- Renames "Customize Zulip" to "Server configuration".
- Cross-links "Server configuration" with "System and deployment
configuration".
Fixes part of #23984.
The `postfix.mailname` setting in `/etc/zulip.conf` was previously
only used for incoming mail, to identify in Postfix configuration
which messages were "local."
Also set `/etc/mailname`, which is used by Postfix to set how it
identifies to other hosts when sending outgoing email.
Co-authored-by: Alex Vandiver <alexmv@zulip.com>
These files are not Jinja2 templates, so there's no reason that they needed
to be inside `templates/zerver`. Moving them to the top level reflects their
importance and also makes it feel nicer to work on editing the help center content,
without it being unnecessary buried deep in the codebase.
For descriptive endpoints, such as `/register`, that might raise
Schema Validation errors via `validate_against_openapi_schema`,
omits the OpenAPI schema definition in the error output.
Also omits the error instance definition in the error output
when it is a jsonschema object with over 100 properties. This
means that the test instance for objects, like user settings,
will be printed in the error output, but the test instance for
the entire endpoint will not be printed to the console.
The omitted output can be thousands of lines long making it
difficult to find the initial console output that actually helps
the contributor with debugging.
Adds a section in "Documenting REST API endpoints" about
debugging and understanding these errors that is linked to
in the error console output.
When file uploads are stored in S3, this means that Zulip serves as a
302 to S3. Because browsers do not cache redirects, this means that
no image contents can be cached -- and upon every page load or reload,
every recently-posted image must be re-fetched. This incurs extra
load on the Zulip server, as well as potentially excessive bandwidth
usage from S3, and on the client's connection.
Switch to fetching the content from S3 in nginx, and serving the
content from nginx. These have `Cache-control: private, immutable`
headers set on the response, allowing browsers to cache them locally.
Because nginx fetching from S3 can be slow, and requests for uploads
will generally be bunched around when a message containing them are
first posted, we instruct nginx to cache the contents locally. This
is safe because uploaded file contents are immutable; access control
is still mediated by Django. The nginx cache key is the URL without
query parameters, as those parameters include a time-limited signed
authentication parameter which lets nginx fetch the non-public file.
This adds a number of nginx-level configuration parameters to control
the caching which nginx performs, including the amount of in-memory
index for he cache, the maximum storage of the cache on disk, and how
long data is retained in the cache. The currently-chosen figures are
reasonable for small to medium deployments.
The most notable effect of this change is in allowing browsers to
cache uploaded image content; however, while there will be many fewer
requests, it also has an improvement on request latency. The
following tests were done with a non-AWS client in SFO, a server and
S3 storage in us-east-1, and with 100 requests after 10 requests of
warm-up (to fill the nginx cache). The mean and standard deviation
are shown.
| | Redirect to S3 | Caching proxy, hot | Caching proxy, cold |
| ----------------- | ------------------- | ------------------- | ------------------- |
| Time in Django | 263.0 ms ± 28.3 ms | 258.0 ms ± 12.3 ms | 258.0 ms ± 12.3 ms |
| Small file (842b) | 586.1 ms ± 21.1 ms | 266.1 ms ± 67.4 ms | 288.6 ms ± 17.7 ms |
| Large file (660k) | 959.6 ms ± 137.9 ms | 609.5 ms ± 13.0 ms | 648.1 ms ± 43.2 ms |
The hot-cache performance is faster for both large and small files,
since it saves the client the time having to make a second request to
a separate host. This performance improvement remains at least 100ms
even if the client is on the same coast as the server.
Cold nginx caches are only slightly slower than hot caches, because
VPC access to S3 endpoints is extremely fast (assuming it is in the
same region as the host), and nginx can pool connections to S3 and
reuse them.
However, all of the 648ms taken to serve a cold-cache large file is
occupied in nginx, as opposed to the only 263ms which was spent in
nginx when using redirects to S3. This means that to overall spend
less time responding to uploaded-file requests in nginx, clients will
need to find files in their local cache, and skip making an
uploaded-file request, at least 60% of the time. Modeling shows a
reduction in the number of client requests by about 70% - 80%.
The `Content-Disposition` header logic can now also be entirely shared
with the local-file codepath, as can the `url_only` path used by
mobile clients. While we could provide the direct-to-S3 temporary
signed URL to mobile clients, we choose to provide the
served-from-Zulip signed URL, to better control caching headers on it,
and greater consistency. In doing so, we adjust the salt used for the
URL; since these URLs are only valid for 60s, the effect of this salt
change is minimal.
Moving `/user_avatars/` to being served partially through Django
removes the need for the `no_serve_uploads` nginx reconfiguring when
switching between S3 and local backends. This is important because a
subsequent commit will move S3 attachments to being served through
nginx, which would make `no_serve_uploads` entirely nonsensical of a
name.
Serve the files through Django, with an offload for the actual image
response to an internal nginx route. In development, serve the files
directly in Django.
We do _not_ mark the contents as immutable for caching purposes, since
the path for avatar images is hashed only by their user-id and a salt,
and as such are reused when a user's avatar is updated.
The authenticate_by_username limit of 5 attempts per 30 minutes can get
annoying in some cases where the user really forgot their password and
should be allowed to keep trying with admin approvial - so we should
document the command that allows unblocking them.
Changes all the uses of the word "operators" to "filters" in
contributor docs, help center, and landing page to align with
the updated help center documentation.
Moves files in `templates/zerver/help/include` that are used
specifically for API documentation pages to be in a new directory:
`templates/zerver/api/include`.
Adds a boolean parameter to `render_markdown_path` to be used
for help center documentation articles.
Also moves the test file `empty.md` to the new directory since
this is the default directory for these special include macros
that are used in documentation pages.
Moves files in `templates/zerver/help/include` that are used
specifically for integrations documentation to be in a new
directory: `templates/zerver/integrations/include`.
Adds a boolean parameter to `render_markdown_path` to be used
for integrations documentation pages.
The documentation included the full policy for the file uploads
bucket, but only one additional statement for the avatars bucket; the
reader needed to assemble the full policy themselves.
Switch to explicitly providing the full policy for both.
Fixes#23110.
Alex Vandiver
Dhruv Gupta
David Rosa
Tran Sang
Lauryn Menard
Sahil Batra
Alya Abbott
Lauryn Menard
Anders Kaseorg
khadeom
Mateusz Mandera
Josh Klar
Tim Abbott