[OSSCA] LoxiLB 1주차: yaml, swagger, cmd, api

2024 오픈소스 컨트리뷰션 아카데미 [체험형-2차] LoxiLB 로드밸런서 에 참여하여
공부하며 정리한 게시글입니다. 

게시글 상 소스코드, 사진에서 **굵게** '''코드쉘''' 에 대한 부분이 들어가있을수도 있습니다.

 

 

LoxiLB 구성

• Management Plane: loxicmd, kube-loxilb
• Control Plane: API server , LoxiNLP, goBGP, netlink
• Data Plane: eBPF

 

Yaml 문법 설명

apiVersion: v1 
kind: Pod 
metadata:
 name: nginx
spec:
 containers:
 - name: nginx
   image: nginx:1.14.2
   ports:
   - containerPort: 80

• Map
  • Key, value, 공백 의 조합으로 구성 key: value
  • value 가 Map 일 경우

key:
 key2: value2

 

• Array
  • value 가 여러개인경우

key:
 - value1
 - value2

 

 

Swagger

LoxiLB 에서 swagger 를 채택 한 이유?

→ swagger 문서 1개만으로도 여러개의 파일을 관리할 수 있다.

 

swagger예시: swagger.yaml

swagger: '2.0'
info:
  title: Company Rest API
  description: Company REST API for Baremetal Scenarios
  version: 0.0.1
schemes:
  - http
#  - https
host: "0.0.0.0:11111"
basePath: /company_name/v1
produces:
  - application/json
consumes:
  - application/json
paths:
#----------------------------------------------
# Account
#----------------------------------------------
  '/account':
    post:
      summary: Create a new account service한글도 되긴함 
      description: Create a new account with...
      parameters:
        - name: attr
          in: body
          required: true
          description: Attributes for load balance service
          schema:
            $ref: '#/definitions/AccountEntry'
      responses:
        '200':
          description: OK
          schema:
            $ref: '#/definitions/PostSuccess'
        '400':
          description: Malformed arguments for API call
          schema:
            $ref: '#/definitions/Error'
  '/account/all':
    get:
      summary: Get all of user
      description: Get all of the user infomation.
      responses:
        '200':
          description: OK
          schema:
            type: object
            properties:
              Attr:
                type: array
                items:
                  $ref: '#/definitions/AccountEntry'
        '401':
          description: Invalid authentication credentials
          schema:
            $ref: '#/definitions/Error'
        '500':
          description: Internal service error
          schema:
            $ref: '#/definitions/Error'
        '503':
          description: Maintanence mode
          schema:
            $ref: '#/definitions/Error'
  '/account/{user_id}':
    delete:
      summary: Delete one user
      description: Delete one user.
      parameters:
        - name: user_id
          in: path
          type: string
          required: true
          description: user id
      responses:
        '204':
          description: OK
        '400':
          description: Malformed arguments for API call
          schema:
            $ref: '#/definitions/Error'
#----------------------------------------------
# Schema definitions
#----------------------------------------------
definitions:
  Error:
    type: object
    properties:
      code:
        type: integer
        format: int32
      sub-code:
        type: integer
        format: int32
      message:
        type: string
      fields:
        type: array
        items:
          type: string
      details:
        type: string    

  AccountEntry:
    type: object
    properties:
      user_id:
        type: string
      password:
        type: string
      email:
        type: string

  PostSuccess:
    type: object
    properties:
      code:
        type: integer
      message:
        type: string

 

go mod

go mod init swaggertest

 

swagger 기반 환경 구성

sudo docker run --rm -it  --user $(id -u):$(id -g) -e GOPATH=$(go env GOPATH):/go -v $HOME:$HOME -w $(pwd) quay.io/goswagger/swagger:0.30.3 generate server

 

