Adds a section for writing and style guidlines to the tutorial
for writing help center articles. Moves the sections on 'Voice'
and 'User interface' to be in the new section, and adds a section
on 'Keyboard shortcuts'.
The default value in uwsgi is 4k; receiving more than this amount from
nginx leads to a 502 response (though, happily, the backend uwsgi does not
terminate).
ab18dbfde5 originally increased it from the unstated uwsgi default
of 4096, to 8192; b1da797955 made it configurable, in order to allow
requests from clients with many cookies, without causing 502's[1].
nginx defaults to a limitation of 1k, with 4 additional 8k header
lines allowed[2]; any request larger than that returns a response of
`400 Request Header Or Cookie Too Large`. The largest header size
theoretically possible from nginx, by default, is thus 33k, though
that would require packing four separate headers to exactly 8k each.
Remove the gap between nginx's limit and uwsgi's, which could trigger
502s, by removing the uwsgi configurability, and setting a 64k size in
uwsgi (the max allowable), which is larger than nginx's default limit.
uWSGI's documentation of `buffer-size` ([3], [4]) also notes that "It
is a security measure too, so adapt to your app needs instead of
maxing it out." Python has no security issues with buffers of 64k,
and there is no appreciable memory footprint difference to having a
larger buffer available in uwsgi.
[1]: https://chat.zulip.org/#narrow/stream/31-production-help/topic/works.20in.20Edge.20not.20Chrome/near/719523
[2]: https://nginx.org/en/docs/http/ngx_http_core_module.html#client_header_buffer_size
[3]: https://uwsgi-docs.readthedocs.io/en/latest/ThingsToKnow.html
[4]: https://uwsgi-docs.readthedocs.io/en/latest/Options.html#buffer-size
The content in `zulip-config.md` was moved (in #22315) to
`change-zulip-config.file.md`. This removes the now out-of-date
reference to this macro in the documentation for writing
integrations and removes the file as it is no longer in use.
markdown-include is GPL licensed.
Also, rewrite it as a block processor, so that it works correctly
inside indented blocks.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Since python-debian is GPL licensed, our script that imports it should
arguably be GPL licensed as well.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Backups are written every 16k of WAL archive, and by default do not
have an upper limit on how out of date they are, as `archive_timeout`
defaults to 0.
Also emphasize that these are streaming backups, not just one
point-in-time backup daily.
Fixes#21976.
Notable changes:
- Describe `X-Forwarded-For` by name.
- Switch each specific proxy to numbered steps.
- Link back to the `X-Forwarded-For` section in each proxy
- Default to using HTTPS, not HTTP, for the backend.
- Include the HTTP-to-HTTPS redirect code for all proxies; it is
important that it happen at the proxy, as the backend is unaware of
it.
- Call out Apache2 modules which are necessary.
- Specify where the dhparam.pem file can be found.
- Call out the `Host:` header forwarding necessary, and document
`USE_X_FORWARDED_HOST` if that is not possible.
- Standardize on 20 minutes of connection timeout.
Our current EC2 systems don’t have an interface named ‘eth0’, and if
they did, this script would do nothing but crash with ImportError
because we have never installed boto.utils for Python 3.
(The message of commit 2a4d851a7c made
an effort to document for future researchers why this script should
not have been blindly converted to Python 3. However, commit
2dc6d09c2a (#14278) was evidently
unresearched and untested.)
Signed-off-by: Anders Kaseorg <anders@zulip.com>
As a consequence:
• Bump minimum supported Python version to 3.8.
• Move Vagrant environment to Ubuntu 20.04, which has Python 3.8.
• Move CI frontend tests to Ubuntu 20.04.
• Move production build test to Ubuntu 20.04.
• Move 3.4 upgrade test to Ubuntu 20.04.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
Zulip Server 3.0 is now about 21 months old, which is more than
18 months. Per the general policy in the "Client apps" section
below, that means it's time to drop support for older versions.
We released 4.0 in 2021-05, so around 2022-11 we can update this
further to say 4.0.
One of the links in the GSoC ideas section in docs/gsoc.md led to
a page with 0 results. This has now been replaced with the correct
link leading to a list of issues with the mentioned labels.
On the Debian 10 -> 11 upgrade, the server is running Zulip 4.x, which
lets us pass `--audit-fts-indexes` to `upgrade-zulip-stage-2` rather
than run the command as a separate step.
