gql-cli add --transport argument (#281)

Author: leszekhanusz

docs/transports/appsync.rst

@@ -154,3 +154,31 @@ a normal http session and reuse the authentication classes to create the headers
 Full example with API key authentication from environment variables:
 
 .. literalinclude:: ../code_examples/appsync/mutation_api_key.py
+
+From the command line
+---------------------
+
+Using :ref:`gql-cli <gql_cli>`, it is possible to execute GraphQL queries and subscriptions
+from the command line on an AppSync endpoint.
+
+- For queries and mutations, use the :code:`--transport appsync_http` argument::
+
+    # Put the request in a file
+    $ echo 'mutation createMessage($message: String!) {
+      createMessage(input: {message: $message}) {
+        id
+        message
+        createdAt
+      }
+    }' > mutation.graphql
+
+    # Execute the request using gql-cli with --transport appsync_http
+    $ cat mutation.graphql | gql-cli $AWS_GRAPHQL_API_ENDPOINT --transport appsync_http -V message:"Hello world!"
+
+- For subscriptions, use the :code:`--transport appsync_websockets` argument::
+
+    echo "subscription{onCreateMessage{message}}" | gql-cli $AWS_GRAPHQL_API_ENDPOINT --transport appsync_websockets
+
+- You can also get the full GraphQL schema from the backend from introspection::
+
+    $ gql-cli $AWS_GRAPHQL_API_ENDPOINT --transport appsync_http --print-schema > schema.graphql

gql/cli.py

@@ -2,7 +2,7 @@
 import logging
 import sys
 from argparse import ArgumentParser, Namespace, RawDescriptionHelpFormatter
-from typing import Any, Dict
+from typing import Any, Dict, Optional
 
 from graphql import GraphQLError, print_schema
 from yarl import URL
@@ -101,6 +101,43 @@ def get_parser(with_examples: bool = False) -> ArgumentParser:
         action="store_true",
         dest="print_schema",
     )
+    parser.add_argument(
+        "--transport",
+        default="auto",
+        choices=[
+            "auto",
+            "aiohttp",
+            "phoenix",
+            "websockets",
+            "appsync_http",
+            "appsync_websockets",
+        ],
+        help=(
+            "select the transport. 'auto' by default: "
+            "aiohttp or websockets depending on url scheme"
+        ),
+        dest="transport",
+    )
+
+    appsync_description = """
+By default, for an AppSync backend, the IAM authentication is chosen.
+
+If you want API key or JWT authentication, you can provide one of the
+following arguments:"""
+
+    appsync_group = parser.add_argument_group(
+        "AWS AppSync options", description=appsync_description
+    )
+
+    appsync_auth_group = appsync_group.add_mutually_exclusive_group()
+
+    appsync_auth_group.add_argument(
+        "--api-key", help="Provide an API key for authentication", dest="api_key",
+    )
+
+    appsync_auth_group.add_argument(
+        "--jwt", help="Provide an JSON Web token for authentication", dest="jwt",
+    )
 
     return parser
 
@@ -191,36 +228,106 @@ def get_execute_args(args: Namespace) -> Dict[str, Any]:
     return execute_args
 
 
-def get_transport(args: Namespace) -> AsyncTransport:
+def autodetect_transport(url: URL) -> str:
+    """Detects which transport should be used depending on url."""
+
+    if url.scheme in ["ws", "wss"]:
+        transport_name = "websockets"
+
+    else:
+        assert url.scheme in ["http", "https"]
+        transport_name = "aiohttp"
+
+    return transport_name
+
+
+def get_transport(args: Namespace) -> Optional[AsyncTransport]:
     """Instantiate a transport from the parsed command line arguments
 
     :param args: parsed command line arguments
     """
 
     # Get the url scheme from server parameter
     url = URL(args.server)
-    scheme = url.scheme
+
+    # Validate scheme
+    if url.scheme not in ["http", "https", "ws", "wss"]:
+        raise ValueError("URL protocol should be one of: http, https, ws, wss")
 
     # Get extra transport parameters from command line arguments
     # (headers)
     transport_args = get_transport_args(args)
 
-    # Instantiate transport depending on url scheme
-    transport: AsyncTransport
-    if scheme in ["ws", "wss"]:
-        from gql.transport.websockets import WebsocketsTransport
+    # Either use the requested transport or autodetect it
+    if args.transport == "auto":
+        transport_name = autodetect_transport(url)
+    else:
+        transport_name = args.transport
 
-        transport = WebsocketsTransport(
-            url=args.server, ssl=(scheme == "wss"), **transport_args
-        )
-    elif scheme in ["http", "https"]:
+    # Import the correct transport class depending on the transport name
+    if transport_name == "aiohttp":
         from gql.transport.aiohttp import AIOHTTPTransport
 
