Doing so requires protecting /metrics from direct access when proxied
through nginx. If camo is placed on a separate host, the equivalent
/metrics URL may need to be protected.
See https://github.com/cactus/go-camo#metrics for details on the
statistics so reported. Note that 5xx responses are _expected_ from
go-camo's statistics, as it returns 502 status code when the remote
server responds with 500/502/503/504, or 504 when the remote host
times out.
Because Camo includes logic to deny access to private subnets, routing
its requests through Smokescreen is generally not necessary. However,
it may be necessary if Zulip has configured a non-Smokescreen exit
proxy.
Default Camo to using the proxy only if it is not Smokescreen, with a
new `proxy.enable_for_camo` setting to override this behaviour if need
be. Note that that setting is in `zulip.conf` on the host with Camo
installed -- not the Zulip frontend host, if they are different.
Fixes: #20550.
For `no_serve_uploads`, `http_only`, which previously specified
"non-empty" to enable, this tightens what values are true. For
`pgroonga` and `queue_workers_multiprocess`, this broadens the
possible values from `enabled`, and `true` respectively.
Restarting the uwsgi processes by way of supervisor opens a window
during which nginx 502's all responses. uwsgi has a configuration
called "chain reloading" which allows for rolling restart of the uwsgi
processes, such that only one process at once in unavailable; see
uwsgi documentation ([1]).
The tradeoff is that this requires that the uwsgi processes load the
libraries after forking, rather than before ("lazy apps"); in theory
this can lead to larger memory footprints, since they are not shared.
In practice, as Django defers much of the loading, this is not as much
of an issue. In a very basic test of memory consumption (measured by
total memory - free - caches - buffers; 6 uwsgi workers), both
immediately after restarting Django, and after requesting `/` 60 times
with 6 concurrent requests:
| Non-lazy | Lazy app | Difference
------------------+------------+------------+-------------
Fresh | 2,827,216 | 2,870,480 | +43,264
After 60 requests | 3,332,284 | 3,409,608 | +77,324
..................|............|............|.............
Difference | +505,068 | +539,128 | +34,060
That is, "lazy app" loading increased the footprint pre-requests by
43MB, and after 60 requests grew the memory footprint by 539MB, as
opposed to non-lazy loading, which grew it by 505MB. Using wsgi "lazy
app" loading does increase the memory footprint, but not by a large
percentage.
The other effect is that processes may be served by either old or new
code during the restart window. This may cause transient failures
when new frontend code talks to old backend code.
Enable chain-reloading during graceful, puppetless restarts, but only
if enabled via a zulip.conf configuration flag.
Fixes#2559.
[1]: https://uwsgi-docs.readthedocs.io/en/latest/articles/TheArtOfGracefulReloading.html#chain-reloading-lazy-apps
Fix another tidy error caused by 1e4e6a09af23; as also noted in
f9a39b6703, these resources are necessary such that tidy does not
cleanup of smokescreen, and then force a recompilation of it again.
1e4e6a09af removed the resources for the unpacked directory, on the
argument that they were unnecessary. However, the directory (or file,
see below) that is unpacked must be managed, or it will be tidied on
the next puppet apply.
Add back the resource for `$dir`, but mark it `ensure => present`, to
support tarballs which only unpack to a single file (e.g. wal-g).
The homedir of a user cannot be changed if any processes are running
as them, so having it change over time as upgrades happen will break
puppet application, as the old grafana process under supervisor will
effectively lock changes to the user's homedir.
Unfortunately, that means that this change will thus fail to
puppet-apply unless `supervisorctl stop grafana` is run first, but
there's no way around that.
In the event that extracting doesn't produce the binary we expected it
to, all this will do is create an _empty_ file where we expect the
binary to be. This will likely muddle debugging.
Since the only reason the resourfce was made in the first place was to
make dependencies clear, switch to depending on the External_Dep
itself, when such a dependency is needed.
ab130ceb35 added a dependency on scripts.lib.zulip_tools; however,
check_postgresql_replication_lag is run on hosts which do not have a
zulip tree installed.
Inline the simple functions that were imported.
It should not use the configured zulip username, but should instead
pull from the login user (likely `nagios`), or an explicit alternate
provided PostgreSQL username. Failure to do so results in Nagios
failures because the `nagios` login does not have permissions to
authenticated the `zulip` PostgreSQL user.
This requires CI changes, as the install tests install as the `zulip`
login username, which allowed Nagios tests to pass previously; with
the custom database and username, however, they must be passed to
process_fts_updates explicitly when validating the install.
The Redis configuration, and the systemd file for it, assumes there
will be a pid file written to `/var/run/redis/redis.pid`, but
`/var/run/redis` is not created during installation.
Create `/run/redis`; as `/var/run` is a symlink to `/run` on systemd
systems, this is equivalent to `/var/run/redis`.
The systemd config file installed by the `memcached` package assumes
there will be a PID written to `/run/memcached/memcached.pid`. Since we
override `memcached.conf`, we have omitted the line that writes out the
PID to this file.
Systemd is smart enough to not _need_ the PID file to start up the
service correctly, but match the configuration. We create the
directory since the package does not do so. It is created as
`/run/memcached` and not `/var/run/memcached` because `/var/run` is a
symlink to `/run`.
The certbot package installs its own systemd timer (and cron job,
which disabled itself if systemd is enabled) which updates
certificates. This process races with the cron job which Zulip
installs -- the only difference being that Zulip respects the
`certbot.auto_renew` setting, and that it passes the deploy hook.
This means that occasionally nginx would not be reloaded, when the
systemd timer caught the expiration first.
Remove the custom cron job and `certbot-maybe-renew` script, and
reconfigure certbot to always reload nginx after deploying, using
certbot directory hooks.
Since `certbot.auto_renew` can't have an effect, remove the setting.
In turn, this removes the need for `--no-zulip-conf` to
`setup-certbot`. `--deploy-hook` is similarly removed, as running
deploy hooks to restart nginx is now the default; pass
`--no-directory-hooks` in standalone mode to not attempt to reload
nginx. The other property of `--deploy-hook`, of skipping symlinking
into place, is given its own flog.
PostgreSQL 11 and below used a configuration file names
`recovery.conf` to manage replicas and standbys; support for this was
removed in PostgreSQL 12[1], and the configuration parameters were
moved into the main `postgresql.conf`.
Add `zulip.conf` settings for the primary server hostname and
replication username, so that the complete `postgresql.conf`
configuration on PostgreSQL 14 can continue to be managed, even when
replication is enabled. For consistency, also begin writing out the
`recovery.conf` for PostgreSQL 11 and below.
In PostgreSQL 12 configuration and later, the `wal_level =
hot_standby` setting is removed, as `hot_standby` is equivalent to
`replica`, which is the default value[2]. Similarly, the
`hot_standby = on` setting is also the default[3].
Documentation is added for these features, and the commentary on the
"Export and Import" page referencing files under `puppet/zulip_ops/`
is removed, as those files no longer have any replication-specific
configuration.
[1]: https://www.postgresql.org/docs/current/recovery-config.html
[2]: https://www.postgresql.org/docs/12/runtime-config-wal.html#GUC-WAL-LEVEL
[3]: https://www.postgresql.org/docs/12/runtime-config-replication.html#GUC-HOT-STANDBY
These are both unsupported by PostgreSQL itself, as well as by Zulip;
the removal of Ubuntu Xenial and Debian Stretch support in Zulip 3.0
removed the requirement for PostgreSQL 9.6, and the previous versions
date back yet farther.
Alex Vandiver
Anders Kaseorg