.  The release also lays the
groundwork for StatefulSet support in the multicluster extension and removes
deprecated PSP resources by default.

* Added a `linkerd-identity-trust-roots` ConfigMap which contains the configured
  trust root bundle
* Introduced support for StatefulSets across multicluster (disabled by default)
* Stopped installing PSP resources by default since these are deprecated as
  of Kubernetes v1.21

This release continues to focus on dependency updates. It also adds the

`l5d-proxy-error` information header to distinguish proxy generated errors
proxy generated errors from application generated errors.

* Updated several project dependencies
* Added a new `l5d-proxy-error` on responses that allows proxy-generated error
  responses to be distinguished from application-generated error responses.
* Removed support for configuring HTTP/2 keepalives via the proxy.
  Configuring this setting would sometimes cause conflicts with Go gRPC servers
  and clients
* Added a new `target_addr` label to `*_tcp_accept_errors` metrics to improve
  diagnostics, especially for TLS detection timeouts

This edge release introduces several changes around metrics. ReplicaS…

…ets are now

a supported resource and metrics can be associated with them. A new metric has
been added which counts proxy errors encountered before a protocol can be
detected. Finally, the request errors metric has been split into separate
inbound and outbound directions.

* Fixed printing `check --pre` command usage if it fails after being unable to
  connect to Kubernetes (thanks @rdileep13!)
* Updated the default skip and opaque ports to match that which is listed in the
  [documentation](https://linkerd.io/2.10/features/protocol-detection/#configuring-protocol-detection)
* Added the `LINKERD2_PROXY_INBOUND_PORTS` environment variable during proxy
  injection which will be used by ongoing policy changes
* Added client-go cache size metrics to the `diagnostics controller-metrics`
  command
* Added validation that the certificate provided by an external issuer is a CA
  (thanks @rumanzo!)
* Added metrics support for ReplicaSets
* Replaced the `request_errors_total` metric with two new metrics:
  `inbound_http_errors_total` and `outbound_http_errors_total`
* Introduced the `inbound_tcp_accept_errors_total` and
  `outbound_tcp_accept_errors_total` metrics which count proxy errors
  encountered before a protocol can be detected

This edge release focuses on dependency updates and has a couple of f…

…unctional

changes. First, the Dockerfile used to build the proxy has been updated to use
the default `distroless` image, rather than the non-root variant. This change
is safe because the proxy already runs as non-root within the container. Second,
the `ignoreInboundPorts` parameter has been added in the linkerd2-cni helm
charts in order to enable tap support.

* Updated several project dependencies
* Updated the Dockerfile-proxy to use the default distroless image, because
  the proxy already runs as non-root within the container
* Added `ignoreInboundPorts` parameter to the linkerd2-cni plugin helm chart