환경 구성 진행

go mod tidy

~/ossca/examples/api ❯ tree .                                                                      anaconda3 13:16:47
.
├── cmd
│   └── company-rest-api-server
**│       └── main.go**
├── go.mod
├── go.sum
├── models
│   ├── account_entry.go
│   ├── error.go
│   └── post_success.go
├── restapi
│   ├── configure_company_rest_api.go
│   ├── doc.go
│   ├── embedded_spec.go
│   ├── operations
│   │   ├── company_rest_api_api.go
│   │   ├── delete_account_user_id.go
│   │   ├── delete_account_user_id_parameters.go
│   │   ├── delete_account_user_id_responses.go
│   │   ├── delete_account_user_id_urlbuilder.go
│   │   ├── get_account_all.go
│   │   ├── get_account_all_parameters.go
│   │   ├── get_account_all_responses.go
│   │   ├── get_account_all_urlbuilder.go
│   │   ├── post_account.go
│   │   ├── post_account_parameters.go
│   │   ├── post_account_responses.go
│   │   └── post_account_urlbuilder.go
│   └── server.go
└── swagger.yaml

 

 

go build

go build cmd/company-rest-api-server/main.go

~/ossca/examples/api ❯ tree .                                                                    3s  anaconda3 13:17:23
.
├── cmd
│   └── company-rest-api-server
**│       └── main.go**
├── go.mod
├── go.sum
**├── main**
├── models
│   ├── account_entry.go
│   ├── error.go
│   └── post_success.go
├── restapi
│   ├── configure_company_rest_api.go
│   ├── doc.go
│   ├── embedded_spec.go
│   ├── operations
│   │   ├── company_rest_api_api.go
│   │   ├── delete_account_user_id.go
│   │   ├── delete_account_user_id_parameters.go
│   │   ├── delete_account_user_id_responses.go
│   │   ├── delete_account_user_id_urlbuilder.go
│   │   ├── get_account_all.go
│   │   ├── get_account_all_parameters.go
│   │   ├── get_account_all_responses.go
│   │   ├── get_account_all_urlbuilder.go
│   │   ├── post_account.go
│   │   ├── post_account_parameters.go
│   │   ├── post_account_responses.go
│   │   └── post_account_urlbuilder.go
│   └── server.go
└── swagger.yaml

 

 

 

api test

restapi/configure_company_rest_api.go

...

    api.JSONConsumer = runtime.JSONConsumer()

    api.JSONProducer = runtime.JSONProducer()

    if api.DeleteAccountUserIDHandler == nil {
        api.DeleteAccountUserIDHandler = operations.DeleteAccountUserIDHandlerFunc(func(params operations.DeleteAccountUserIDParams) middleware.Responder {
            return middleware.NotImplemented("operation operations.DeleteAccountUserID has not yet been implemented")
        })
    }
    if api.GetAccountAllHandler == nil {
        api.GetAccountAllHandler = operations.GetAccountAllHandlerFunc(func(params operations.GetAccountAllParams) middleware.Responder {
            return middleware.NotImplemented("operation operations.GetAccountAll has not yet been implemented")
        })
    }
    if api.PostAccountHandler == nil {
        api.PostAccountHandler = operations.PostAccountHandlerFunc(func(params operations.PostAccountParams) middleware.Responder {
            return middleware.NotImplemented("operation operations.PostAccount has not yet been implemented")
        })
    }

...

현재 Delete, Get, Post 에 대하여 코드선언은 되었지만, 실제 작동은 정의되지않은 상태

→ 따라서 GET 메소드를 날리면 "operation GetAccountAll has not yet been implemented” 를 응답받았음

 

 

 

handler 생성

mkdir restapi/handler

restapi/handler/account.go

package handler

import (
    "swaggertest/models"
    "swaggertest/restapi/operations"

    "github.com/go-openapi/runtime/middleware"
)

func ConfigGetAccount(params operations.GetAccountAllParams) middleware.Responder {
    var result []*models.AccountEntry
    result = make([]*models.AccountEntry, 0)
    result = append(result, &models.AccountEntry{
        UserID:   "idid",
        Password: "passwords",
        Email:    "test@test.io",
    })
    return operations.NewGetAccountAllOK().WithPayload(&operations.GetAccountAllOKBody{Attr: result})
}

 

