Fixes: #5396
This PR adds a proxy configuration stanza called expose. These flags register
listeners in Connect sidecar proxies to allow requests to specific HTTP paths from outside of the node. This allows services to protect themselves by only
listening on the loopback interface, while still accepting traffic from non
Connect-enabled services.
Under expose there is a boolean checks flag that would automatically expose all
registered HTTP and gRPC check paths.
This stanza also accepts a paths list to expose individual paths. The primary
use case for this functionality would be to expose paths for third parties like
Prometheus or the kubelet.
Listeners for requests to exposed paths are be configured dynamically at run
time. Any time a proxy, or check can be registered, a listener can also be
created.
In this initial implementation requests to these paths are not
authenticated/encrypted.
Also:
* Finished threading replaceExistingChecks setting (from GH-4905)
through service manager.
* Respected the original configSource value that was used to register a
service or a check when restoring persisted data.
* Run several existing tests with and without central config enabled
(not exhaustive yet).
* Switch to ioutil.ReadFile for all types of agent persistence.
* Add integration test for central config; fix central config WIP
* Add integration test for central config; fix central config WIP
* Set proxy protocol correctly and begin adding upstream support
* Add upstreams to service config cache key and start new notify watcher if they change.
This doesn't update the tests to pass though.
* Fix some merging logic get things working manually with a hack (TODO fix properly)
* Simplification to not allow enabling sidecars centrally - it makes no sense without upstreams anyway
* Test compile again and obvious ones pass. Lots of failures locally not debugged yet but may be flakes. Pushing up to see what CI does
* Fix up service manageer and API test failures
* Remove the enable command since it no longer makes much sense without being able to turn on sidecar proxies centrally
* Remove version.go hack - will make integration test fail until release
* Remove unused code from commands and upstream merge
* Re-bump version to 1.5.0
Freddy