feat: improve aiohttp client error messages

This change is similar to
GoogleCloudPlatform/cloud-sql-python-connector#1201,
except for AlloyDB.

In short, we want to use the AlloyDB API's response body for error
messages, because they are more detailed.

Author: rhatgadkar-goog

google/cloud/alloydb/connector/client.py

@@ -124,8 +124,20 @@ async def _get_metadata(
 
         url = f"{self._alloydb_api_endpoint}/{API_VERSION}/projects/{project}/locations/{region}/clusters/{cluster}/instances/{name}/connectionInfo"
 
-        resp = await self._client.get(url, headers=headers, raise_for_status=True)
-        resp_dict = await resp.json()
+        resp = await self._client.get(url, headers=headers)
+        # try to get response json for better error message
+        try:
+            resp_dict = await resp.json()
+            if resp.status >= 400:
+                # if detailed error message is in json response, use as error message
+                message = resp_dict.get("error", {}).get("message")
+                if message:
+                    resp.reason = message
+        # skip, raise_for_status will catch all errors in finally block
+        except Exception:
+            pass
+        finally:
+            resp.raise_for_status()
 
         # Remove trailing period from PSC DNS name.
         psc_dns = resp_dict.get("pscDnsName")
@@ -175,10 +187,20 @@ async def _get_client_certificate(
             "useMetadataExchange": self._use_metadata,
         }
 
-        resp = await self._client.post(
-            url, headers=headers, json=data, raise_for_status=True
-        )
-        resp_dict = await resp.json()
+        resp = await self._client.post(url, headers=headers, json=data)
+        # try to get response json for better error message
+        try:
+            resp_dict = await resp.json()
+            if resp.status >= 400:
+                # if detailed error message is in json response, use as error message
+                message = resp_dict.get("error", {}).get("message")
+                if message:
+                    resp.reason = message
+        # skip, raise_for_status will catch all errors in finally block
+        except Exception:
+            pass
+        finally:
+            resp.raise_for_status()
 
         return (resp_dict["caCert"], resp_dict["pemCertificateChain"])
 

requirements-test.txt

@@ -6,3 +6,4 @@ pytest-asyncio==0.24.0
 pytest-cov==6.0.0
 pytest-aiohttp==1.0.5
 SQLAlchemy[asyncio]==2.0.36
+aioresponses==0.7.7

tests/unit/test_client.py

@@ -15,7 +15,8 @@
 import json
 from typing import Any, Optional
 
-from aiohttp import web
+from aiohttp import ClientResponseError, web
+from aioresponses import aioresponses
 from mocks import FakeCredentials
 import pytest
 
