Comment 6 for bug 1622613

Update as to why the bootstrap of Galera cluster was failing:

We found out with Mike Bayer that version 25.3.12 of the galera WSREP provider behaves differently than version 25.3.5 when processing the provider option:

   wsrep_provider_options = gmcast.listen_addr=tcp://[172.16.2.15]:4567

This value is being set by t-h-t and has square brackets in the address to tell galera to listen to either an IPv4 or IPv6 address at startup.

In newer version of the galera provider, joining nodes won't connect to the cluster if the listen address is an IPv4 and contains brackets.

Removing brackets makes the bootstrap work again for IPv4 use cases.
Checks for IPv6 would need to be done to check whether brackets are still working as expected.