From f984c9b178e595292d4a6934ce229c9854c2fe77 Mon Sep 17 00:00:00 2001 From: Krisztian Litkey Date: Fri, 23 Jun 2023 19:51:07 +0300 Subject: [PATCH] client: implement UnaryClientInterceptor chaining. Add a WithChainUnaryClientInterceptor client option to allow using more that one client call interceptor which will then get chained and invoked in the order given. This should allow us to implement opentelemetry instrumentation as interceptors while allowing users to keep intercepting their client calls for other reasons at the same time. Signed-off-by: Krisztian Litkey --- client.go | 41 +++++++++++++- interceptor_test.go | 135 ++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 175 insertions(+), 1 deletion(-) create mode 100644 interceptor_test.go diff --git a/client.go b/client.go index 4b1e1e7..446e38a 100644 --- a/client.go +++ b/client.go @@ -71,6 +71,42 @@ func WithUnaryClientInterceptor(i UnaryClientInterceptor) ClientOpts { } } +// WithChainUnaryClientInterceptor sets the provided chain of client interceptors +func WithChainUnaryClientInterceptor(interceptors ...UnaryClientInterceptor) ClientOpts { + return func(c *Client) { + if len(interceptors) == 0 { + return + } + if c.interceptor != nil { + interceptors = append([]UnaryClientInterceptor{c.interceptor}, interceptors...) + } + c.interceptor = func( + ctx context.Context, + req *Request, + reply *Response, + info *UnaryClientInfo, + final Invoker, + ) error { + return interceptors[0](ctx, req, reply, info, + chainUnaryInterceptors(interceptors[1:], final, info)) + } + } +} + +func chainUnaryInterceptors(interceptors []UnaryClientInterceptor, final Invoker, info *UnaryClientInfo) Invoker { + if len(interceptors) == 0 { + return final + } + return func( + ctx context.Context, + req *Request, + reply *Response, + ) error { + return interceptors[0](ctx, req, reply, info, + chainUnaryInterceptors(interceptors[1:], final, info)) + } +} + // NewClient creates a new ttrpc client using the given connection func NewClient(conn net.Conn, opts ...ClientOpts) *Client { ctx, cancel := context.WithCancel(context.Background()) @@ -85,13 +121,16 @@ func NewClient(conn net.Conn, opts ...ClientOpts) *Client { ctx: ctx, userCloseFunc: func() {}, userCloseWaitCh: make(chan struct{}), - interceptor: defaultClientInterceptor, } for _, o := range opts { o(c) } + if c.interceptor == nil { + c.interceptor = defaultClientInterceptor + } + go c.run() return c } diff --git a/interceptor_test.go b/interceptor_test.go new file mode 100644 index 0000000..39d82f8 --- /dev/null +++ b/interceptor_test.go @@ -0,0 +1,135 @@ +/* + Copyright The containerd Authors. + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. +*/ + +package ttrpc + +import ( + "context" + "reflect" + "strings" + "testing" + + "github.com/containerd/ttrpc/internal" +) + +func TestUnaryClientInterceptor(t *testing.T) { + var ( + intercepted = false + interceptor = func(ctx context.Context, req *Request, reply *Response, ci *UnaryClientInfo, i Invoker) error { + intercepted = true + return i(ctx, req, reply) + } + + ctx = context.Background() + server = mustServer(t)(NewServer()) + testImpl = &testingServer{} + addr, listener = newTestListener(t) + client, cleanup = newTestClient(t, addr, WithUnaryClientInterceptor(interceptor)) + message = strings.Repeat("a", 16) + reply = strings.Repeat(message, 2) + ) + + defer listener.Close() + defer cleanup() + + registerTestingService(server, testImpl) + + go server.Serve(ctx, listener) + defer server.Shutdown(ctx) + + request := &internal.TestPayload{ + Foo: message, + } + response := &internal.TestPayload{} + + if err := client.Call(ctx, serviceName, "Test", request, response); err != nil { + t.Fatalf("unexpected error: %v", err) + } + + if !intercepted { + t.Fatalf("ttrpc client call not intercepted") + } + + if response.Foo != reply { + t.Fatalf("unexpected test service reply: %q != %q", response.Foo, reply) + } +} + +func TestChainUnaryClientInterceptor(t *testing.T) { + var ( + orderIdx = 0 + recorded = []string{} + intercept = func(idx int, tag string) UnaryClientInterceptor { + return func(ctx context.Context, req *Request, reply *Response, ci *UnaryClientInfo, i Invoker) error { + if idx != orderIdx { + t.Fatalf("unexpected interceptor invocation order (%d != %d)", orderIdx, idx) + } + recorded = append(recorded, tag) + orderIdx++ + return i(ctx, req, reply) + } + } + + ctx = context.Background() + server = mustServer(t)(NewServer()) + testImpl = &testingServer{} + addr, listener = newTestListener(t) + client, cleanup = newTestClient(t, addr, + WithChainUnaryClientInterceptor(), + WithChainUnaryClientInterceptor( + intercept(0, "seen it"), + intercept(1, "been"), + intercept(2, "there"), + intercept(3, "done"), + intercept(4, "that"), + ), + ) + expected = []string{ + "seen it", + "been", + "there", + "done", + "that", + } + message = strings.Repeat("a", 16) + reply = strings.Repeat(message, 2) + ) + + defer listener.Close() + defer cleanup() + + registerTestingService(server, testImpl) + + go server.Serve(ctx, listener) + defer server.Shutdown(ctx) + + request := &internal.TestPayload{ + Foo: message, + } + response := &internal.TestPayload{} + if err := client.Call(ctx, serviceName, "Test", request, response); err != nil { + t.Fatalf("unexpected error: %v", err) + } + + if !reflect.DeepEqual(recorded, expected) { + t.Fatalf("unexpected ttrpc chained client unary interceptor order (%s != %s)", + strings.Join(recorded, " "), strings.Join(expected, " ")) + } + + if response.Foo != reply { + t.Fatalf("unexpected test service reply: %q != %q", response.Foo, reply) + } +}