feat(flagd): add custom cert path (#131)

feat(flagd): add ssl cert path option

Signed-off-by: Simon Schrottner <[email protected]>

Author: aepfli

providers/openfeature-provider-flagd/README.md

@@ -47,11 +47,12 @@ api.set_provider(FlagdProvider(
 The default options can be defined in the FlagdProvider constructor.
 
 | Option name              | Environment variable name      | Type & Values              | Default                       | Compatible resolver |
-| ------------------------ | ------------------------------ | -------------------------- | ----------------------------- | ------------------- |
+|--------------------------|--------------------------------|----------------------------|-------------------------------|---------------------|
 | resolver_type            | FLAGD_RESOLVER                 | enum - `rpc`, `in-process` | rpc                           |                     |
 | host                     | FLAGD_HOST                     | str                        | localhost                     | rpc & in-process    |
 | port                     | FLAGD_PORT                     | int                        | 8013 (rpc), 8015 (in-process) | rpc & in-process    |
 | tls                      | FLAGD_TLS                      | bool                       | false                         | rpc & in-process    |
+| cert_path                | FLAGD_SERVER_CERT_PATH         | String                     | null                          | rpc & in-process    |
 | deadline                 | FLAGD_DEADLINE_MS              | int                        | 500                           | rpc & in-process    |
 | stream_deadline_ms       | FLAGD_STREAM_DEADLINE_MS       | int                        | 600000                        | rpc & in-process    |
 | keep_alive_time          | FLAGD_KEEP_ALIVE_TIME_MS       | int                        | 0                             | rpc & in-process    |
@@ -64,8 +65,6 @@ The default options can be defined in the FlagdProvider constructor.
 <!-- not implemented
 | target_uri               | FLAGD_TARGET_URI               | alternative to host/port, supporting custom name resolution | string    | null                | rpc & in-process |
 | socket_path              | FLAGD_SOCKET_PATH              | alternative to host port, unix socket                       | String    | null                | rpc & in-process |
-| cert_path                | FLAGD_SERVER_CERT_PATH         | tls cert path                                               | String    | null                | rpc & in-process |
-| max_event_stream_retries | FLAGD_MAX_EVENT_STREAM_RETRIES | int                                                         | 5         | rpc                 |
 | context_enricher         | -                              | sync-metadata to evaluation context mapping function        | function  | identity function   | in-process       |
 | offline_pollIntervalMs   | FLAGD_OFFLINE_POLL_MS          | poll interval for reading offlineFlagSourcePath             | int       | 5000                | in-process       |
  -->
@@ -100,17 +99,18 @@ and the evaluation will default.
 
 TLS is available in situations where flagd is running on another host.
 
