Automatic merge from submit-queue
Cache Webhook Authentication responses
Add a simple LRU cache w/ 2 minute TTL to the webhook authenticator.
Kubectl is a little spammy, w/ >= 4 API requests per command. This also prevents a single unauthenticated user from being able to DOS the remote authenticator.
A few months ago we refactored options to keep it independent of the
implementations, so that it could be used in CLI tools to validate
config or to generate config, without pulling in the full dependency
tree of the master. This change restores that by separating
server_run_options.go back to its own package.
Also, options structs should never contain non-serializable types, which
storagebackend.Config was doing with runtime.Codec. Split the codec out.
Fix a typo on the name of the etcd2.go storage backend.
Finally, move DefaultStorageMediaType to server_run_options.
Automatic merge from submit-queue
Webhook Token Authenticator
Add a webhook token authenticator plugin to allow a remote service to make authentication decisions.
The codec factory should support two distinct interfaces - negotiating
for a serializer with a client, vs reading or writing data to a storage
form (etcd, disk, etc). Make the EncodeForVersion and DecodeToVersion
methods only take Encoder and Decoder, and slight refactoring elsewhere.
In the storage factory, use a content type to control what serializer to
pick, and use the universal deserializer. This ensures that storage can
read JSON (which might be from older objects) while only writing
protobuf. Add exceptions for those resources that may not be able to
write to protobuf (specifically third party resources, but potentially
others in the future).
Automatic merge from submit-queue
Use correct defaults when binding apiserver flags
defaults should be set in the struct-creating function, then the current struct field value used as the default when binding the flag
Automatic merge from submit-queue
Make etcd cache size configurable
Instead of the prior 50K limit, allow users to specify a more sensible size for their cluster.
I'm not sure what a sensible default is here. I'm still experimenting on my own clusters. 50 gives me a 270MB max footprint. 50K caused my apiserver to run out of memory as it exceeded >2GB. I believe that number is far too large for most people's use cases.
There are some other fundamental issues that I'm not addressing here:
- Old etcd items are cached and potentially never removed (it stores using modifiedIndex, and doesn't remove the old object when it gets updated)
- Cache isn't LRU, so there's no guarantee the cache remains hot. This makes its performance difficult to predict. More of an issue with a smaller cache size.
- 1.2 etcd entries seem to have a larger memory footprint (I never had an issue in 1.1, even though this cache existed there). I suspect that's due to image lists on the node status.
This is provided as a fix for #23323
Lucas Käldström