This stable release fixes an issue where the destination service is t…

…hrottled

after overwhelming the Kubernetes API server with node topology queries. This
results in the destination service failing requests and spiking in latency. By
moving to a shared informer for these queries, the information is now fetched
asynchronously.

This edge release adds a new `--short` flag to `linkerd check` to show a

summary of the check output. This release also includes various proxy bug fixes
and improvements.

* Proxy
  * Fixed a task leak that would be triggered when clients disconnect a
    service in failfast.
  * Improved admin server protocol detection so that error messages are
    more descriptive about the underlying problem.
  * Fixed panics found in fuzz testing. These panics were extremely
    unlikely to occur in practice and would require very specific
    configuration overrides to be triggered.
* CLI
  * Added support for a `--short` flag to the check command to output a summary
    of check results

This edge release further consolidates the control plane by removing the

linkerd-controller deployment and moving the sp-validator container into the
destination deployment.

Annotation inheritance has been added so that all Linkerd annotations
on a namespace resource will be inherited by pods within that namespace.
In addition, the `config.linkerd.io/proxy-await` annotation has been added which
enables the [linkerd-await](https://github.com/linkerd/linkerd-await)
functionality by default, simplifying the implementation of the await behavior.
Setting the annotation value to disabled will prevent this behavior.

Some of the `linkerd check` functionality has been updated. The command
ensures that annotations and labels are properly located in the YAML and adds
proxy checks for the control plane and extension pods.

Finally, the nginx container has been removed from the Multicluster gateway pod,
which will impact upgrades. Please see the note below.

**Upgrade note:** When the Multicluster extension is updated in both of the
source and target clusters there won't be any downtime because this change only
affects the readiness probe. The multicluster links must be re-generated with
the `linkerd mc link` command and the `linkerd mc gateways` will show
the target cluster as not alive until the `linkerd mc link` command is re-run,
however that shouldn't affect existing endpoints pointing to the target cluster.

* Added proxy checks for core control plane and extension pods
* Added support for awaiting proxy readiness using an annotation
* Added namespace annotation inheritance to pods
* Removed the linkerd-controller pod
* Moved sp-validator container into the destination deployment
* Added check verifying that labels and annotations are not mixed up
  (thanks @Szymongib)
* Enabled support for extra initContainers to the linkerd-cni daemonset
  (thanks @mhulscher!)
* Removed nginx container from multicluster gateway pod
* Added an error message when there is nothing to uninstall

This stable release adds CLI support for Apple Silicon M1 chips and s…

…upport for

SMI's TrafficSplit `v1alpha2`.

There are several proxy fixes: handling `FailedPrecondition` errors gracefully,
inbound TLS detection from non-meshed workloads, and using the correct cached
client when the proxy is in ingress mode. The logging infrastructure has also
been improved to reduce memory pressure in high-connection environments.

On the control-plane side, there have been several improvements to the
destination service such as support for Host IP lookups and ignoring pods
in "Terminating" state. It also updates the proxy-injector to add opaque ports
annotation to pods if their namespace has it set.

On the CLI side, `linkerd repair` has been updated to be aware about the control-plane
version and suggest the relevant version to generate the right config. Various
bugs have been fixed around `linkerd identity`, etc.

**Upgrade notes**: Please refer [2.10 upgrade instructions](https://linkerd.io/2/tasks/upgrade/#upgrade-notice-stable-2100)
if you are upgrading from `2.9.x` or below versions.

* Proxy:
  * Fixed an issue where proxies could infinitely retry failed requests to the
    `destination` controller when it returned a `FailedPrecondition`
  * The proxy's logging infrastructure has been updated to reduce memory pressure
    in high-connection environments.
  * Fixed a caching issue in the outbound proxy that would cause it to
    forward traffic to the wrong pod when running in ingress mode.
  * Fixed an issue where inbound TLS detection from non-meshed workloads
    could break
  * Fixed an issue where the admin server's HTTP detection would fail and
    not recover; these are now handled gracefully and without logging warnings
  * Control plane proxies no longer emit warnings about the resolution stream ending.
    This error was innocuous.
  * Bumped the proxy-init image to v1.3.11 which updates the go version to be 1.16.2

