TL;DR:
* Let's Encrypt [0] TLS certificates are "signed" by "root"
certificates to create a chain of trust
* The oldest "root" signing certificate for LE certs (DST Root CA X3)
expired on 2021-09-30 [1]
* Deprecated Toolforge Kubernetes containers only knew this root
certificate and not the newer root certificate (ISRG Root X1)
* Update your tool to a newer container to fix
We are starting to hear reports of tools that suddenly stopped working
on 2021-09-30. The common issue is accessing the APIs for Wikimedia
wikis.
The Wikimedia wikis use multiple TLS certificates issued by different
providers for redundancy and protection against a problem with a
single certificate provider. One of the certificate providers that we
use is Let's Encrypt (LE) [0]. LE certificates are themselves signed
by multiple "root" certificates to create a chain of trust that your
web browser or other TLS verifying software can trust. The oldest root
certificate (named "DST Root CA X3") used to sign the LE certificates
expired on 2021-09-30 [1]. Very old operating systems and some
compiled software do not have the newer root certificate (named "ISRG
Root X1") in their trusted certificate collection. These systems are
now rejecting LE certificates.
In Toolforge, we think that this mainly affects tools running on the
Kubernetes cluster inside Debian Jessie based containers. Specifically
the "php5.6", "python", "python2", and "ruby2"
containers are expected
to have issues with the LE certificate expiration based on what we
have found so far. Recommended replacement containers are "php7.4",
"python3.9", and "ruby25".
We also have reports of `mono` on the bastions + grid engine failing.
We do not yet have a fix for this. It will require us to compile and
install a newer version of mono for everyone who is using it.
Interested folks can follow progress of our infrastructure updates in
response to this issue at T291387 [3].
[0]:
https://letsencrypt.org/
[1]:
https://letsencrypt.org/docs/dst-root-ca-x3-expiration-september-2021/
[2]:
https://phabricator.wikimedia.org/T291387
Bryan
--
Bryan Davis Technical Engagement Wikimedia Foundation
Principal Software Engineer Boise, ID USA
[[m:User:BDavis_(WMF)]] irc: bd808