Support canonical subject

Also support resource URIs with slashes

Misc: Better OpenAPI examples and docstrings

pyproject.toml

@@ -16,4 +16,6 @@ license = {text = "AGPL"}
 requires = ["pdm-pep517>=1.0.0"]
 build-backend = "pdm.pep517.api"
 
-[tool.pdm]
+[tool.pdm.scripts]
+dev = "uvicorn webfinger:app --port 7033 --reload"
+start = "python -m webfinger"

webfinger/__init__.py

@@ -3,7 +3,7 @@ import webfinger.lookup
 
 app = FastAPI(
 	title = "webfinger",
-	version = "2"
+	version = "1"
 )
 
 app.include_router(webfinger.lookup.router)

webfinger/io.py

@@ -1,19 +1,44 @@
 import json
 from os import environ as env
+from urllib.parse import quote_plus as url_encode
 from pathlib import Path
 
-def get_document(resource: str) -> dict | None:
+def get_jrd(resource: str) -> dict[str, str | list[str] | dict[str,str]]:
+	"""
+	Obtain a JSON Resource Descriptor (JRD)
+
+	A JRD is a JSON object containing the following:
+	- subject (string value; SHOULD be present)
+	- aliases (array of string values; OPTIONAL)
+	- properties (object containing key-value pairs as strings; OPTIONAL)
+	- links (array of objects containing link relation information; OPTIONAL)
+
+	Parameters:
+		resource (str): The URI of the resouce
+	
+	Returns:
+		jrd (dict): Parsed JRD
+
+	Raises:
+		FileNotFoundError: No JRD file exists in the resource directory
+		OSError: A file may exist, but it is not readable
+		json.JSONDecodeError: A file exists, but does not contain a valid JSON object
+	"""
 	# Get a filename for the resource document.
 	dir = env.get("RESOURCE_DIR") or "resource"
-	filename = f"{dir}/{resource}.json"
+	filename = resource
+	path = f"{dir}/{filename}.json"
 
-	# Check that the file exists.
-	path = Path(filename)
-	if not path:
-		return None
+	# If we can't get a file, try percent-encoding
+	if not Path(path).is_file():
+		filename = url_encode(resource)
+		path = f"{dir}/{filename}.json"
 
 	# Open the file and load the JSON as a dictionary.
-	with open(filename, "r") as file:
-		data: dict = json.loads(file.read())
+	try:
+		with open(path, "r") as file:
+			jrd: dict[str, str | list[str] | dict[str,str]] = json.loads(file.read())
+	except:
+		raise
 
-	return data
+	return jrd

webfinger/lookup.py

@@ -3,8 +3,9 @@ from fastapi.responses import PlainTextResponse, JSONResponse
 from fastapi.params import Query
 
 from pydantic import BaseModel
+import json
 
-from webfinger.io import get_document
+from webfinger.io import get_jrd
 
 
 router = APIRouter(
@@ -16,26 +17,6 @@ router = APIRouter(
 
 MEDIA_TYPE = "application/jrd+json"
 
-EXAMPLE_RESOURCE = r'''
-{
-	"aliases": ["https://trwnh.com/actors/7057bc10-db1c-4ebe-9e00-22cf04be4e5e", "https://trwnh.com/~a"],
-	"links": [
-		{
-			"rel": "self",
-			"type": "application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\"",
-			"href": "https://trwnh.com/actors/7057bc10-db1c-4ebe-9e00-22cf04be4e5e"
-		},
-		{
-			"rel": "https://webfinger.net/rel/profile-page/",
-			"type": "text/html",
-			"href": "https://trwnh.com/~a"
-		}
-	]
-}
-'''
-
-NO_RESOURCE_HINT = "Query ?resource={resource} to obtain information about that resource."
-
 
 ## Pydantic models for OpenAPI schema
 
@@ -48,54 +29,81 @@ class Link(BaseModel):
 
 	class Config:
 		schema_extra = {
-			"example": '''{
-			"rel": "https://webfinger.net/rel/profile-page/",
-			"type": "text/html",
-			"href": "https://trwnh.com/~a"
-		}'''
+			"example": r'''{
+				"rel": "https://webfinger.net/rel/profile-page/",
+				"type": "text/html",
+				"href": "https://trwnh.com/~a"
+			}'''
 		}
 
-class Resource(BaseModel):
+class JRD(BaseModel):
 	subject: str
 	aliases: list[str] | None
 	links: list[Link] | None
 
 	class Config:
 		schema_extra = {
-			"example": EXAMPLE_RESOURCE
+			"example": r'''{
+				"subject": "acct:a@trwnh.com",
+				"aliases": ["https://trwnh.com/actors/7057bc10-db1c-4ebe-9e00-22cf04be4e5e", "https://trwnh.com/~a", "acct:trwnh@trwnh.com"],
+				"links": [
+					{
+						"rel": "self",
+						"type": "application/ld+json; profile=\"https://www.w3.org/ns/activitystreams\"",
+						"href": "https://trwnh.com/actors/7057bc10-db1c-4ebe-9e00-22cf04be4e5e"
+					},
+					{
+						"rel": "https://webfinger.net/rel/profile-page/",
+						"type": "text/html",
+						"href": "https://trwnh.com/~a"
+					}
+				]
+			}'''
 		}
 
