Provide more info why we don't have any thumbnails to serve (#13038)

Fix https://github.com/matrix-org/synapse/issues/13016

## New error code and status

### Before

Previously, we returned a `404` for `/thumbnail` which isn't even in the spec.

```json
{
  "errcode": "M_NOT_FOUND",
  "error": "Not found [b'hs1', b'tefQeZhmVxoiBfuFQUKRzJxc']"
}
```

### After

What does the spec say?

> 400: The request does not make sense to the server, or the server cannot thumbnail the content. For example, the client requested non-integer dimensions or asked for negatively-sized images.
>
> *-- https://spec.matrix.org/v1.1/client-server-api/#get_matrixmediav3thumbnailservernamemediaid*

Now with this PR, we respond with a `400` when we don't have thumbnails to serve and we explain why we might not have any thumbnails.

```json
{
    "errcode": "M_UNKNOWN",
    "error": "Cannot find any thumbnails for the requested media ([b'example.com', b'12345']). This might mean the media is not a supported_media_format=(image/jpeg, image/jpg, image/webp, image/gif, image/png) or that thumbnailing failed for some other reason. (Dynamic thumbnails are disabled on this server.)",
}
```

> Cannot find any thumbnails for the requested media ([b'example.com', b'12345']). This might mean the media is not a supported_media_format=(image/jpeg, image/jpg, image/webp, image/gif, image/png) or that thumbnailing failed for some other reason. (Dynamic thumbnails are disabled on this server.)


---

We still respond with a 404 in many other places. But we can iterate on those later and maybe keep some in some specific places after spec updates/clarification: https://github.com/matrix-org/matrix-spec/issues/1122

We can also iterate on the bugs where Synapse doesn't thumbnail when it should in other issues/PRs.
pull/13300/head
Eric Eastwood 2022-07-15 11:42:21 -05:00 committed by GitHub
parent e9ce4d089b
commit 7b67e93d49
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4 changed files with 129 additions and 17 deletions

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@ -0,0 +1 @@
Provide more info why we don't have any thumbnails to serve.

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@ -42,6 +42,18 @@ THUMBNAIL_SIZE_YAML = """\
# method: %(method)s
"""
# A map from the given media type to the type of thumbnail we should generate
# for it.
THUMBNAIL_SUPPORTED_MEDIA_FORMAT_MAP = {
"image/jpeg": "jpeg",
"image/jpg": "jpeg",
"image/webp": "jpeg",
# Thumbnails can only be jpeg or png. We choose png thumbnails for gif
# because it can have transparency.
"image/gif": "png",
"image/png": "png",
}
HTTP_PROXY_SET_WARNING = """\
The Synapse config url_preview_ip_range_blacklist will be ignored as an HTTP(s) proxy is configured."""
@ -79,13 +91,22 @@ def parse_thumbnail_requirements(
width = size["width"]
height = size["height"]
method = size["method"]
jpeg_thumbnail = ThumbnailRequirement(width, height, method, "image/jpeg")
png_thumbnail = ThumbnailRequirement(width, height, method, "image/png")
requirements.setdefault("image/jpeg", []).append(jpeg_thumbnail)
requirements.setdefault("image/jpg", []).append(jpeg_thumbnail)
requirements.setdefault("image/webp", []).append(jpeg_thumbnail)
requirements.setdefault("image/gif", []).append(png_thumbnail)
requirements.setdefault("image/png", []).append(png_thumbnail)
for format, thumbnail_format in THUMBNAIL_SUPPORTED_MEDIA_FORMAT_MAP.items():
requirement = requirements.setdefault(format, [])
if thumbnail_format == "jpeg":
requirement.append(
ThumbnailRequirement(width, height, method, "image/jpeg")
)
elif thumbnail_format == "png":
requirement.append(
ThumbnailRequirement(width, height, method, "image/png")
)
else:
raise Exception(
"Unknown thumbnail mapping from %s to %s. This is a Synapse problem, please report!"
% (format, thumbnail_format)
)
return {
media_type: tuple(thumbnails) for media_type, thumbnails in requirements.items()
}

View File

@ -17,9 +17,11 @@
import logging
from typing import TYPE_CHECKING, Any, Dict, List, Optional, Tuple
from synapse.api.errors import SynapseError
from synapse.api.errors import Codes, SynapseError, cs_error
from synapse.config.repository import THUMBNAIL_SUPPORTED_MEDIA_FORMAT_MAP
from synapse.http.server import (
DirectServeJsonResource,
respond_with_json,
set_corp_headers,
set_cors_headers,
)
@ -309,6 +311,19 @@ class ThumbnailResource(DirectServeJsonResource):
url_cache: True if this is from a URL cache.
server_name: The server name, if this is a remote thumbnail.
"""
logger.debug(
"_select_and_respond_with_thumbnail: media_id=%s desired=%sx%s (%s) thumbnail_infos=%s",
media_id,
desired_width,
desired_height,
desired_method,
thumbnail_infos,
)
# If `dynamic_thumbnails` is enabled, we expect Synapse to go down a
# different code path to handle it.
assert not self.dynamic_thumbnails
if thumbnail_infos:
file_info = self._select_thumbnail(
desired_width,
@ -384,8 +399,29 @@ class ThumbnailResource(DirectServeJsonResource):
file_info.thumbnail.length,
)
else:
# This might be because:
# 1. We can't create thumbnails for the given media (corrupted or
# unsupported file type), or
# 2. The thumbnailing process never ran or errored out initially
# when the media was first uploaded (these bugs should be
# reported and fixed).
# Note that we don't attempt to generate a thumbnail now because
# `dynamic_thumbnails` is disabled.
logger.info("Failed to find any generated thumbnails")
respond_404(request)
respond_with_json(
request,
400,
cs_error(
"Cannot find any thumbnails for the requested media (%r). This might mean the media is not a supported_media_format=(%s) or that thumbnailing failed for some other reason. (Dynamic thumbnails are disabled on this server.)"
% (
request.postpath,
", ".join(THUMBNAIL_SUPPORTED_MEDIA_FORMAT_MAP.keys()),
),
code=Codes.UNKNOWN,
),
send_cors=True,
)
def _select_thumbnail(
self,