The reindex-textual-data tool needs the venv to be cable to run;
switch the order of the last two steps, making them now match the
Debian 9 -> 10 and 10 -> upgrades.
Ref #21296.
When the credentials are provided by dint of being run on an EC2
instance with an assigned Role, we must be able to fetch the instance
metadata from IMDS -- which is precisely the type of internal-IP
request that Smokescreen denies.
While botocore supports a `proxies` argument to the `Config` object,
this is not actually respected when making the IMDS queries; only the
environment variables are read from. See
https://github.com/boto/botocore/issues/2644
As such, implement S3_SKIP_PROXY by monkey-patching the
`botocore.utils.should_bypass_proxies` function, to allow requests to
IMDS to be made without Smokescreen impeding them.
Fixes#20715.
This revised globe icon avoids looking like a "language choice" icon
(as the previous one did), while still being recognizably Earth (and
not a disk with some things drawn on it) and not showing only North
America (a flaw with the Font Awesome 4.7 icon).
Used a derivative of icon from
https://unpkg.com/ionicons@5.5.2/dist/svg/earth.svg
with modified outline by Vlad Korobov.
Previously, it was possible to configure `wal-g` backups without
replication enabled; this resulted in only daily backups, not
streaming backups. It was also possible to enable replication without
configuring the `wal-g` backups bucket; this simply failed to work.
Make `wal-g` backups always streaming, and warn loudly if replication
is enabled but `wal-g` is not configured.
Ubuntu 22.04 pushed a post-feature-freeze update to Python 3.10,
breaking virtual environments in a Debian patch
(https://bugs.launchpad.net/ubuntu/+source/python3.10/+bug/1962791).
Also, our antique version of Tornado doesn’t work in 3.10, and we’ll
need to do some work to upgrade that.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This reverts commit b7561049b765946d612069b52330695e8489bc7f.
The bug it worked around was fixed with the previous commit’s
upgrade.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This uses the myst_heading_anchors option to automatically generate
header anchors and make Sphinx aware of them. See
https://myst-parser.readthedocs.io/en/latest/syntax/optional.html#auto-generated-header-anchors.
Note: to be compatible with GitHub, MyST-Parser uses a slightly
different convention for .md fragment links than .html fragment links
when punctuation is involved. This does not affect the generated
fragment links in the HTML output.
Fixes#13264.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
We previously had a convention of redundantly including the directory
in relative links to reduce mistakes when moving content from one file
to another. However, these days we have a broken link checker in
test-documentation, and after #21237, MyST-Parser will check relative
links (including fragments) when you run build-docs.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
This was only used for upgrading from Zulip < 1.9.0, which is no
longer possible because Zulip < 2.1.0 had no common supported
platforms with current main.
If we ever want this optimization for a future migration, it would be
better implemented using Django merge migrations.
Signed-off-by: Anders Kaseorg <anders@zulip.com>
It seems like orange is the loudest possible color to
denote a quasi-neutral-idle state, so we hope to
replace it with another color.
This commit does not change any styling.
I removed the sentences in the doc, since they are
kind of too vague to be useful. If we want to say that
the idle state is correlated with the half-orange
circles in the buddy list, then we want to say that
more specifically.
The node test was slightly inaccurate.
I added `# etc.` to try to make it clear that
these are just examples.
I removed the puppeteer example, so that we
don't lie about "run in just a few seconds".
Renames `/docs/documentation/user.md` to reflect the rebranding
from "user documentation" to "help center documentation".
Also, fixes any linking in the docs to that file.
Updates the tutorial for writing help center articles to encourage
contributors to add to or enhance the existing help center docs
before writing a new articles for new features.
Also, generally updates references to 'user documentation' to be
'help center documentation'.
Additionally, updates some headers within the tutorials for clarity
and consistency, and adds some linkifying throughout the section on
writing documentation.
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
Zulip writes a `rabbitmq.config` configuration file which locks down
RabbitMQ to listen only on localhost:5672, as well as the RabbitMQ
distribution port, on localhost:25672.
The "distribution port" is part of Erlang's clustering configuration;
while it is documented that the protocol is fundamentally
insecure ([1], [2]) and can result in remote arbitrary execution of
code, by default the RabbitMQ configuration on Debian and Ubuntu
leaves it publicly accessible, with weak credentials.