-<!--
+
 You may optionally supply an X.509 certificate in PEM format. Otherwise, the default certificate store will be used.
-```java
-FlagdProvider flagdProvider = new FlagdProvider(
-        FlagdOptions.builder()
-                .host("myflagdhost")
-                .tls(true)                      // use TLS
-                .certPath("etc/cert/ca.crt")    // PEM cert
-                .build());
+
+```python
+from openfeature import api
+from openfeature.contrib.provider.flagd import FlagdProvider
+
+api.set_provider(FlagdProvider(
+    tls=True,                        # use TLS
+    cert_path="etc/cert/ca.crt"      # PEM cert
+))
 ```
--->
 
 ## License
 

providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/config.py

@@ -29,6 +29,7 @@ class CacheType(Enum):
 DEFAULT_RETRY_GRACE_PERIOD_SECONDS = 5
 DEFAULT_STREAM_DEADLINE = 600000
 DEFAULT_TLS = False
+DEFAULT_TLS_CERT: typing.Optional[str] = None
 
 ENV_VAR_CACHE_SIZE = "FLAGD_MAX_CACHE_SIZE"
 ENV_VAR_CACHE_TYPE = "FLAGD_CACHE"
@@ -44,6 +45,7 @@ class CacheType(Enum):
 ENV_VAR_RETRY_GRACE_PERIOD_SECONDS = "FLAGD_RETRY_GRACE_PERIOD"
 ENV_VAR_STREAM_DEADLINE_MS = "FLAGD_STREAM_DEADLINE_MS"
 ENV_VAR_TLS = "FLAGD_TLS"
+ENV_VAR_TLS_CERT = "FLAGD_SERVER_CERT_PATH"
 
 T = typing.TypeVar("T")
 
@@ -87,6 +89,7 @@ def __init__(  # noqa: PLR0913
         keep_alive_time: typing.Optional[int] = None,
         cache: typing.Optional[CacheType] = None,
         max_cache_size: typing.Optional[int] = None,
+        cert_path: typing.Optional[str] = None,
     ):
         self.host = env_or_default(ENV_VAR_HOST, DEFAULT_HOST) if host is None else host
 
@@ -200,3 +203,9 @@ def __init__(  # noqa: PLR0913
             if max_cache_size is None
             else max_cache_size
         )
+
+        self.cert_path = (
+            env_or_default(ENV_VAR_TLS_CERT, DEFAULT_TLS_CERT)
+            if cert_path is None
+            else cert_path
+        )

providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/provider.py

@@ -54,6 +54,7 @@ def __init__(  # noqa: PLR0913
         max_cache_size: typing.Optional[int] = None,
         retry_backoff_max_ms: typing.Optional[int] = None,
         retry_grace_period: typing.Optional[int] = None,
+        cert_path: typing.Optional[str] = None,
     ):
         """
         Create an instance of the FlagdProvider
@@ -91,6 +92,7 @@ def __init__(  # noqa: PLR0913
             keep_alive_time=keep_alive_time,
             cache=cache_type,
             max_cache_size=max_cache_size,
+            cert_path=cert_path,
         )
 
         self.resolver = self.setup_resolver()

providers/openfeature-provider-flagd/src/openfeature/contrib/provider/flagd/resolvers/grpc.py

@@ -64,25 +64,41 @@ def __init__(
         self.streamline_deadline_seconds = config.stream_deadline_ms * 0.001
         self.deadline = config.deadline_ms * 0.001
         self.connected = False
-        channel_factory = grpc.secure_channel if config.tls else grpc.insecure_channel
+        self.channel = self._generate_channel(config)
+        self.stub = evaluation_pb2_grpc.ServiceStub(self.channel)
+
+        self.thread: typing.Optional[threading.Thread] = None
+        self.timer: typing.Optional[threading.Timer] = None
 
+        self.start_time = time.time()
+
+    def _generate_channel(self, config: Config) -> grpc.Channel:
+        target = f"{config.host}:{config.port}"
         # Create the channel with the service config
         options = [
             ("grpc.keepalive_time_ms", config.keep_alive_time),
             ("grpc.initial_reconnect_backoff_ms", config.retry_backoff_ms),
             ("grpc.max_reconnect_backoff_ms", config.retry_backoff_max_ms),
             ("grpc.min_reconnect_backoff_ms", config.deadline_ms),
         ]
-        self.channel = channel_factory(
-            f"{config.host}:{config.port}",
-            options=options,
-        )
-        self.stub = evaluation_pb2_grpc.ServiceStub(self.channel)
-
-        self.thread: typing.Optional[threading.Thread] = None
-        self.timer: typing.Optional[threading.Timer] = None
+        if config.tls:
+            channel_args = {
+                "options": options,
+                "credentials": grpc.ssl_channel_credentials(),
+            }
+            if config.cert_path:
+                with open(config.cert_path, "rb") as f:
+                    channel_args["credentials"] = grpc.ssl_channel_credentials(f.read())
+
+            channel = grpc.secure_channel(target, **channel_args)
+
+        else:
+            channel = grpc.insecure_channel(
+                target,
+                options=options,
+            )
 
-        self.start_time = time.time()
+        return channel
 
     def initialize(self, evaluation_context: EvaluationContext) -> None:
         self.connect()

providers/openfeature-provider-flagd/tests/e2e/test_rpc_ssl.py

@@ -0,0 +1,68 @@
+from pathlib import Path
+
+import pytest
+from pytest_bdd import given, scenarios
+from tests.e2e.conftest import SPEC_PATH
+from tests.e2e.flagd_container import FlagdContainer
+from tests.e2e.steps import wait_for
+
+from openfeature import api
+from openfeature.client import OpenFeatureClient
+from openfeature.contrib.provider.flagd import FlagdProvider
+from openfeature.contrib.provider.flagd.config import ResolverType
+from openfeature.provider import ProviderStatus
+
+
+@pytest.fixture(autouse=True, scope="module")
+def client_name() -> str:
+    return "rpc"
+
+
+@pytest.fixture(autouse=True, scope="module")
+def resolver_type() -> ResolverType:
+    return ResolverType.RPC
+
+
+@pytest.fixture(autouse=True, scope="module")
+def port():
+    return 8013
+
+
+@pytest.fixture(autouse=True, scope="module")
+def image():
+    return "ghcr.io/open-feature/flagd-testbed-ssl"
+
+
+@given("a flagd provider is set", target_fixture="client")
+@given("a provider is registered", target_fixture="client")
+def setup_provider(
+    container: FlagdContainer, resolver_type, client_name, port
+) -> OpenFeatureClient:
+    try:
+        container.get_exposed_port(port)
+    except:  # noqa: E722
+        container.start()
+
+    path = (
+        Path(__file__).parents[2] / "openfeature/test-harness/ssl/custom-root-cert.crt"
+    )
+
+    api.set_provider(
+        FlagdProvider(
+            resolver_type=resolver_type,
+            port=int(container.get_exposed_port(port)),
+            timeout=1,
+            retry_grace_period=3,
+            tls=True,
+            cert_path=str(path.absolute()),
+        ),
+        client_name,
+    )
+    client = api.get_client(client_name)
+    wait_for(lambda: client.get_provider_status() == ProviderStatus.READY)
+    return client
+
+
+scenarios(
+    f"{SPEC_PATH}/specification/assets/gherkin/evaluation.feature",
+)