# Copyright (C) 2019-2023 The Software Heritage developers
# See the AUTHORS file at the top-level directory of this distribution
# License: GNU General Public License version 3, or any later version
# See top-level LICENSE file for more information
"""
A proxy HTTP server for swh-graph, talking to the Rust code via the gRPC API.
"""
import json
import logging
import os
from typing import Optional
import aiohttp.test_utils
import aiohttp.web
from google.protobuf import json_format
from google.protobuf.field_mask_pb2 import FieldMask
import grpc
from swh.core.config import read as config_read
from swh.graph.grpc.swhgraph_pb2 import (
GetNodeRequest,
NodeFilter,
StatsRequest,
TraversalRequest,
)
from swh.graph.grpc.swhgraph_pb2_grpc import TraversalServiceStub
from swh.graph.grpc_server import spawn_rust_grpc_server, stop_grpc_server
from swh.model.swhids import EXTENDED_SWHID_TYPES
try:
from contextlib import asynccontextmanager
except ImportError:
# Compatibility with 3.6 backport
from async_generator import asynccontextmanager # type: ignore
# maximum number of retries for random walks
RANDOM_RETRIES = 10 # TODO make this configurable via rpc-serve configuration
logger = logging.getLogger(__name__)
async def _aiorpcerror_middleware(app, handler):
async def middleware_handler(request):
try:
return await handler(request)
except grpc.aio.AioRpcError as e:
# The default error handler of the RPC framework tries to serialize this
# with msgpack; which for some unknown reason causes it to raise
# ValueError("recursion limit exceeded") with a lot of context, causing
# Sentry to be overflowed with gigabytes of logs (160KB per event, with
# potentially hundreds of thousands of events per day).
# Instead, we simply serialize the exception to a string.
# https://sentry.softwareheritage.org/share/issue/d6d4db971e4b47728a6c1dd06cb9b8a5/
raise aiohttp.web.HTTPServiceUnavailable(text=str(e))
return middleware_handler
[docs]
class GraphServerApp(aiohttp.web.Application):
def __init__(self, *args, middlewares=(), **kwargs):
middlewares = (_aiorpcerror_middleware,) + middlewares
super().__init__(*args, middlewares=middlewares, **kwargs)
self.on_startup.append(self._start)
self.on_shutdown.append(self._stop)
@staticmethod
async def _start(app):
app["channel"] = grpc.aio.insecure_channel(app["rpc_url"])
await app["channel"].__aenter__()
app["rpc_client"] = TraversalServiceStub(app["channel"])
await app["rpc_client"].Stats(StatsRequest(), wait_for_ready=True)
@staticmethod
async def _stop(app):
await app["channel"].__aexit__(None, None, None)
if app.get("local_server"):
stop_grpc_server(app["local_server"])
[docs]
async def index(request):
return aiohttp.web.Response(
content_type="text/html",
body="""<html>
<head><title>Software Heritage graph server</title></head>
<body>
<p>You have reached the <a href="https://www.softwareheritage.org/">
Software Heritage</a> graph API server.</p>
<p>See its
<a href="https://docs.softwareheritage.org/devel/swh-graph/api.html">API
documentation</a> for more information.</p>
</body>
</html>""",
)
[docs]
class GraphView(aiohttp.web.View):
"""Base class for views working on the graph, with utility functions"""
def __init__(self, *args, **kwargs):
super().__init__(*args, **kwargs)
self.rpc_client: TraversalServiceStub = self.request.app["rpc_client"]
[docs]
def get_direction(self):
"""Validate HTTP query parameter `direction`"""
s = self.request.query.get("direction", "forward")
if s not in ("forward", "backward"):
raise aiohttp.web.HTTPBadRequest(text=f"invalid direction: {s}")
return s.upper()
[docs]
def get_edges(self):
"""Validate HTTP query parameter `edges`, i.e., edge restrictions"""
s = self.request.query.get("edges", "*")
if any(
[
node_type != "*" and node_type not in EXTENDED_SWHID_TYPES
for edge in s.split(":")
for node_type in edge.split(",", maxsplit=1)
]
):
raise aiohttp.web.HTTPBadRequest(text=f"invalid edge restriction: {s}")
return s
[docs]
def get_return_types(self):
"""Validate HTTP query parameter 'return types', i.e,
a set of types which we will filter the query results with"""
s = self.request.query.get("return_types", "*")
if any(
node_type != "*" and node_type not in EXTENDED_SWHID_TYPES
for node_type in s.split(",")
):
raise aiohttp.web.HTTPBadRequest(
text=f"invalid type for filtering res: {s}"
)
# if the user puts a star,
# then we filter nothing, we don't need the other information
if "*" in s:
