feat: add the core project design

README.md

@@ -1,5 +1,20 @@
 # howmuch
 
+<!--toc:start-->
+- [howmuch](#howmuch)
+  - [Project Diary](#project-diary)
+    - [2024/09/30](#20240930)
+    - [2024/10/01](#20241001)
+      - [Config](#config)
+      - [Business logic](#business-logic)
+      - [Startup framework](#startup-framework)
+    - [2024/10/02](#20241002)
+      - [Logging](#logging)
+      - [Version](#version)
+    - [2024/10/03](#20241003)
+    - [2024/10/04](#20241004)
+<!--toc:end-->
+
 A tricount like expense-sharing system written in Go
 
 ---
@@ -99,7 +114,7 @@ consumer queue, etc.
 #### Startup framework
 
 When business logic becomes complicated, we cannot spread them into a simple
-`main` function. We need something to handle all thoses task, sync or async.
+`main` function. We need something to handle all those task, sync or async.
 That is why we use `cobra`.
 
 So for this project, we will use the combination of `pflag`, `viper` and
@@ -124,3 +139,59 @@ Set up the web server with some necessary/nice to have middlewares.
 - Recovery, Logger (already included in Default mode)
 - CORS
 - RequestId
+
+Using channel and signal to gracefully shutdown the server.
+
+A more comprehensible error code design :
+
+- Classical HTTP code.
+- Service error code composed by "PlatformError.ServiceError", e.g. "ResourceNotFound.PageNotFound"
+- error message.
+
+The service error code helps to identify the problem more precisely.
+
+### 2024/10/04
+
+Application architecture design follows [Clean Architecture](https://manakuro.medium.com/clean-architecture-with-go-bce409427d31)
+that has several layers:
+
+- Entities: the models of the product
+- Use cases: the core business rule
+- Interface Adapters: convert data-in to entities and convert data-out to
+output ports.
+- Frameworks and drivers: Web server, DB.
+
+Based on this logic, we create the following directories:
+
+- `model`: entities
+- `infra`: Provides the necessary functions to setup the infrastructure,
+especially the DB (output-port), but also the router (input-port). Once
+setup, we don't touch them anymore.
+- `registry`: Provides a register function for the main to register a service.
+It takes the pass to the output-port (ex.DBs) and gives back a pass
+(controller) to the input-port
+- `adapter`: Controllers are one of the adapters, when they are called,
+they parse the user input and parse them into models and run the usecase
+rules. Then they send back the response(input-port). For the output-port
+part, the `repo` is the implementation of interfaces defined in `usecase/repo`.
+- `usecase`: with the input of adapter, do what have to be done, and answer
+with the result. In the meantime, we may have to store things into DBs.
+Here we use the Repository model to decouple the implementation of the repo
+with the interface. Thus in `usecase/repo` we only define interfaces.
+
+Then it comes the real design for the app.
+
+Following the Agile method, I don't try to define the entire project at the
+beginning but step by step, starting at the user part.
+
+```go
+type User struct {
+	CreatedAt   time.Time
+	UpdatedAt   time.Time
+	FirstName   string
+	LastName    string
+	Email       string
+	Password    string
+	ID          int
+}
+```

configs/howmuch.yml

@@ -22,7 +22,9 @@
 
 dev-mode: true
 
+web:
   addr: :8080
+  shutdown-timeout: 10
 
 db:
   # DB host

go.mod

@@ -4,6 +4,7 @@ go 1.23.1
 
 require (
 	github.com/fsnotify/fsnotify v1.7.0
+	github.com/gin-contrib/cors v1.7.2
 	github.com/gin-gonic/gin v1.10.0
 	github.com/google/uuid v1.6.0
 	github.com/gosuri/uitable v0.0.4
@@ -12,6 +13,7 @@ require (
 	github.com/spf13/viper v1.19.0
 	github.com/stretchr/testify v1.9.0
 	go.uber.org/zap v1.27.0
+	golang.org/x/net v0.25.0
 )
 