* Control Plane:
  * Fixed an issue where the destination service would respond with too big of a
    header and result in http2 protocol errors
  * Fixed an issue where the destination control plane component sometimes returned
    endpoint addresses with a 0 port number while pods were undergoing a rollout
    (thanks @riccardofreixo!)
  * Fixed an issue where pod lookups by host IP and host port fail even though
    the cluster has a matching pod
  * Updated the IP Watcher in destination to ignore pods in "Terminating" state
    (thanks @Wenliang-CHEN!)
  * Modified the proxy-injector to add the opaque ports annotation to pods
    if their namespace has it set
  * Added Support for TrafficSplit `v1alpha2`
  * Updated all the control-plane components to use go `1.16.2`.

* CLI:
  * Fixed an issue where the linkerd identity command returned the root
    certificate of a pod instead of its leaf certificates
  * Fixed an issue where the destination service would respond with too
    big of a header and result in http2 protocol errors
  * Updated the release process to build Linkerd CLI binaries for Apple
    Silicon M1 chips
  * Improved error messaging when trying to install Linkerd on a cluster
    that already had Linkerd installed
  * Added a loading spinner to the linkerd check command when running
    extension checks
  * Added installNamespace toggle in the jaeger extension's install.
    (thanks @jijeesh!)
  * Updated healthcheck pkg to have hintBaseURL configurable, useful
    for external extensions using that pkg
  * Fixed TCP read and write bytes/sec calculations to group by label
    based off inbound or outbound traffic
  * Fixed an issue in linkerd inject where the wrong annotation would
    be added when using --ingress flag
  * Updated `linkerd repair` to be aware of the client and server versions
  * Updated `linkerd uninstall` to print error message when there are no
    resources to uninstall.

* Helm:
  * Aligned the Helm installation heartbeat schedule to match that of the CLI

* Viz:
  * Fixed an issue where the topology graph in the dashboard was no
    longer draggable.
  * Updated dashboard build to use webpack v5
  * Added CA certs to the Viz extension's metrics-api container so
    that it can validate the certifcate of an external Prometheus
  * Removed components from the control plane dashboard that now
    are part of the Viz extension
  * Changed web's base image from debian to scratch

* Multicluster:
  * Fixed an issue with Multicluster's service mirror where its endpoint
    repair retries were not properly rate limited

* Jaeger:
  * Fixed components in the Jaeger extension to set the correct Prometheus
    scrape values

This edge supersedes `edge-21.4.2` as a release candidate for `stable…

…-2.10.1`!

This release adds support for TrafficSplit `v1alpha2`. Additionally, It includes
improvements to the web and `proxy-init` images.

* Added Support for TrafficSplit `v1alpha2`
* Changed web base image from debian to scratch
* Bumped the `proxy-init` image to `v1.3.11` which updates
  the go version to be `1.16.2`

This edge release is another candidate for `stable-2.10.1`!

It includes some CLI fixes and addresses an issue where the outbound proxy
would forward traffic to the wrong pod when running in ingress mode.

Thank you to all of our users that have helped test and identify issues in 2.10!

* Fixed an issue in `linkerd inject` where the wrong annotation would be
  added when using `--ingress` flag
* Fixed a nil pointer dereference in `linkerd repair` caused by a mismatch
  between CLI and server versions
* Removed an unnecessary error handling condition in multicluster check
  (thanks @wangchenglong01!)
* Fixed a caching issue in the outbound proxy that would cause it to
  forward traffic to the wrong pod when running in ingress mode.
* Removed unsupported `matches` field from TrafficSplit CRD

This is a release candidate for `stable-2.10.1`!

This includes several fixes for the core installation as well the Multicluster,
Jaeger, and Viz extensions. There are two significant proxy fixes that address
TLS detection and admin server failures.

Thanks to all our 2.10 users who helped discover these issues!

