The RabbitMQ docs state ([1]):
RabbitMQ nodes and CLI tools (e.g. rabbitmqctl) use a cookie to
determine whether they are allowed to communicate with each
other. [...] The cookie is just a string of alphanumeric
characters up to 255 characters in size. It is usually stored in a
local file.
...and goes on to state (emphasis ours):
If the file does not exist, Erlang VM will try to create one with
a randomly generated value when the RabbitMQ server starts
up. Using such generated cookie files are **appropriate in
development environments only.**
The auto-generated cookie does not use cryptographic sources of
randomness, and generates 20 characters of `[A-Z]`. Because of a
semi-predictable seed, the entropy of this password is thus less than
the idealized 26^20 = 94 bits of entropy; in actuality, it is 36 bits
of entropy, or potentially as low as 20 if the performance of the
server is known.
These sizes are well within the scope of remote brute-force attacks.
On provision, install, and upgrade, replace the default insecure
20-character Erlang cookie with a cryptographically secure
255-character string (the max length allowed).
[1] https://www.rabbitmq.com/clustering.html#erlang-cookie
5c450afd2d, in ancient history, switched from `check_call` to
`check_output` and throwing away its result.
Use check_call, so that we show the steps to (re)starting the server.
This is required in order to lock down the RabbitMQ port to only
listen on localhost. If the nodename is `rabbit@hostname`, in most
circumstances the hostname will resolve to an external IP, which the
rabbitmq port will not be bound to.
Installs which used `rabbit@hostname`, due to RabbitMQ having been
installed before Zulip, would not have functioned if the host or
RabbitMQ service was restarted, as the localhost restrictions in the
RabbitMQ configuration would have made rabbitmqctl (and Zulip cron
jobs that call it) unable to find the rabbitmq server.
The previous commit ensures that configure-rabbitmq is re-run after
the nodename has changed. However, rabbitmq needs to be stopped
before `rabbitmq-env.conf` is changed; we use an `onlyif` on an `exec`
to print the warning about the node change, and let the subsequent
config change and notify of the service and configure-rabbitmq to
complete the re-configuration.
`/etc/rabbitmq/rabbitmq-env.conf` sets the nodename; anytime the
nodename changes, the backing database changes, and this requires
re-creating the rabbitmq users and permissions.
Trigger this in puppet by running configure-rabbitmq after the file
changes.
This reverts commit 889547ff5e. It is
unused in the Docker container, as the configurtaion of the `zulip`
user in the rabbitmq node is done via environment variables. The
Zulip host in that context does not have `rabbitmqctl` installed, and
would have needed to know the Erlang cookie to be able to run these
commands.
This addresses the problems mentioned in the previous commit, but for
existing installations which have `authenticator = standalone` in
their configurations.
This reconfigures all hostnames in certbot to use the webroot
authenticator, and attempts to force-renew their certificates.
Force-renewal is necessary because certbot contains no way to merely
update the configuration. Let's Encrypt allows for multiple extra
renewals per week, so this is a reasonable cost.
Because the certbot configuration is `configobj`, and not
`configparser`, we have no way to easily parse to determine if webroot
is in use; additionally, `certbot certificates` does not provide this
information. We use `grep`, on the assumption that this will catch
nearly all cases.
It is possible that this will find `authenticator = standalone`
certificates which are managed by Certbot, but not Zulip certificates.
These certificates would also fail to renew while Zulip is running, so
switching them to use the Zulip webroot would still be an improvement.
Fixes#20593.
Installing certbot with --method=standalone means that the
configuration file will be written to assume that the standalone
method will be used going forward. Since nginx will be running,
attempts to renew the certificate will fail.
Install a temporary self-signed certificate, just to allow nginx to
start, and then follow up (after applying puppet to start nginx) with
the call to setup-certbot, which will use the webroot authenticator.
The `setup-certbot --method=standalone` option is left intact, for use
in development environments.
Fixes part of #20593; it does not address installs which were
previously improperly configured with `authenticator = standalone`.
As a consequence:
• Bump minimum supported Python version to 3.7.
• Move Vagrant environment to Debian 10, which has Python 3.7.
• Move CI frontend tests to Debian 10.
• Move production build test to Debian 10.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This catches nine functional indexes that the previous query didn’t:
upper_preregistration_email_idx
upper_stream_name_idx
upper_subject_idx
upper_userprofile_email_idx
zerver_message_recipient_upper_subject
zerver_mutedtopic_stream_topic
zerver_stream_realm_id_name_uniq
zerver_userprofile_realm_id_delivery_email_uniq
zerver_userprofile_realm_id_email_uniq
Signed-off-by: Anders Kaseorg <anders@zulip.com>
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
On a system where ‘apt-get update’ has never been run, ‘apt-cache
policy’ may show no repositories at all. Try to correct this with
‘apt-get update’ before giving up.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
If nginx was already installed, and we're using the webroot method of
initializing certbot, nginx needs to be reloaded. Hooks in
`/etc/letsencrypt/renewal-hooks/deploy/` do not run during initial
`certbot certonly`, so an explicit reload is required.
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.
We've had a number of unhappy reports of upgrades failing due to
webpack requiring too much memory. While the previous commit will
likely fix this issue for everyone, it's worth improving the error
message for failures here.
We avoid doing the stop+retry ourselves, because that could cause an
outage in a production system if webpack fails for another reason.
Fixes#20105.
Since the upgrade to Webpack 5, we've been seeing occasional reports
that servers with roughly 4GiB of RAM were getting OOM kills while
running webpack.
Since we can't readily optimize the memory requirements for webpack
itself, we should raise the RAM requirements for doing the
lower-downtime upgrade strategy.
Fixes#20231.
Stopping both `zulip-tornado` and `zulip-tornado:*` causes errors on
deploys with tornado sharding, as the plain `zulip-tornado` service
does not exist.
Pass `zulip-tornado:*`, which matches both plain `zulip-tornado`, as
well as the sharded `zulip-tornado:zulip-tornado-port-9800` cases.
The `analyze_new_cluster.sh` script output by `pg_upgrade` just runs
`vacuumdb --all --analyze-in-stages`, which runs three passes over the
database, getting better stats each time. Each of these passes is
independent; the third pass does not require the first two.
`--analyze-in-stages` is only provided to get "something" into the
database, on the theory that it could then be started and used. Since
we wait for all three passes to complete before starting the database,
the first two passes add no value.
Additionally, PosttgreSQL 14 and up stop writing the
`analyze_new_cluster.sh` script as part of `pg_upgrade`, suggesting
the equivalent `vacuumdb --all --analyze-in-stages` call instead.
Switch to explicitly call `vacuumdb --all --analyze-only`, since we do
not gain any benefit from `--analyze-in-stages`. We also enable
parallelism, with `--jobs 10`, in order to analyze up to 10 tables in
parallel. This may increase load, but will accelerate the upgrade
process.
scripts.lib.node_cache expects Yarn to be in /srv/zulip-yarn, so if
it’s installed somewhere else, even if it’s the right version, we need
to reinstall it.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
It recently started failing on Debian 10 (buster). We immediately
follow this by replacing these packages with our own versions from
pip.txt, anyway.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
The support for bullseye was added in #17951
but it was not documented as bullseye was
frozen and did not have proper configuration
files, hence wasn't documented.
Since now bullseye is released as a stable
version, it's support can be documented.
Alex Vandiver
Anders Kaseorg
Tim Abbott
rht
Gaurav Pandey