Release notes for Serving 1.9

Changelog since 1.8

Knative will now warn (but not error) when creating or updating a PodSpec
where containers have additional privilege due to unset SecurityContext values.
Explicitly setting these values to any setting, including high-privilege ones,
will disable this warning.
These fields are:
- runAsNonRoot (empty means false)
- allowPrivilegeEscalation (empty means true)
- seccompProfile.type (empty string means Unconfined)
- capabilities.drop (default maintains privileges, use ALL to drop unneeded linux capabilities) (#13399, @evankanderson)
Adds the secure-pod-defaults feature, which is defaulted to Disabled in
this release.
When enabled, containers described by users will have best-practice
SecurityContext features enabled unless insecure settings are specifically
requested. (#13398, @evankanderson)
Work around for cert-manager not allowing us to create certs for 64+ bytes name ksvc (#13569, @KauzClay)
Autoscaler now runs a single leader election go routine (#13585, @dprotaso)

Add app label to Service selector for webhook and domainmapping-webhook. (#13265, @a7i)
Upgrade tests now stream logs from user and system namespace. The logs are printed on failure. (#13587, @mgencur)

Changes to Pod or Revision-level defaults during Knative upgrades will no longer be attempted (and failed) when supplying your own Revision name. (#13565, @evankanderson)

Nothing has changed.

Nothing has changed.