return "*"
else:
return s
[docs]
def get_max_matching_nodes(self):
"""Validate HTTP query parameter `max_matching_nodes`, i.e., number of results"""
s = self.request.query.get("max_matching_nodes", "0")
try:
return int(s)
except ValueError:
raise aiohttp.web.HTTPBadRequest(
text=f"invalid max_matching_nodes value: {s}"
)
[docs]
def get_max_edges(self):
"""Validate HTTP query parameter 'max_edges', i.e.,
the limit of the number of edges that can be visited"""
s = self.request.query.get("max_edges", "0")
try:
return int(s)
except ValueError:
raise aiohttp.web.HTTPBadRequest(text=f"invalid max_edges value: {s}")
[docs]
async def check_swhid(self, swhid):
"""Validate that the given SWHID exists in the graph"""
try:
await self.rpc_client.GetNode(
GetNodeRequest(swhid=swhid, mask=FieldMask(paths=["swhid"]))
)
except grpc.aio.AioRpcError as e:
if e.code() in (
grpc.StatusCode.INVALID_ARGUMENT,
grpc.StatusCode.NOT_FOUND, # Not used by Java backend, always "invalid"
):
raise aiohttp.web.HTTPBadRequest(text=str(e.details()))
[docs]
class StreamingGraphView(GraphView):
"""Base class for views streaming their response line by line."""
content_type = "text/plain"
[docs]
@asynccontextmanager
async def response_streamer(self, *args, **kwargs):
"""Context manager to prepare then close a StreamResponse"""
response = aiohttp.web.StreamResponse(*args, **kwargs)
response.content_type = self.content_type
await response.prepare(self.request)
yield response
await response.write_eof()
[docs]
async def get(self):
await self.prepare_response()
async with self.response_streamer() as self.response_stream:
self._buf = []
try:
await self.stream_response()
finally:
await self._flush_buffer()
return self.response_stream
[docs]
async def prepare_response(self):
"""This can be overridden with some setup to be run before the response
actually starts streaming.
"""
pass
[docs]
async def stream_response(self):
"""Override this to perform the response streaming. Implementations of
this should await self.stream_line(line) to write each line.
"""
raise NotImplementedError
[docs]
async def stream_line(self, line):
"""Write a line in the response stream."""
self._buf.append(line)
if len(self._buf) > 100:
await self._flush_buffer()
async def _flush_buffer(self):
await self.response_stream.write("\n".join(self._buf).encode() + b"\n")
self._buf = []
[docs]
class StatsView(GraphView):
"""View showing some statistics on the graph"""
[docs]
async def get(self):
res = await self.rpc_client.Stats(StatsRequest())
stats = json_format.MessageToDict(
res, including_default_value_fields=True, preserving_proto_field_name=True
)
# Int64 fields are serialized as strings by default.
for descriptor in res.DESCRIPTOR.fields:
if descriptor.type == descriptor.TYPE_INT64:
try:
stats[descriptor.name] = int(stats[descriptor.name])
except KeyError:
pass
json_body = json.dumps(stats, indent=4, sort_keys=True)
return aiohttp.web.Response(body=json_body, content_type="application/json")
[docs]
class SimpleTraversalView(StreamingGraphView):
"""Base class for views of simple traversals"""
[docs]
async def prepare_response(self):
src = self.request.match_info["src"]
self.traversal_request = TraversalRequest(
src=[src],
edges=self.get_edges(),
direction=self.get_direction(),
return_nodes=NodeFilter(types=self.get_return_types()),
mask=FieldMask(paths=["swhid"]),
max_matching_nodes=self.get_max_matching_nodes(),
)
if self.get_max_edges():
self.traversal_request.max_edges = self.get_max_edges()
await self.check_swhid(src)
self.configure_request()
self.nodes_stream = self.rpc_client.Traverse(
self.traversal_request,
)
# Force gRPC to query the server and fetch the first nodes; so errors
# are raised early, so we can return HTTP 503 before HTTP 200
await self.nodes_stream.wait_for_connection()
[docs]
async def stream_response(self):
async for node in self.nodes_stream:
await self.stream_line(node.swhid)
[docs]
class LeavesView(SimpleTraversalView):
[docs]
class NeighborsView(SimpleTraversalView):
[docs]
class VisitNodesView(SimpleTraversalView):
pass
[docs]
class VisitEdgesView(SimpleTraversalView):
# self.traversal_request.return_fields.successor = True
[docs]
async def stream_response(self):
async for node in self.nodes_stream:
for succ in node.successor:
await self.stream_line(node.swhid + " " + succ.swhid)
[docs]
class CountView(GraphView):
"""Base class for counting views."""