-class WebfingerResponse(Response):
+class JRDResponse(Response):
 	media_type = MEDIA_TYPE
 
 
 ## Example responses for OpenAPI schema
 
+RESOURCE_NOT_PROVIDED = "Query ?resource={resource} to obtain information about that resource."
+RESOURCE_NOT_FOUND = "Resource not found"
+RESOURCE_NOT_PARSED = "Resource contains invalid JSON or was unreadable"
+
 RESPONSES = {
+	200: {
+		"description": "OK: The resource you requested was found, and has the returned resource document.",
+		"model": JRD,
+		"content": {
+			MEDIA_TYPE: {
+				"example": json.loads(JRD.Config.schema_extra['example']),
+			},
+		},
+	},
 	400: {
-		"description": "Bad Request. No resource was provided.",
+		"description": "Bad Request: No resource was provided.",
 		"content": {
 			"text/plain": {
-				"example": NO_RESOURCE_HINT
-			}
+				"example": RESOURCE_NOT_PROVIDED
+			},
 		},
 	},
 	404: {
-		"description": "Not Found. Could not find a document for the provided resource.",
+		"description": "Not Found: Could not find a document for the provided resource.",
 		"content": {
 			"text/plain": {
-				"example": "{resource} not found"
-			}
+				"example": RESOURCE_NOT_FOUND
+			},
 		},
 	},
-	200: {
-		"description": "The resource you requested was found, and has the returned resource document.",
-		"model": Resource,
+	500: {
+		"description": "Server Error: The resource exists, but contains invalid JSON or was unreadable.",
 		"content": {
-			MEDIA_TYPE: {
-				"example": EXAMPLE_RESOURCE
-			}
-		}
+			"text/plain": {
+				"example": RESOURCE_NOT_PARSED
+			},
+		},
 	},
 }
 
@@ -107,46 +115,52 @@ RESPONSES = {
 	summary = "Lookup a Webfinger resource",
 	description = "Query the Webfinger service for a resource URI and obtain its associated resource document",
 	tags = ["RFC7033"],
-	response_model = Resource,
-	response_class = WebfingerResponse,
+	response_model = JRD,
+	response_class = JRDResponse,
 	responses = {**RESPONSES},
 
 )
 async def lookup(
 	resource: str = Query(
 		None,
+		title = "Resource URI",
 		description = "The subject whose document you are looking up. If not provided, you will get a 400 Bad Request."
 		),
 	rel: list[str] = Query(
 		None,
+		title = "Link relation",
 		description = "If provided, filter the links array for this rel-value only. This parameter may be included multiple times."
 		)
 	):
 	"""
 	Respond to a WebFinger query.
 	"""
-
 	# If no resource is given, then show a basic hint.
 	if not resource:
 		return PlainTextResponse(
-			content=NO_RESOURCE_HINT,
+			content=RESOURCE_NOT_PROVIDED,
 			status_code=400,
 		)
 	
 	# Otherwise, try to read the resource document.
-	data = get_document(resource)
-
-	# If the document could not be read, then it likely didn't exist.
-	if data is None:
+	try:
+		jrd = get_jrd(resource)
+	except FileNotFoundError:  # JRD file does not exist
 		return PlainTextResponse(
-			content=f"{resource} not found",
+			content=RESOURCE_NOT_FOUND,
 			status_code=404,
 		)
+	except:  # JRD file could not be read or parsed
+		return PlainTextResponse(
+			content=RESOURCE_NOT_PARSED,
+			status_code=500,
+		)
 
 	# Obtain values from the resource document.
-	aliases = [alias for alias in data.get('aliases', [])]
-	links = [link for link in data.get('links', [])]
-	properties = data.get('properties', {})
+	subject: str = jrd.get('subject', None) or resource
+	aliases: list[str] = [alias for alias in jrd.get('aliases', [])]
+	properties: dict[str, str] = jrd.get('properties', {})
+	links: list[dict[str,str]] = [link for link in jrd.get('links', [])]
 
 	# If optional rel is provided, then filter only for links with that rel-type.
 	if rel:
@@ -154,7 +168,7 @@ async def lookup(
 
 	# Construct JSON response and return it.
 	content = {
-		"subject": resource,
+		"subject": subject,
 		"aliases": aliases,
 		"properties": properties,
 		"links": links,