* Fixed TCP read and write bytes/sec calculations to group by label based off
  inbound or outbound traffic
* Updated dashboard build to use webpack v5
* Modified the proxy-injector to add the opaque ports annotation to pods if
  their namespace has it set
* Added CA certs to the Viz extension's `metrics-api` container so that it can
  validate the certifcate of an external Prometheus
* Fixed an issue where inbound TLS detection from non-meshed workloads could
  break
* Fixed an issue where the admin server's HTTP detection would fail and not
  recover; these are now handled gracefully and without logging warnings
* Aligned the Helm installation heartbeat schedule to match that of the CLI
* Fixed an issue with Multicluster's serivce mirror where it's endpoint repair
  retries were not properly rate limited
* Removed components from the control plane dashboard that now are part of the
  Viz extension
* Fixed components in the Jaeger extension to set the correct Prometheus scrape
  values

This release fixes some issues around publishing of CLI binary

for Apple Silicon M1 Chips. This release also includes some fixes and
improvements to the dashboard, destination, and the CLI.

* Fixed an issue where the topology graph in the dashboard was no longer
  draggable
* Updated the IP Watcher in destination to ignore pods in "Terminating" state
  (thanks @Wenliang-CHEN!)
* Added `installNamespace` toggle in the jaeger extension's install.
  (thanks @jijeesh!)
* Updated `healthcheck` pkg to have `hintBaseURL` configurable, useful
  for external extensions using that pkg
* Added multi-arch support for RabbitMQ integration tests (thanks @barkardk!)

This release includes various bug fixes and improvements to the CLI, the

identity and destination control plane components as well as the proxy. This
release also ships with a new CLI binary for Apple Silicon M1 chips.

* Added new RabbitMQ integration tests (thanks @barkardk!)
* Updated the Go version to 1.16.2
* Fixed an issue where the `linkerd identity` command returned the root
  certificate of a pod instead of its leaf certificate
* Fixed an issue where the destination service would respond with too big of a
  header and result in http2 protocol errors
* Updated the release process to build Linkerd CLI binaries for Apple Silicon
  M1 chips
* Improved error messaging when trying to install Linkerd on a cluster that
  already had Linkerd installed
* Fixed an issue where the `destination` control plane component sometimes
  returned endpoint addresses with a `0` port number while pods were
  undergoing a rollout (thanks @riccardofreixo!)
* Added a loading spinner to the `linkerd check` command when running extension
  checks
* Fixed an issue where pod lookups by host IP and host port fail even though
  the cluster has a matching pod
* Control plane proxies no longer emit warnings about the resolution stream
  ending. This error was innocuous.
* Fixed an issue where proxies could infinitely retry failed requests to the
  `destination` controller when it returned a `FailedPrecondition`
* The proxy's logging infrastructure has been updated to reduce memory pressure
  in high-connection environments.

This release introduces Linkerd extensions. The default control plane…

… no longer

includes Prometheus, Grafana, the dashboard, or several other components that
previously shipped by default.  This results in a much smaller and simpler set
of core functionalities.  Visibility and metrics functionality is now available
in the Viz extension under the `linkerd viz` command.  Cross-cluster
communication functionality is now available in the Multicluster extension
under the `linkerd multicluster` command.  Distributed tracing functionality is
now available in the Jaeger extension under the `linkerd jaeger` command.

This release also introduces the ability to mark certain ports as "opaque",
indicating that the proxy should treat the traffic as opaque TCP instead of
attempting protocol detection.  This allows the proxy to provide TCP metrics
and mTLS for server-speaks-first protocols.  It also enables support for
TCP traffic in the Multicluster extension.

**Upgrade notes**: Please see the [upgrade
instructions](https://linkerd.io/2/tasks/upgrade/#upgrade-notice-stable-2100).

* Proxy
  * Updated the proxy to use TLS version 1.3; support for TLS 1.2 remains
    enabled for compatibility with prior proxy versions
  * Improved support for server-speaks-first protocols by allowing ports to be
    marked as opaque, causing the proxy to skip protocol detection.  Ports can
    be marked as opaque by setting the `config.linkerd.io/opaque-ports`
    annotation on the Pod and Service or by using the `--opaque-ports` flag with
    `linkerd inject`
  * Ports `25,443,587,3306,5432,11211` have been removed from the default skip
    ports; all traffic through those ports is now proxied and handled opaquely
    by default
  * Fixed an issue that could cause proxies in "ingress mode"
    (`linkerd.io/inject: ingress`) to use an excessive amount of memory
  * Improved diagnostic logging around "fail fast" and "max-concurrency
    exhausted" error messages
  * Added a new `/shutdown` admin endpoint that may only be accessed over the
    loopback network allowing batch jobs to gracefully terminate the proxy on
    completion

* Control Plane
  * Removed all components and functionality related to visibility, tracing,
    or multicluster.  These have been moved into extensions
  * Changed the identity controller to receive the trust anchor via environment
    variable instead of by flag; this allows the certificate to be loaded from a
    config map or secret (thanks @mgoltzsche!)
  * Added PodDisruptionBudgets to the control plane components so that they
    cannot be all terminated at the same time during disruptions
    (thanks @tustvold!)