count_type: Optional[str] = None
[docs]
async def get(self):
src = self.request.match_info["src"]
self.traversal_request = TraversalRequest(
src=[src],
edges=self.get_edges(),
direction=self.get_direction(),
return_nodes=NodeFilter(types=self.get_return_types()),
mask=FieldMask(paths=["swhid"]),
max_matching_nodes=self.get_max_matching_nodes(),
)
if self.get_max_edges():
self.traversal_request.max_edges = self.get_max_edges()
self.configure_request()
res = await self.rpc_client.CountNodes(self.traversal_request)
return aiohttp.web.Response(
body=str(res.count), content_type="application/json"
)
[docs]
class CountNeighborsView(CountView):
[docs]
class CountLeavesView(CountView):
[docs]
class CountVisitNodesView(CountView):
pass
[docs]
def make_app(config=None):
"""Create an aiohttp server for the HTTP RPC frontend to the swh-graph API.
It may either connect to an existing grpc server (cls="remote") or spawn a
local grpc server (cls="local").
``config`` is expected to be a dict like::
graph:
cls: "local"
grpc_server:
port: 50091
http_rpc_server:
debug: true
or::
graph:
cls: "remote"
url: "localhost:50091"
http_rpc_server:
debug: true
See:
- :mod:`swh.graph.grpc_server` for more details of the content of the
grpc_server section,
- :class:`~.GraphServerApp` class for more details of the content of the
http_rpc_server section.
"""
if config is None:
config = {}
if "graph" not in config:
logger.info(
"Missing 'graph' configuration; default to a locally spawn"
"grpc server listening on 0.0.0.0:50091"
)
cfg = {"cls": "local", "grpc_server": {"port": 50091}}
else:
cfg = config["graph"].copy()
cls = cfg.pop("cls")
grpc_cfg = cfg.pop("grpc_server", {})
app = GraphServerApp(**cfg.get("http_rpc_server", {}))
if cls == "remote":
if "url" not in cfg:
raise KeyError("Missing 'url' configuration entry in the [graph] section")
rpc_url = cfg["url"]
elif cls in ("local", "local_rust"):
app["local_server"], port = spawn_rust_grpc_server(**grpc_cfg)
rpc_url = f"localhost:{port}"
else:
raise ValueError(f"Unknown swh.graph class cls={cls}")
app.add_routes(
[
aiohttp.web.get("/", index),
aiohttp.web.get("/graph", index),
aiohttp.web.view("/graph/stats", StatsView),
aiohttp.web.view("/graph/leaves/{src}", LeavesView),
aiohttp.web.view("/graph/neighbors/{src}", NeighborsView),
aiohttp.web.view("/graph/visit/nodes/{src}", VisitNodesView),
aiohttp.web.view("/graph/visit/edges/{src}", VisitEdgesView),
aiohttp.web.view("/graph/neighbors/count/{src}", CountNeighborsView),
aiohttp.web.view("/graph/leaves/count/{src}", CountLeavesView),
aiohttp.web.view("/graph/visit/nodes/count/{src}", CountVisitNodesView),
]
)
app["rpc_url"] = rpc_url
return app
[docs]
def make_app_from_configfile():
"""Load configuration and then build application to run"""
config_file = os.environ.get("SWH_CONFIG_FILENAME")
config = config_read(config_file)
return make_app(config=config)