View File

@ -126,7 +126,9 @@ class _TestImage:
expected_scaled: The expected bytes from scaled thumbnailing, or None if
test should just check for a valid image returned.
expected_found: True if the file should exist on the server, or False if
a 404 is expected.
a 404/400 is expected.
unable_to_thumbnail: True if we expect the thumbnailing to fail (400), or
False if the thumbnailing should succeed or a normal 404 is expected.
"""
data: bytes
@ -135,6 +137,7 @@ class _TestImage:
expected_cropped: Optional[bytes] = None
expected_scaled: Optional[bytes] = None
expected_found: bool = True
unable_to_thumbnail: bool = False
@parameterized_class(
@ -192,6 +195,7 @@ class _TestImage:
b"image/gif",
b".gif",
expected_found=False,
unable_to_thumbnail=True,
),
),
],
@ -366,18 +370,29 @@ class MediaRepoTests(unittest.HomeserverTestCase):
def test_thumbnail_crop(self) -> None:
"""Test that a cropped remote thumbnail is available."""
self._test_thumbnail(
"crop", self.test_image.expected_cropped, self.test_image.expected_found
"crop",
self.test_image.expected_cropped,
expected_found=self.test_image.expected_found,
unable_to_thumbnail=self.test_image.unable_to_thumbnail,
)
def test_thumbnail_scale(self) -> None:
"""Test that a scaled remote thumbnail is available."""
self._test_thumbnail(
"scale", self.test_image.expected_scaled, self.test_image.expected_found
"scale",
self.test_image.expected_scaled,
expected_found=self.test_image.expected_found,
unable_to_thumbnail=self.test_image.unable_to_thumbnail,
)
def test_invalid_type(self) -> None:
"""An invalid thumbnail type is never available."""
self._test_thumbnail("invalid", None, False)
self._test_thumbnail(
"invalid",
None,
expected_found=False,
unable_to_thumbnail=self.test_image.unable_to_thumbnail,
)
@unittest.override_config(
{"thumbnail_sizes": [{"width": 32, "height": 32, "method": "scale"}]}
@ -386,7 +401,12 @@ class MediaRepoTests(unittest.HomeserverTestCase):
"""
Override the config to generate only scaled thumbnails, but request a cropped one.
"""
self._test_thumbnail("crop", None, False)
self._test_thumbnail(
"crop",
None,
expected_found=False,
unable_to_thumbnail=self.test_image.unable_to_thumbnail,
)
@unittest.override_config(
{"thumbnail_sizes": [{"width": 32, "height": 32, "method": "crop"}]}
@ -395,14 +415,22 @@ class MediaRepoTests(unittest.HomeserverTestCase):
"""
Override the config to generate only cropped thumbnails, but request a scaled one.
"""
self._test_thumbnail("scale", None, False)
self._test_thumbnail(
"scale",
None,
expected_found=False,
unable_to_thumbnail=self.test_image.unable_to_thumbnail,
)
def test_thumbnail_repeated_thumbnail(self) -> None:
"""Test that fetching the same thumbnail works, and deleting the on disk
thumbnail regenerates it.
"""
self._test_thumbnail(
"scale", self.test_image.expected_scaled, self.test_image.expected_found
"scale",
self.test_image.expected_scaled,
expected_found=self.test_image.expected_found,
unable_to_thumbnail=self.test_image.unable_to_thumbnail,
)
if not self.test_image.expected_found:
@ -459,8 +487,24 @@ class MediaRepoTests(unittest.HomeserverTestCase):
)
def _test_thumbnail(
self, method: str, expected_body: Optional[bytes], expected_found: bool
self,
method: str,
expected_body: Optional[bytes],
expected_found: bool,
unable_to_thumbnail: bool = False,
) -> None:
"""Test the given thumbnailing method works as expected.
Args:
method: The thumbnailing method to use (crop, scale).
expected_body: The expected bytes from thumbnailing, or None if
test should just check for a valid image.
expected_found: True if the file should exist on the server, or False if
a 404/400 is expected.
unable_to_thumbnail: True if we expect the thumbnailing to fail (400), or
False if the thumbnailing should succeed or a normal 404 is expected.
"""
params = "?width=32&height=32&method=" + method
channel = make_request(
self.reactor,
@ -496,6 +540,16 @@ class MediaRepoTests(unittest.HomeserverTestCase):
else:
# ensure that the result is at least some valid image
Image.open(BytesIO(channel.result["body"]))
elif unable_to_thumbnail:
# A 400 with a JSON body.
self.assertEqual(channel.code, 400)
self.assertEqual(
channel.json_body,
{
"errcode": "M_UNKNOWN",
"error": "Cannot find any thumbnails for the requested media ([b'example.com', b'12345']). This might mean the media is not a supported_media_format=(image/jpeg, image/jpg, image/webp, image/gif, image/png) or that thumbnailing failed for some other reason. (Dynamic thumbnails are disabled on this server.)",
},
)
else:
# A 404 with a JSON body.
self.assertEqual(channel.code, 404)