grpc-plugin: Generate mTLS certificates and use them in grpc

tests/test_cln_rs.py

@@ -63,3 +63,65 @@ def test_plugin_start(node_factory):
     l1.connect(l2)
     l1.daemon.wait_for_log(r'Got a connect hook call')
     l1.daemon.wait_for_log(r'Got a connect notification')
+
+
+def test_grpc_connect(node_factory):
+    """Attempts to connect to the grpc interface and call getinfo"""
+    bin_path = Path.cwd() / "target" / "debug" / "grpc-plugin"
+    l1 = node_factory.get_node(options={"plugin": str(bin_path)})
+
+    p = Path(l1.daemon.lightning_dir) / TEST_NETWORK
+    cert_path = p / "client.pem"
+    key_path = p / "client-key.pem"
+    ca_cert_path = p / "ca.pem"
+    creds = grpc.ssl_channel_credentials(
+        root_certificates=ca_cert_path.open('rb').read(),
+        private_key=key_path.open('rb').read(),
+        certificate_chain=cert_path.open('rb').read()
+    )
+
+    channel = grpc.secure_channel(
+        "localhost:50051",
+        creds,
+        options=(('grpc.ssl_target_name_override', 'cln'),)
+    )
+    stub = NodeStub(channel)
+
+    response = stub.Getinfo(nodepb.GetinfoRequest())
+    print(response)
+
+    response = stub.ListFunds(nodepb.ListfundsRequest())
+    print(response)
+
+
+def test_grpc_generate_certificate(node_factory):
+    """Test whether we correctly generate the certificates.
+
+     - If we have no certs, we need to generate them all
+     - If we have certs, we they should just get loaded
+     - If we delete one cert or its key it should get regenerated.
+    """
+    bin_path = Path.cwd() / "target" / "debug" / "grpc-plugin"
+    l1 = node_factory.get_node(options={
+        "plugin": str(bin_path),
+    }, start=False)
+
+    p = Path(l1.daemon.lightning_dir) / TEST_NETWORK
+    files = [p / f for f in ['ca.pem', 'ca-key.pem', 'client.pem', 'client-key.pem', 'server-key.pem', 'server.pem']]
+
+    # Before starting no files exist.
+    assert [f.exists() for f in files] == [False] * len(files)
+
+    l1.start()
+    assert [f.exists() for f in files] == [True] * len(files)
+
+    # The files exist, restarting should not change them
+    contents = [f.open().read() for f in files]
+    l1.restart()
+    assert contents == [f.open().read() for f in files]
+
+    # Now we delete the last file, we should regenerate it as well as its key
+    files[-1].unlink()
+    l1.restart()
+    assert contents[-2] != files[-2].open().read()
+    assert contents[-1] != files[-1].open().read()