* CLI
  * Changed the `check` command to include each installed extension's `check`
    output; this allows users to check for proper configuration and installation
    of Linkerd without running a command for each extension
  * Moved the `metrics`, `endpoints`, and `install-sp` commands into subcommands
    under the `diagnostics` command
  * Added an `--opaque-ports` flag to `linkerd inject` to easily mark ports
    as opaque.
  * Added the `repair` command which will repopulate resources needed for
    properly upgrading a Linkerd installation
  * Added Helm-style `set`, `set-string`, `values`, `set-files` customization
    flags for the `linkerd install` and `linkerd upgrade` commands
  * Introduced the `linkerd identity` command, used to fetch the TLS certificates
    for injected pods (thanks @jimil749)
  * Removed the `get` and `logs` command from the CLI

* Helm
  * Changed many Helm values, please see the upgrade notes

* Viz
  * Introduced the `linkerd viz` subcommand which contains commands for
    installing the viz extension and all visibility commands
  * Updated the Web UI to only display the "Gateway" sidebar link when the
    multicluster extension is active
  * Added a `linkerd viz list` command to list pods with tap enabled
  * Fixed an issue where the `tap` APIServer would not refresh its certs
    automatically when provided externally—like through cert-manager

* Multicluster
  * Introduced the `linkerd multicluster` subcommand which contains commands for
    installing the multicluster extension and all multicluster commands
  * Added support for cross-cluster TCP traffic
  * Updated the service mirror controller to copy the
    `config.linkerd.io/opaque-ports` annotation when mirroring services so that
    cross-cluster traffic can be correctly handled as opaque
  * Added support for multicluster gateways of types other than LoadBalancer
    (thanks @DaspawnW!)

* Jaeger
  * Introduced the `linkerd jaeger` subcommand which contains commands for
    installing the jaeger extension and all tracing commands
  * Added a `linkerd jaeger list` command to list pods with tracing enabled

This release includes changes from a massive list of contributors. A special
thank-you to everyone who helped make this release possible:
[Lutz Behnke](https://github.com/cypherfox)
[Björn Wenzel](https://github.com/DaspawnW)
[Filip Petkovski](https://github.com/fpetkovski)
[Simon Weald](https://github.com/glitchcrab)
[GMarkfjard](https://github.com/GMarkfjard)
[hodbn](https://github.com/hodbn)
[Hu Shuai](https://github.com/hs0210)
[Jimil Desai](https://github.com/jimil749)
[jiraguha](https://github.com/jiraguha)
[Joakim Roubert](https://github.com/joakimr-axis)
[Josh Soref](https://github.com/jsoref)
[Kelly Campbell](https://github.com/kellycampbell)
[Matei David](https://github.com/mateiidavid)
[Mayank Shah](https://github.com/mayankshah1607)
[Max Goltzsche](https://github.com/mgoltzsche)
[Mitch Hulscher](https://github.com/mhulscher)
[Eugene Formanenko](https://github.com/mo4islona)
[Nathan J Mehl](https://github.com/n-oden)
[Nicolas Lamirault](https://github.com/nlamirault)
[Oleh Ozimok](https://github.com/oleh-ozimok)
[Piyush Singariya](https://github.com/piyushsingariya)
[Naga Venkata Pradeep Namburi](https://github.com/pradeepnnv)
[rish-onesignal](https://github.com/rish-onesignal)
[Shai Katz](https://github.com/shaikatz)
[Takumi Sue](https://github.com/tkms0106)
[Raphael Taylor-Davies](https://github.com/tustvold)
[Yashvardhan Kukreja](https://github.com/yashvardhan-kukreja)