## Issue Addressed
#4150
## Proposed Changes
Maintain trusted peers in the pruning logic. ~~In principle the changes here are not necessary as a trusted peer has a max score (100) and all other peers can have at most 0 (because we don't implement positive scores). This means that we should never prune trusted peers unless we have more trusted peers than the target peer count.~~
This change shifts this logic to explicitly never prune trusted peers which I expect is the intuitive behaviour.
~~I suspect the issue in #4150 arises when a trusted peer disconnects from us for one reason or another and then we remove that peer from our peerdb as it becomes stale. When it re-connects at some large time later, it is no longer a trusted peer.~~
Currently we do disconnect trusted peers, and this PR corrects this to maintain trusted peers in the pruning logic.
As suggested in #4150 we maintain trusted peers in the db and thus we remember them even if they disconnect from us.
* Update Engine API to Latest
* Get Mock EE Working
* Fix Mock EE
* Update Engine API Again
* Rip out get_blobs_bundle Stuff
* Fix Test Harness
* Fix Clippy Complaints
* Fix Beacon Chain Tests
It is a well-known fact that IP addresses for beacon nodes used by specific validators can be de-anonymized. There is an assumed risk that a malicious user may attempt to DOS validators when producing blocks to prevent chain growth/liveness.
Although there are a number of ideas put forward to address this, there a few simple approaches we can take to mitigate this risk.
Currently, a Lighthouse user is able to set a number of beacon-nodes that their validator client can connect to. If one beacon node is taken offline, it can fallback to another. Different beacon nodes can use VPNs or rotate IPs in order to mask their IPs.
This PR provides an additional setup option which further mitigates attacks of this kind.
This PR introduces a CLI flag --proposer-only to the beacon node. Setting this flag will configure the beacon node to run with minimal peers and crucially will not subscribe to subnets or sync committees. Therefore nodes of this kind should not be identified as nodes connected to validators of any kind.
It also introduces a CLI flag --proposer-nodes to the validator client. Users can then provide a number of beacon nodes (which may or may not run the --proposer-only flag) that the Validator client will use for block production and propagation only. If these nodes fail, the validator client will fallback to the default list of beacon nodes.
Users are then able to set up a number of beacon nodes dedicated to block proposals (which are unlikely to be identified as validator nodes) and point their validator clients to produce blocks on these nodes and attest on other beacon nodes. An attack attempting to prevent liveness on the eth2 network would then need to preemptively find and attack the proposer nodes which is significantly more difficult than the default setup.
This is a follow on from: #3328
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
Co-authored-by: Paul Hauner <paul@paulhauner.com>
