Go http net implementation (#164)

Go HTTP initial implementation

Author: Thiyagu55

.gitignore

@@ -1,2 +1,3 @@
 php/sqlcommenter-php/packages/sqlcommenter-laravel/vendor/*
-.idea/**
+.idea/**
+.DS_Store

go/net/http/README.md

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+# http-net  [In development]
+
+SQLcommenter is a plugin/middleware/wrapper to augment application related information/tags with SQL Statements that can be used later to correlate user code with SQL statements.
+
+## Installation
+
+### Install from source
+
+* Clone the source
+* In terminal go inside the client folder location where we need to import sqlcommenter http/net module and enter the below commands
+
+```shell
+go mod edit -replace google.com/sqlcommenter=path/to/google/sqlcommenter/http-net
+
+go mod tiny
+
+go get google.com/sqlcommenter/http-net
+```
+### Install from github [To be added]
+
+## Usage
+
+Please use the sqlcommenter's default go-sql database driver to execute statements. \
+Due to inherent nature of Go, the safer way to pass information from framework to database driver is via `context`. So, it is recommended to use the context based methods of `DB` interface like `QueryContext`, `ExecContext` and `PrepareContext`. 
+
+```go
+db, err := gosql.Open("<driver>", "<connectionString>", sqlcommenter.CommenterOptions{<tag>:<bool>})
+```
+
+### Configuration
+
+Users are given control over what tags they want to append by using `core.CommenterOptions` struct.
+
+```go
+type CommenterOptions struct {
+	EnableDBDriver    bool
+	EnableTraceparent bool  // OpenTelemetry trace information
+	EnableRoute       bool  // applicable for web frameworks
+	EnableFramework   bool  // applicable for web frameworks
+	EnableController  bool  // applicable for web frameworks
+	EnableAction      bool  // applicable for web frameworks
+	}
+```
+
+
+#### Note
+* We only support the `database/sql` driver and have provided an implementation for that.
+* <b>ORM related tags are added to the driver only when the tags are enabled in the commenter's driver's config and also the request context should passed to the querying functions</b>
+* <b>The middleware implementing this sqlcommenter http-net module should be added at the last</b>
+  
+#### Example
+```go
+// middleware is used to intercept incoming HTTP calls and populate request context with commenter tags.
+func middleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+	ctx := httpnet.NewHttpNet(r, next).AddTags(r.Context())
+	next.ServeHTTP(w, r.WithContext(ctx))
+	})
+}
+```
+
+## Options
+
+With Go SqlCommenter, we have configuration to choose which tags to be appended to the comment.
+
+| Options         | Included by default? | net/http                                                                                                                                                                     |
+| --------------- | -------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
+| `Action`        |                      | [net/http handle](https://pkg.go.dev/net/http#Handle)                                                                                                                        |
+| `Route`         |                      | [net/http routing path](https://pkg.go.dev/github.com/gorilla/mux#Route.URLPath)                                                                                             |
+| `Framework`     |                      | [net/http](https://pkg.go.dev/net/http)                                                                                                                                      |
+| `Opentelemetry` |                      | [W3C TraceContext.Traceparent](https://www.w3.org/TR/trace-context/#traceparent-field), [W3C TraceContext.Tracestate](https://www.w3.org/TR/trace-context/#tracestate-field) |

go/net/http/go.mod

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+module github.com/google/sqlcommenter/go/net/http
+
+go 1.19
+
+require github.com/google/sqlcommenter/go/core v0.0.1-beta
+
+require (
+	go.opentelemetry.io/otel v1.10.0 // indirect
+	go.opentelemetry.io/otel/trace v1.10.0 // indirect
+)

go/net/http/go.sum

@@ -0,0 +1,13 @@
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
+github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
+github.com/go-logr/stdr v1.2.2 h1:hSWxHoqTgW2S2qGc0LTAI563KZ5YKYRhT3MFKZMbjag=
+github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
+github.com/google/sqlcommenter/go/core v0.0.1-beta h1:IVszEHanWVeS7UcmP8C3SHa57CmfeqMBj0QUcJ8VZ9Q=
+github.com/google/sqlcommenter/go/core v0.0.1-beta/go.mod h1:CZfcqmbIxngExnZ7Se6AsKNVubZhKyi54aeDJZiqTMQ=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
+github.com/stretchr/testify v1.7.1 h1:5TQK59W5E3v0r2duFAb7P95B6hEeOyEnHRa8MjYSMTY=
+go.opentelemetry.io/otel v1.10.0 h1:Y7DTJMR6zs1xkS/upamJYk0SxxN4C9AqRd77jmZnyY4=
+go.opentelemetry.io/otel v1.10.0/go.mod h1:NbvWjCthWHKBEUMpf0/v8ZRZlni86PpGFEMA9pnQSnQ=
+go.opentelemetry.io/otel/trace v1.10.0 h1:npQMbR8o7mum8uF95yFbOEJffhs1sbCOfDh8zAJiH5E=
+go.opentelemetry.io/otel/trace v1.10.0/go.mod h1:Sij3YYczqAdz+EhmGhE6TpTxUO5/F/AzrK+kxfGqySM=
+gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=

go/net/http/http.go

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+// Copyright 2022 Google LLC
+//
+// 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 http
+
+import (
+	"net/http"
+
+	"github.com/google/sqlcommenter/go/core"
+)
+
+type HTTPRequestExtractor struct {
+	r    *http.Request
+	next any
+}
+
+func NewHTTPRequestExtractor(r *http.Request, next any) *HTTPRequestExtractor {
+	return &HTTPRequestExtractor{r, next}
+}
+
+func (h *HTTPRequestExtractor) Route() string {
+	return h.r.URL.Path
+}
+
+func (h *HTTPRequestExtractor) Action() string {
+	return core.GetFunctionName(h.next)
+}
+
+func (h *HTTPRequestExtractor) Framework() string {
+	return "net/http"
+}