-        transport = AIOHTTPTransport(url=args.server, **transport_args)
+        return AIOHTTPTransport(url=args.server, **transport_args)
+
+    elif transport_name == "phoenix":
+        from gql.transport.phoenix_channel_websockets import (
+            PhoenixChannelWebsocketsTransport,
+        )
+
+        return PhoenixChannelWebsocketsTransport(url=args.server, **transport_args)
+
+    elif transport_name == "websockets":
+        from gql.transport.websockets import WebsocketsTransport
+
+        transport_args["ssl"] = url.scheme == "wss"
+
+        return WebsocketsTransport(url=args.server, **transport_args)
+
     else:
-        raise ValueError("URL protocol should be one of: http, https, ws, wss")
 
-    return transport
+        from gql.transport.appsync_auth import AppSyncAuthentication
+
+        assert transport_name in ["appsync_http", "appsync_websockets"]
+        assert url.host is not None
+
+        auth: AppSyncAuthentication
+
+        if args.api_key:
+            from gql.transport.appsync_auth import AppSyncApiKeyAuthentication
+
+            auth = AppSyncApiKeyAuthentication(host=url.host, api_key=args.api_key)
+
+        elif args.jwt:
+            from gql.transport.appsync_auth import AppSyncJWTAuthentication
+
+            auth = AppSyncJWTAuthentication(host=url.host, jwt=args.jwt)
+
+        else:
+            from gql.transport.appsync_auth import AppSyncIAMAuthentication
+            from botocore.exceptions import NoRegionError
+
+            try:
+                auth = AppSyncIAMAuthentication(host=url.host)
+            except NoRegionError:
+                # A warning message has been printed in the console
+                return None
+
+        transport_args["auth"] = auth
+
+        if transport_name == "appsync_http":
+            from gql.transport.aiohttp import AIOHTTPTransport
+
+            return AIOHTTPTransport(url=args.server, **transport_args)
+
+        else:
+            from gql.transport.appsync_websockets import AppSyncWebsocketsTransport
+
+            try:
+                return AppSyncWebsocketsTransport(url=args.server, **transport_args)
+            except Exception:
+                # This is for the NoCredentialsError but we cannot import it here
+                return None
 
 
 async def main(args: Namespace) -> int:
@@ -238,13 +345,16 @@ async def main(args: Namespace) -> int:
         # Instantiate transport from command line arguments
         transport = get_transport(args)
 
+        if transport is None:
+            return 1
+
         # Get extra execute parameters from command line arguments
         # (variables, operation_name)
         execute_args = get_execute_args(args)
 
     except ValueError as e:
         print(f"Error: {e}", file=sys.stderr)
-        sys.exit(1)
+        return 1
 
     # By default, the exit_code is 0 (everything is ok)
     exit_code = 0

gql/transport/appsync_auth.py

@@ -54,7 +54,7 @@ def __init__(self, host: str, api_key: str) -> None:
                      XXXXXXXXXXXXXXXXXXXXXXXXXX.appsync-api.REGION.amazonaws.com
         :param api_key: the API key
         """
-        self._host = host
+        self._host = host.replace("appsync-realtime-api", "appsync-api")
         self.api_key = api_key
 
     def get_headers(
@@ -77,7 +77,7 @@ def __init__(self, host: str, jwt: str) -> None:
                      XXXXXXXXXXXXXXXXXXXXXXXXXX.appsync-api.REGION.amazonaws.com
         :param jwt: the JWT Access Token
         """
-        self._host = host
+        self._host = host.replace("appsync-realtime-api", "appsync-api")
         self.jwt = jwt
 
     def get_headers(
@@ -120,7 +120,7 @@ def __init__(
         from botocore.awsrequest import create_request_object
         from botocore.session import get_session
 
-        self._host = host
+        self._host = host.replace("appsync-realtime-api", "appsync-api")
         self._session = session if session else get_session()
         self._credentials = (
             credentials if credentials else self._session.get_credentials()
@@ -201,7 +201,7 @@ def get_headers(
             self._signer.add_auth(request)
         except NoCredentialsError:
             log.warning(
-                "Credentials not found. "
+                "Credentials not found for the IAM auth. "
                 "Do you have default AWS credentials configured?",
             )
             raise

tests/test_aiohttp.py

@@ -994,9 +994,9 @@ async def handler(request):
     # via the standard input
     monkeypatch.setattr("sys.stdin", io.StringIO(query1_str))
 
-    # Checking that sys.exit() is called
-    with pytest.raises(SystemExit):
-        await main(args)
+    # Check that the exit_code is an error
+    exit_code = await main(args)
+    assert exit_code == 1
 
     # Check that the error has been printed on stdout
     captured = capsys.readouterr()