 require (
@@ -54,7 +56,6 @@ require (
 	golang.org/x/arch v0.8.0 // indirect
 	golang.org/x/crypto v0.23.0 // indirect
 	golang.org/x/exp v0.0.0-20230905200255-921286631fa9 // indirect
-	golang.org/x/net v0.25.0 // indirect
 	golang.org/x/sys v0.20.0 // indirect
 	golang.org/x/text v0.15.0 // indirect
 	google.golang.org/protobuf v1.34.1 // indirect

go.sum

@@ -19,6 +19,8 @@ github.com/fsnotify/fsnotify v1.7.0 h1:8JEhPFa5W2WU7YfeZzPNqzMP6Lwt7L2715Ggo0nos
 github.com/fsnotify/fsnotify v1.7.0/go.mod h1:40Bi/Hjc2AVfZrqy+aj+yEI+/bRxZnMJyTJwOpGvigM=
 github.com/gabriel-vasile/mimetype v1.4.3 h1:in2uUcidCuFcDKtdcBxlR0rJ1+fsokWf+uqxgUFjbI0=
 github.com/gabriel-vasile/mimetype v1.4.3/go.mod h1:d8uq/6HKRL6CGdk+aubisF/M5GcPfT7nKyLpA0lbSSk=
+github.com/gin-contrib/cors v1.7.2 h1:oLDHxdg8W/XDoN/8zamqk/Drgt4oVZDvaV0YmvVICQw=
+github.com/gin-contrib/cors v1.7.2/go.mod h1:SUJVARKgQ40dmrzgXEVxj2m7Ig1v1qIboQkPDTQ9t2E=
 github.com/gin-contrib/sse v0.1.0 h1:Y/yl/+YNO8GZSjAhjMsSuLt29uWRFHdHYUb5lYOV9qE=
 github.com/gin-contrib/sse v0.1.0/go.mod h1:RHrZQHXnP2xjPF+u1gW/2HnVO7nvIa9PG3Gm+fLHvGI=
 github.com/gin-gonic/gin v1.10.0 h1:nTuyha1TYqgedzytsKYqna+DfLos46nTv2ygFy86HFU=
@@ -141,8 +143,8 @@ golang.org/x/text v0.15.0/go.mod h1:18ZOQIKpY8NJVqYksKHtTdi31H5itFRjB5/qKTNYzSU=
 google.golang.org/protobuf v1.34.1 h1:9ddQBjfCyZPOHPUiPxpYESBLc+T8P3E+Vo4IbKZgFWg=
 google.golang.org/protobuf v1.34.1/go.mod h1:c6P6GXX6sHbq/GpV6MGZEdwhWPcYBgnhAHhKbcUYpos=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15 h1:YR8cESwS4TdDjEe65xsg0ogRM/Nc3DYOhEAlW+xobZo=
-gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/ini.v1 v1.67.0 h1:Dgnx+6+nfE+IfzjUEISNeydPJh9AXNNsWbGP9KzCsOA=
 gopkg.in/ini.v1 v1.67.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

internal/howmuch/howmuch.go

@@ -23,14 +23,24 @@
 package howmuch
 
 import (
+	"errors"
 	"fmt"
 	"net/http"
+	"os"
+	"os/signal"
+	"syscall"
+	"time"
 
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/core"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/errno"
 	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/log"
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/middleware"
 	"git.vinchent.xyz/vinchent/howmuch/pkg/version/verflag"
+	"github.com/gin-contrib/cors"
 	"github.com/gin-gonic/gin"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
+	"golang.org/x/net/context"
 )
 
 var cfgFile string
@@ -96,13 +106,56 @@ func run() error {
 
 	r := gin.Default()
 
