Would it be possible to have some form of master index (replicated across instances - not a centralized service) along with a public standard for registering an instance/community on the index?
Sure, this and anything else is possible as long as people have the motivation and knowledge to pursue and implement it.
Something similar to DNS standards could work for Fediverse sites. In fact, why not piggyback on DNS like the SPF, DKIM, DMARC, and even openpgp4fpr / KeyOxide standards. DNS itself fulfills the first two requirements:
Some form of “master index” - check! ✅
Replicated across “instances” - check! ✅ … in a sense …
If you consider: Zone Transfer / AXFR a form of “replication”
If you consider DNS servers a “node” / “instance”… rather than just a Lemmy/Kbin/Fediverse “instance”
For the second point about DNS zone transfer… it used to be the case that anyone could issue the AXFR request to a DNS server. However, this basically dumps all the records on a DNS server’s zonefile for that domain. So, it’s often disallowed nowadays because it discloses all hosts in the zone file, some of which might be considered private by the domain owner. Instead, server admins usually configure this to only be allowed by trusted IP addresses of other hosts. (I guess it’s a very crude form of “web of trust” based on IP allow lists and the whims of a SysAdmin.)
Maybe the Fediverse has use for piggybacking on DNS via TXT records for some use cases. However, it’s likely that some other decentralized method of replication might be invented specifically for federation with other ActivityPub servers.
Sure, this and anything else is possible as long as people have the motivation and knowledge to pursue and implement it.
Something similar to DNS standards could work for Fediverse sites. In fact, why not piggyback on DNS like the SPF, DKIM, DMARC, and even openpgp4fpr / KeyOxide standards. DNS itself fulfills the first two requirements:
AXFRa form of “replication”For the second point about DNS zone transfer… it used to be the case that anyone could issue the
AXFRrequest to a DNS server. However, this basically dumps all the records on a DNS server’s zonefile for that domain. So, it’s often disallowed nowadays because it discloses all hosts in the zone file, some of which might be considered private by the domain owner. Instead, server admins usually configure this to only be allowed by trusted IP addresses of other hosts. (I guess it’s a very crude form of “web of trust” based on IP allow lists and the whims of a SysAdmin.)Maybe the Fediverse has use for piggybacking on DNS via TXT records for some use cases. However, it’s likely that some other decentralized method of replication might be invented specifically for federation with other ActivityPub servers.