Issues with repo sync from repo.almalinux.org

For three days (since May 16, 2023 02:34:23 +0200) all my syncs of almalinux repositories fail with errors like

Request timed out for https://repo.almalinux.org/almalinux/8/BaseOS/x86_64/os/repodata/repomd.xml. Increasing the total_timeout value on the remote might help.

The problems seems to be that the https connection on the IPv6 address isn’t working:

# host repo.almalinux.org
repo.almalinux.org has address 67.222.0.50
repo.almalinux.org has IPv6 address 2600:4c00:400::2
# curl -v 'https://repo.almalinux.org/almalinux/8/BaseOS/x86_64/os/repodata/repomd.xml'
*   Trying 2600:4c00:400::2...
* TCP_NODELAY set
*   Trying 67.222.0.50...
* TCP_NODELAY set
* Connected to repo.almalinux.org (67.222.0.50) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
...
# curl -6 -v 'https://repo.almalinux.org/almalinux/8/BaseOS/x86_64/os/repodata/repomd.xml'
*   Trying 2600:4c00:400::2...
* TCP_NODELAY set
* connect to 2600:4c00:400::2 port 443 failed: Connection timed out
* Failed to connect to repo.almalinux.org port 443: Connection timed out
* Closing connection 0
curl: (7) Failed to connect to repo.almalinux.org port 443: Connection timed out

Now while curl switches to IPv4 quickly, it seems pulp-rpm doesn’t, but sticks with IPv6 until it times out.

foreman-3.5.3-1.el8.noarch
katello-4.7.5-1.el8.noarch

I have sent a message to almalinux users mailing list and the ipv6 address issue on their end has been solved. Both IPs now properly connect again.

For the timeout issue with pulp I have opened IPv6/IPv4 failover · Issue #3862 · pulp/pulpcore · GitHub