@@ -138,6 +139,76 @@ async def test__get_metadata_with_psc(
     }
 
 
+async def test__get_metadata_error(
+    credentials: FakeCredentials,
+) -> None:
+    """
+    Test that AlloyDB API error messages are raised for _get_metadata.
+    """
+    # mock AlloyDB API calls with exceptions
+    client = AlloyDBClient(
+        alloydb_api_endpoint="https://alloydb.googleapis.com",
+        quota_project=None,
+        credentials=credentials,
+    )
+    get_url = "https://alloydb.googleapis.com/v1beta/projects/my-project/locations/my-region/clusters/my-cluster/instances/my-instance/connectionInfo"
+    resp_body = {
+        "error": {
+            "code": 403,
+            "message": "AlloyDB API has not been used in project 123456789 before or it is disabled",
+        }
+    }
+    with aioresponses() as mocked:
+        mocked.get(
+            get_url,
+            status=403,
+            payload=resp_body,
+            repeat=True,
+        )
+        with pytest.raises(ClientResponseError) as exc_info:
+            await client._get_metadata("my-project", "my-region", "my-cluster", "my-instance")
+        exc = exc_info.value
+        assert exc.status == 403
+        assert (
+            exc.message
+            == "AlloyDB API has not been used in project 123456789 before or it is disabled"
+        )
+    await client.close()
+
+
+async def test__get_metadata_error_parsing_json(
+    credentials: FakeCredentials,
+) -> None:
+    """
+    Test that AlloyDB API error messages are raised for _get_metadata when
+    response JSON fails to be parsed.
+    """
+    # mock AlloyDB API calls with exceptions
+    client = AlloyDBClient(
+        alloydb_api_endpoint="https://alloydb.googleapis.com",
+        quota_project=None,
+        credentials=credentials,
+    )
+    get_url = "https://alloydb.googleapis.com/v1beta/projects/my-project/locations/my-region/clusters/my-cluster/instances/my-instance/connectionInfo"
+    resp_body = ["error"] # invalid json
+    with aioresponses() as mocked:
+        mocked.get(
+            get_url,
+            status=403,
+            payload=resp_body,
+            repeat=True,
+        )
+        with pytest.raises(ClientResponseError) as exc_info:
+            await client._get_metadata("my-project", "my-region", "my-cluster", "my-instance")
+        exc = exc_info.value
+        assert exc.status == 403
+        assert (
+            exc.message
+            != "AlloyDB API has not been used in project 123456789 before or it is disabled"
+        )
+    await client.close()
+
+
 @pytest.mark.asyncio
 async def test__get_client_certificate(
     client: Any, credentials: FakeCredentials
@@ -157,6 +228,70 @@ async def test__get_client_certificate(
     assert cert_chain[2] == "This is the root cert"
 
 
+async def test__get_client_certificate_error(
+    credentials: FakeCredentials,
+) -> None:
+    """
+    Test that AlloyDB API error messages are raised for _get_client_certificate.
+    """
+    # mock AlloyDB API calls with exceptions
+    client = AlloyDBClient(
+        alloydb_api_endpoint="https://alloydb.googleapis.com",
+        quota_project=None,
+        credentials=credentials,
+    )
+    post_url = "https://alloydb.googleapis.com/v1beta/projects/my-project/locations/my-region/clusters/my-cluster:generateClientCertificate"
+    resp_body = {
+        "error": {
+            "code": 404,
+            "message": "The AlloyDB instance does not exist.",
+        }
+    }
+    with aioresponses() as mocked:
+        mocked.post(
+            post_url,
+            status=404,
+            payload=resp_body,
+            repeat=True,
+        )
+        with pytest.raises(ClientResponseError) as exc_info:
+            await client._get_client_certificate("my-project", "my-region", "my-cluster", "")
+        exc = exc_info.value
+        assert exc.status == 404
+        assert exc.message == "The AlloyDB instance does not exist."
+    await client.close()
+
+
+async def test__get_client_certificate_error_parsing_json(
+    credentials: FakeCredentials,
+) -> None:
+    """
+    Test that AlloyDB API error messages are raised for _get_client_certificate
+    when response JSON fails to be parsed.
+    """
+    # mock AlloyDB API calls with exceptions
+    client = AlloyDBClient(
+        alloydb_api_endpoint="https://alloydb.googleapis.com",
+        quota_project=None,
+        credentials=credentials,
+    )
+    post_url = "https://alloydb.googleapis.com/v1beta/projects/my-project/locations/my-region/clusters/my-cluster:generateClientCertificate"
+    resp_body = ["error"] # invalid json
+    with aioresponses() as mocked:
+        mocked.post(
+            post_url,
+            status=404,
+            payload=resp_body,
+            repeat=True,
+        )
+        with pytest.raises(ClientResponseError) as exc_info:
+            await client._get_client_certificate("my-project", "my-region", "my-cluster", "")
+        exc = exc_info.value
+        assert exc.status == 404
+        assert exc.message != "The AlloyDB instance does not exist."
+    await client.close()
+
+
 @pytest.mark.asyncio
 async def test_AlloyDBClient_init_(credentials: FakeCredentials) -> None:
     """