 

restapi/configure_company_rest_api.go 수정

    if api.DeleteAccountUserIDHandler == nil {
        api.DeleteAccountUserIDHandler = operations.DeleteAccountUserIDHandlerFunc(func(params operations.DeleteAccountUserIDParams) middleware.Responder {
            return middleware.NotImplemented("operation operations.DeleteAccountUserID has not yet been implemented")
        })
    }
    **api.GetAccountAllHandler = operations.GetAccountAllHandlerFunc(handler.ConfigGetAccount)**

    if api.PostAccountHandler == nil {
        api.PostAccountHandler = operations.PostAccountHandlerFunc(func(params operations.PostAccountParams) middleware.Responder {
            return middleware.NotImplemented("operation operations.PostAccount has not yet been implemented")
        })
    }

 

다시 빌드 이후 실행

go build cmd/company-rest-api-server/main.go

curl -X 'GET' \
  'http://0.0.0.0:11111/company_name/v1/account/all' \
  -H 'accept: application/json'

참고로 이렇게 띄운 서버는 swagger 페이지도 뜨는데

경로는 swagger.yaml 파일에 있는

host: "0.0.0.0:11111"
basePath: /company_name/v1

를 참고해서

http://localhost:11111/company_name/v1/docs 로 접근가능하다

 

 

COBRA

Golang 기반으로 CLI 를 만드는 라이브러리

• K8s 에서 사용하기때문에, 통일성을 위해 loxilb 에서도 채택함

 

Command 코드 구조분석

cmd/root.go

var (
    rootCmd = &cobra.Command{
        Use:   "cobra-cli",
        Short: "A generator for Cobra based Applications",
        Long: `Cobra is a CLI library for Go that empowers applications.
This application is a tool to generate the needed files
to quickly create a Cobra application.`,
    }
)

...

func init() {
    restOptions := &api.RESTOptions{}

    rootCmd.PersistentFlags().Int16VarP(&restOptions.Timeout, "timeout", "t", 10, "Set timeout")
    rootCmd.PersistentFlags().StringVarP(&restOptions.Protocol, "protocol", "", "http", "Set API server http/https")
    rootCmd.PersistentFlags().StringVarP(&restOptions.PrintOption, "output", "o", "", "Set output layer (ex.) wide, json)")
    rootCmd.PersistentFlags().StringVarP(&restOptions.ServerIP, "apiserver", "s", "127.0.0.1", "Set API server IP address")
    rootCmd.PersistentFlags().Int16VarP(&restOptions.ServerPort, "port", "p", 11111, "Set API server port number")

    rootCmd.AddCommand(create.CreateCmd())
    rootCmd.AddCommand(get.GetCmd(restOptions))

}

...

CLI 로 입력할때에 사용할 옵션을 정의하는 소스코드

root.go 에서는 주로 사용할 옵션을 정의함

 

cmd/get/get.go

...

func GetCmd(restOptions *api.RESTOptions) *cobra.Command {
    //func GetCmd() *cobra.Command {
    var getCmd = &cobra.Command{
        Use:   "get",
        Short: "get a Load balance features in the LoxiLB.",
        Long: `get a Load balance features in the LoxiLB.
Create - Service type external load-balancer, Vlan, Vxlan, Qos Policies, 
     Endpoint client,FDB, IPaddress, Neighbor, Route,Firewall, Mirror, Session, UlCl
`,
        Run: func(cmd *cobra.Command, args []string) {
            fmt.Printf("get called!\n", args)
        },
    }

    getCmd.AddCommand(NewGetAccountCmd(restOptions))
    return getCmd
}

...

이런식으로 메소드 내부에서도 정의

 

 

Command - API 연동

tree .
.
**├── api
│   ├── account.go
│   ├── client.go
│   ├── common.go
│   └── rest.go**
├── clitest
**├── cmd
│   ├── create
│   │   └── create.go
│   ├── get
│   │   ├── get.go
│   │   └── get_account.go
│   ├── root.go
│   └── version.go**
├── go.mod
├── go.sum
└── main.go

5 directories, 13 files

• api : API호출을 위한 코드 모음
• api/rest.go: CRUD rest api 호출에 대한 부분(Get, Post, …)
• api/common.go: REST 를 command 로 호출(Create, Delete …)
• api/client.go: 특정 API 를 정의하는 부분
• api/account.go, cmd/get/get_account.go: 실제 Account 에 호출을 날리는 부분