## Discovery v5 update
In this update we remove the openssl dependency in favour of rust-crypto.
The update also removes a series of unnecessary async functions which may improve some of the issues we have been experiencing.
## Issue Addressed
NA
## Proposed Changes
Adds support for using the [`cross`](https://github.com/rust-embedded/cross) project to produce cross-compiled binaries using Docker images.
Provides quite clean and simple cross-compiles cause all the complexity is hidden in Dockerfiles. It does require you to be in the `docker` group though.
## Details
- Adds shortcut commands to `Makefile`
- Ensures `reqwest` and `discv5` use vendored openssl libs (i.e., static not shared).
- Switches to a [commit](284f705964) of blst that has a renamed C function to avoid a collision with openssl (upstream issue: https://github.com/supranational/blst/issues/21).
- Updates `ring` to the latest satisfiable version, since an earlier version was causing issues with `cross`.
- Off-topic, but adds extra message about Windows support as suggested by Discord user.
## Additional Info
- ~~Blocked on #1495~~
- There are no tests in CI for this yet for a few reasons:
- I'm hesitant to add more long-running tasks.
- Short-term bitrot should be avoided since we'll use it each release.
- In the long term I think it would be good to automate binary creation on a release.
- I observed the binaries increase in size from 50mb to 52mb after these changes.
## Issue Addressed
#1483
## Proposed Changes
Upgrades the log to a critical if a listener fails. We are able to listen on many interfaces so a single instance is not critical. We should however gracefully shutdown the client if we have no listeners, although the client can still function solely on outgoing connections.
For now a critical is raised and I leave #1494 for more sophisticated handling of this.
This also updates discv5 to handle errors of binding to a UDP socket such that lighthouse is now able to handle them.
## Issue Addressed
Some nodes not following head, high CPU usage and HTTP API delays
## Proposed Changes
Patches gossipsub. Gossipsub was using an `lru_time_cache` to check for duplicates. This contained an `O(N)` lookup for every gossipsub message to update the time cache. This was causing high cpu usage and blocking network threads.
This PR introduces a custom cache without `O(N)` inserts.
This also adds built in safety mechanisms to prevent gossipsub from excessively retrying connections upon failure. A maximum limit is set after which we disconnect from the node from too many failed substream connections.
## Issue Addressed
NA
## Proposed Changes
- Moves the git-based versioning we were doing into the `lighthouse_version` crate in `common`.
- Removes the `beacon_node/version` crate, replacing it with `lighthouse_version`.
- Bumps the version to `v0.2.0`.
## Additional Info
There are now two types of version string:
1. `const VERSION: &str = Lighthouse/v0.2.0-1419501f2+`
1. `version_with_platform() = Lighthouse/v0.2.0-1419501f2+/x86_64-linux`
(1) is handy cause it's a `const` and shorter. (2) has platform info so it's more useful. Note that the plus-sign (`+`) indicates the the git commit is dirty (it used to be `(modified)` but I had to shorten it to fit into graffiti).
These version strings are now included on:
- `lighthouse --version`
- `lcli --version`
- `curl localhost:5052/node/version`
- p2p messages when we communicate our version
You can update the version by changing this constant (version is not related to a `Cargo.toml`):
b9ad7102d5/common/lighthouse_version/src/lib.rs (L4-L15)
## Issue Addressed
The most recent gossipsub update had an issue where some privacy settings lead to not sending a sequence number with the message. Although Lighthouse treats these as valid (based on current configuration) other clients may not.
This corrects gossipsub to send sequence numbers where expected and based on the configuration settings.
## Issue Addressed
N/A
## Proposed Changes
This provides a number of corrections and improvements to gossipsub. Specifically
- Enables options for greater privacy around the message author
- Provides greater flexibility on message validation
- Prevents unvalidated messages from being gossiped
- Shifts the duplicate cache to a time-based cache inside gossipsub
- Updates the message-id to handle bytes
- Bug fixes related to mesh maintenance and topic subscription. This should improve our attestation inclusion rate.
Downgrades libp2p and the gossipsub updates.
This looks to resolve the CPU usage issue we have been seeing.
The root cause is likely inside the latest gossipsub updates, which will be addressed in a later PR