The configuration file that Zulip writes, while effective, is only
written _after_ the package has been installed and the service
started, which leaves the port exposed until RabbitMQ or system
restart.
Ensure that rabbitmq's `/etc/rabbitmq/rabbitmq.config` is written
before rabbitmq is installed or starts, and that changes to that file
trigger a restart of the service, such that the ports are only ever
bound to localhost. This does not mitigate existing installs, since
it does not force a rabbitmq restart.
[1] https://www.erlang.org/doc/apps/erts/erl_dist_protocol.html
[2] https://www.erlang.org/doc/reference_manual/distributed.html#distributed-erlang-system
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.
The Erlang `epmd` daemon listens on port 4369, and provides
information (without authentication) about which Erlang processes are
listening on what ports. This information is not itself a
vulnerability, but may provide information for remote attackers about
what local Erlang services (such as `rabbitmq-server`) are running,
and where.
`epmd` supports an `ERL_EPMD_ADDRESS` environment variable to limit
which interfaces it binds on. While this environment variable is set
in `/etc/default/rabbitmq-server`, Zulip unfortunately attempts to
start `epmd` using an explicit `exec` block, which ignores those
settings.
Regardless, this lack of `ERL_EPMD_ADDRESS` variable only controls
`epmd`'s startup upon first installation. Upon reboot, there are two
ways in which `epmd` might be started, neither of which respect
`ERL_EPMD_ADDRESS`:
- On Focal, an `epmd` service exists and is activated, which uses
systemd's configuration to choose which interfaces to bind on, and
thus `ERL_EPMD_ADDRESS` is irrelevant.
- On Bionic (and Focal, due to a broken dependency from
`rabbitmq-server` to `epmd@` instead of `epmd`, which may lead to
the explicit `epmd` service losing a race), `epmd` is started by
`rabbitmq-server` when it does not detect a running instance.
Unfortunately, only `/etc/init.d/rabbitmq-server` would respects
`/etc/default/rabbitmq-server` -- and it defers the actual startup
to using systemd, which does not pass the environment variable
down. Thus, `ERL_EPMD_ADDRESS` is also irrelevant here.
We unfortunately cannot limit `epmd` to only listening on localhost,
due to a number of overlapping bugs and limitations:
- Manually starting `epmd` with `-address 127.0.0.1` silently fails
to start on hosts with IPv6 disabled, due to an Erlang bug ([1],
[2]).
- The dependencies of the systemd `rabbitmq-server` service can be
fixed to include the `epmd` service, and systemd can be made to
bind to `127.0.0.1:4369` and pass that socket to `epmd`, bypassing
the above bug. However, the startup of this service is not
guaranteed, because it races with other sources of `epmd` (see
below).
- Any process that runs `rabbitmqctl` results in `epmd` being started
if one is not currently running; these instances do not respect any
environment variables as to which addresses to bind on. This is
also triggered by `service rabbitmq-server status`, as well as
various Zulip cron jobs which inspect the rabbitmq queues. As
such, it is difficult-to-impossible to ensure that some other
`epmd` process will not win the race and open the port on all
interfaces.
Since the only known exposure from leaving port 4369 open is
information that rabbitmq is running on the host, and the complexity
of adjusting this to only bind on localhost is high, we remove the
setting which does not address the problem, and document that the port
is left open, and should be protected via system-level or
network-level firewalls.
[1]: https://bugs.launchpad.net/ubuntu/+source/erlang/+bug/1374109
[2]: https://github.com/erlang/otp/issues/4820
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>
With tweaks to security-model.md by tabbott to expand the SSO acronym.
Ignored, but still needs discussion on whether we should exclude this
rule:
```
The word ‘install’ is not a noun.
✗ ...ble to connect to the client during the install process: So you'll need to shut down a...
^^^^^^^
✓ ...ble to connect to the client during the installation process: So you'll need to shut down a...
A_INSTALL: a/the + install
The word ‘install’ is not a noun.
✗ ...detected at install time will cause the install to abort. If you already have PostgreSQ...
^^^^^^^
✓ ...detected at install time will cause the installation to abort. If you already have PostgreSQ...
A_INSTALL: a/the + install
```
This page contains a lot of other material related to GSoC than
just project ideas.
We would also want to add a redirect from the old URL to the new
one from the RTD admin page.
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