+	// Middlewares
+	corsCfg := cors.DefaultConfig()
+	corsCfg.AllowAllOrigins = true
+	corsCfg.AllowHeaders = append(corsCfg.AllowHeaders, "Authorization", "Accept", "X-CSRF-Token")
+	r.Use(cors.New(corsCfg))
+
+	r.Use(middleware.RequestID())
+
+	r.NoRoute(func(ctx *gin.Context) {
+		core.WriteResponse(ctx, errno.PageNotFoundErr, nil)
+	})
+
 	r.GET("/", func(ctx *gin.Context) {
-		ctx.JSON(http.StatusOK, gin.H{
+		// time.Sleep(10 * time.Second) // Test shutdown
+		core.WriteResponse(ctx, nil, gin.H{
 			"message": "how much?",
 		})
 	})
 
-	r.Run(viper.GetString("addr"))
+	server := http.Server{
+		Addr:    viper.GetString("web.addr"),
+		Handler: r,
+	}
+
+	go func() {
+		if err := server.ListenAndServe(); !errors.Is(err, http.ErrServerClosed) {
+			log.FatalLog(err.Error())
+		}
+	}()
+
+	signalChan := make(chan os.Signal, 1)
+
+	signal.Notify(signalChan, syscall.SIGTERM, syscall.SIGINT)
+	<-signalChan
+
+	shutdownTimeout := viper.GetDuration("web.shutdown-timeout")
+	log.DebugLog("Shutdown", "timeout", shutdownTimeout)
+
+	ctx, cancel := context.WithTimeout(
+		context.Background(),
+		shutdownTimeout*time.Second,
+	)
+	defer cancel()
+
+	if err := server.Shutdown(ctx); err != nil {
+		log.ErrorLog("Server forced shutdown", "err", err)
+		return err
+	}
+
+	log.InfoLog("Ciao!")
 
 	return nil
 }

internal/pkg/core/core.go

@@ -0,0 +1,51 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package core
+
+import (
+	"net/http"
+
+	"git.vinchent.xyz/vinchent/howmuch/internal/pkg/errno"
+	"github.com/gin-gonic/gin"
+)
+
+type ErrResponse struct {
+	Code    string `json:"code"`
+	Message string `json:"message"`
+}
+
+// WriteResponse writes the response to the HTTP response writer with HTTP code
+// and potential errors.
+func WriteResponse(c *gin.Context, err error, data any) {
+	// No error, write json response directly
+	if err == nil {
+		c.JSON(http.StatusOK, data)
+		return
+	}
+
+	error := errno.Decode(err)
+	c.JSON(error.HTTP, ErrResponse{
+		Code:    error.Code,
+		Message: error.Message,
+	})
+}

internal/pkg/errno/code.go

@@ -0,0 +1,41 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package errno
+
+import "net/http"
+
+var (
+	OK = &Errno{HTTP: http.StatusOK, Code: "", Message: ""}
+
+	InternalServerErr = &Errno{
+		HTTP:    http.StatusInternalServerError,
+		Code:    "InternalError",
+		Message: "Internal server error",
+	}
+
+	PageNotFoundErr = &Errno{
+		HTTP:    http.StatusNotFound,
+		Code:    "ResourceNotFound.PageNotFound",
+		Message: "Page not found",
+	}
+)

internal/pkg/errno/errno.go

@@ -0,0 +1,51 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
+package errno
+
+type Errno struct {
+	HTTP    int
+	Code    string
+	Message string
+}
+
+// Error implements Error() method in error interface
+func (err *Errno) Error() string {
+	return err.Message
+}
+
+// Decode tries to get the Errno from the error
+func Decode(err error) *Errno {
+	if err == nil {
+		return OK
+	}
+
+	switch typed := err.(type) {
+	case *Errno:
+		return typed
+	default:
+	}
+
+	internErr := InternalServerErr
+	internErr.Message = err.Error()
+	return internErr
+}

internal/pkg/middleware/requestid.go

@@ -1,3 +1,25 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
 package middleware
 
 import (

internal/pkg/middleware/requestid_test.go

@@ -1,3 +1,25 @@
+// MIT License
+//
+// Copyright (c) 2024 vinchent <vinchent@vinchent.xyz>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+
 package middleware
 
 import (