feat: running periodicaly peer exchange if discv5 is disabled

[gabrielmer]

Description

As part of

Use nwaku in runPeerExchangeLoop. Might not be necessary if nwaku already handles this?

in #3076, we are adding the functionality for nwaku edge nodes to periodically query Peer Exchange for new peers.

Currently the periodic search for peers is done by Discv5, so I activated the periodic Peer Exchange queries whenever Peer Exchange is enabled and Discv5 is disabled.

Let me know what you think, we could also create a flag to turn it on and off, but as we try not to add too many flags and over-complicate the configurations, I initially added it in this use case which should be the most common/logical.

Changes

• for edge nodes with Peer Exchange activated, query for peers every minute
• avoid exiting the program if first Peer Exchange request fails

[github-actions]

You can find the image built from this PR at

quay.io/wakuorg/nwaku-pr:3150

Built from a122086

[Ivansete-status]

Thanks for this! It will give a much more robust PX procedure 🥳

I've added a couple of comments that I hope you find reasonable ;P

[Ivansete-status]

Lovely! Thanks for it! 💯
I just added a nitpick comment

[NagyZoltanPeter]

Great extension, but unsure from where it will get PX service peer to provide peers instead of discv5. Maybe I overlooked sthg.

[NagyZoltanPeter]

If have no discv5 but want to use PX, how can we ensure to get some initial PX service peer?
Isn't it conf.peerExchangeNode setting ensure it?

[gabrielmer]

I tested it even without setting peerExchangeNode and worked :))

If there isn't a peerExchangeNode set, then any peer we have in the store with the PX codec is chosen randomly, so we just need to be connected to at least one peer that supports PX

nwaku/waku/node/peer_manager/peer_manager.nim

Lines 243 to 254 in b3656d6

	pm.serviceSlots.withValue(proto, serviceSlot):
	trace "Got peer from service slots",
	peerId = serviceSlot[].peerId, multi = serviceSlot[].addrs[0], protocol = proto
	return some(serviceSlot[])
	# If not slotted, we select a random peer for the given protocol
	if peers.len > 0:
	trace "Got peer from peerstore",
	peerId = peers[0].peerId, multi = peers[0].addrs[0], protocol = proto
	return some(peers[0])
	trace "No peer found for protocol", protocol = proto
	return none(RemotePeerInfo)

It can be any of our normal bootstrap nodes or a static node also.

Then, the peers we receive via PX if they also support it will enter to the pool from which we choose randomly, so it's just a matter of having a point where to start from, and luckily it must not necessarily be a configured peerExchangeNode :)