These checks suffer from a couple notable problems:
- They are only enabled on staging hosts -- where they should never
be run. Since ef6d0ec5ca, these supervisor processes are only
run on one host, and never on the staging host.
- They run as the `nagios` user, which does not have appropriate
permissions, and thus the checks always fail. Specifically,
`nagios` does not have permissions to run `supervisorctl`, since
the socket is owned by the `zulip` user, and mode 0700; and the
`nagios` user does not have permission to access Zulip secrets to
run `./manage.py print_email_delivery_backlog`.
Rather than rewrite these checks to run on a cron as zulip, and check
those file contents as the nagios user, drop these checks -- they can
be rewritten at a later point, or replaced with Prometheus alerting,
and currently serve only to cause always-failing Nagios checks, which
normalizes alert failures.
Leave the files installed if they currently exist, rather than
cluttering puppet with `ensure => absent`; they do no harm if they are
left installed.
93f62b999e removed the last file in
puppet/zulip/files/nagios_plugins/zulip_nagios_server, which means the
singular rule in zulip::nagios no longer applies cleanly.
Remove the `zulip::nagios` class, as it is no longer needed.
An organization with at most 5 users that is behind on payments isn't
worth spending time on investigating the situation.
For larger organizations, we likely want somewhat different logic that
at least does not void invoices.
This is similar cleanup to 3ab9b31d2f, but only affects zulip_ops
services; it serves to ensure that any of these services which are no
longer enabled are automatically removed from supervisor.
Note that this will cause a supervisor restart on all affected hosts,
which will restart all supervisor services.
Failure to do this results in:
```
psql: error: failed to connect to `host=localhost user=zulip database=zulip`: failed to write startup message (x509: certificate is valid for [redacted], not localhost)
```
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.
Alex Vandiver
Anders Kaseorg
Vishnu KS
Tim Abbott