Support go-micro framework with v4 version (#46)

Author: mrproliu

.github/workflows/plugin-tests.yaml

@@ -62,6 +62,7 @@ jobs:
           - go-restfulv3
           - gorm
           - kratosv2
+          - microv4
           - plugin_exclusion
     steps:
       - uses: actions/checkout@v2

agent/core/compile.go

@@ -34,6 +34,7 @@ import (
 	_ "sync"
 	_ "sync/atomic"
 	_ "time"
+	_ "unsafe"
 
 	//go:nolint
 	_ "github.com/apache/skywalking-go/agent/core/operator"

docs/en/agent/support-plugins.md

@@ -9,6 +9,7 @@
 * RPC Frameworks
   * `dubbo`: [Dubbo](https://github.com/apache/dubbo-go)
   * `kratosv2`: [Kratos](github.com/go-kratos/kratos)
+  * `microv4`: [Go-Micro](https://github.com/go-micro/go-micro)
 * Database Client
   * `gorm`: [GORM](https://github.com/go-gorm/gorm)
     * [MySQL Driver](https://github.com/go-gorm/mysql)

docs/en/development-and-contribution/development-guide.md

@@ -387,6 +387,26 @@ Following the previous API define, you should following these steps to use the a
 4. Once the above steps are all set, call `span.AsyncFinish()` in any goroutine.
 5. When the `span.AsyncFinish()` is complete for all spans, the all spans would be finished and report to the backend.
 
+#### Tracing Context Operation
+
+In the Go Agent, Trace Context would continue cross goroutines automatically by default.
+However, in some cases, goroutine would be context sharing due to be scheduled by the pool mechanism. Consider these advanced APIs to manipulate context and switch the current context.
+
+```go
+// CaptureContext capture current tracing context in the current goroutine.
+func CaptureContext() ContextSnapshot
+
+// ContinueContext continue the tracing context in the current goroutine.
+func ContinueContext(ctx ContextSnapshot)
+
+// CleanContext clean the tracing context in the current goroutine.
+func CleanContext()
+```
+
+Typically, use APIs as following to control or switch the context:
+1. Use `tracing.CaptureContext()` to get the ContextSnapshot object.
+2. Propagate the snapshot context to any other goroutine in your plugin.
+3. Use `tracing.ContinueContext(snapshot)` to continue the snapshot context in the target goroutine.
 
 ## Import Plugin
 

go.work

@@ -11,6 +11,7 @@ use (
 	./plugins/go-restfulv3
 	./plugins/gorm
 	./plugins/kratosv2
+	./plugins/microv4
 
 	./test/benchmark-codebase/consumer
 	./test/benchmark-codebase/provider
@@ -24,6 +25,7 @@ use (
 	./test/plugins/scenarios/go-restfulv3
 	./test/plugins/scenarios/gorm
 	./test/plugins/scenarios/kratosv2
+	./test/plugins/scenarios/microv4
 
 	./test/plugins/scenarios/plugin_exclusion
 

go.work.sum

@@ -16,7 +16,7 @@ require (
 	github.com/golang/protobuf v1.5.3 // indirect
 	github.com/kr/pretty v0.3.0 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
-	github.com/rogpeppe/go-internal v1.9.0 // indirect
+	github.com/rogpeppe/go-internal v1.10.0 // indirect
 	golang.org/x/mod v0.9.0 // indirect
 	golang.org/x/net v0.10.0 // indirect
 	golang.org/x/sys v0.8.0 // indirect

plugins/core/go.mod

@@ -68,7 +68,7 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/rogpeppe/fastuuid v1.2.0/go.mod h1:jVj6XXZzXRy/MSR5jhDC/2q6DgLz+nrA6LYCDYWNEvQ=
 github.com/rogpeppe/go-internal v1.6.1/go.mod h1:xXDCJY+GAPziupqXw64V24skbSoqbTEfhy4qGm1nDQc=
-github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
+github.com/rogpeppe/go-internal v1.10.0 h1:TMyTOH3F/DB16zRVcYyreMH6GnZZrwQVAoYjRBZyWFQ=
 github.com/sergi/go-diff v1.2.0 h1:XU+rvMAioB0UC3q1MFrIQy4Vo5/4VsRDQQXHsEya6xQ=
 github.com/spaolacci/murmur3 v0.0.0-20180118202830-f09979ecbc72/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=

plugins/core/go.sum

@@ -22,6 +22,7 @@ var GetOperator = func() Operator { return nil }
 type Operator interface {
 	Tracing() interface{} // to TracingOperator
 	Logger() interface{}  // to LogOperator
+	Tools() interface{}   // to ToolsOperator
 	DebugStack() []byte   // Getting the stack of the current goroutine, for getting details when plugin broken.
 	Entity() interface{}  // Get the entity of the service
 }

plugins/core/operator/common.go

@@ -0,0 +1,22 @@
+// Licensed to Apache Software Foundation (ASF) under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Apache Software Foundation (ASF) licenses this file to you 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 operator
+
+type ToolsOperator interface {
+	ReflectGetValue(instance interface{}, filters []interface{}) interface{}
+}