Host-based md5 auth for 127.0.0.1 must be removed from `pg_hba.conf`,
otherwise password authentication is preferred over certificate-based
authentication for localhost.
Nagios refuses to allow any modifications with use_authentication off;
re-enabled "authentication" but set a default user, which (by way of
the `*` permissions in 359f37389a) is allowed to take all actions.
This requires switching to a reverse tunnel for the auth connection,
with the side effect that the `zulip_ops::teleport::node` manifest can
be applied on servers anywhere in the Internet; they do not need to
have any publicly-available open ports.
This means that services will only open their ports if they are
actually run, without having to clutter rules.v4 with a log of `if`
statements.
This does not go as far as using `puppetlabs/firewall`[1] because that
would represent an additional DSL to learn; raw IPtables sections can
easily be inserted into the generated iptables file via
`concat::fragment` (either inline, or as a separate file), but config
can be centralized next to the appropriate service.
[1] https://forge.puppet.com/modules/puppetlabs/firewall
This moves the `.asc` files into subdirectories, and writes out the
according `.list` files into them. It moves from templates to
written-out `.list` files for clarity and ease of
implementation (Debian and Ubuntu need different templates for
`zulip`), and as a way of making explicit which releases are supported
for each list. For the special-case of the PGroonga signing key, we
source an additional file within the directory.
This simplifies the process for adding another class of `.list` file.
These thresholds are in relationship to the
`autovacuum_freeze_max_age`, *not* the XID wraparound, which happens
at 2^31-1. As such, it is *perfectly normal* that they hit 100%, and
then autovacuum kicks in and brings it back down. The unusual
condition is that PostgreSQL pushes past the point where an autovacuum
would be triggered -- therein lies the XID wraparound danger.
With the `autovacuum_freeze_max_age` set to 2000000000 in
`postgresql.conf`, XID wraparound happens at 107.3%. Set the warning
and error thresholds to below this, but above 100% so this does not
trigger constantly.
Matching the full process name (-x without -f) or full command
line (-xf) is less prone to mistakes like matching a random substring
of some other command line or pgrep matching itself.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This verifies that the proxy is working by accessing a
highly-available website through it. Since failure of this equates to
failures of Sentry notifications and Android mobile push
notifications, this is a paging service.
In production, the `wildcard-zulipchat.com.combined-chain.crt` file is
just a symlink to the snakeoil certificates; but we do not puppet that
symlink, which makes new hosts fail to start cleanly. Instead, point
explicitly to the snakeoil certificate, and explain why.
Redis is not nagios, and this only leads to confusion as to why there
is a nagios domain setting on frontend servers; it also leaves the
`redis0` part of the name buried in the template.
Switch to an explicit variable for the redis hostname.
This is more broadly useful than for just Kandra; provide
documentation and means to install Smokescreen for stand-alone
servers, and motivate its use somewhat more.
This is required for unattended upgrades to actually run regularly.
In some distributions, it may be found in 20auto-upgrades, but placing
it here makes it more discoverable.
Alex Vandiver
Anders Kaseorg
Tim Abbott