chore: Refactor PDF conversion handler and update Dockerfile and environment configurations

Author: yannick2009

.dockerignore

@@ -2,5 +2,5 @@ example.env
 .git
 .gitignore
 
-images/
+img/
 pdf/

.env.example

@@ -1,9 +1,10 @@
+# SERVER
 GIN_MODE=release
 IMAGE_STORAGE_PATH=/path/to/image/storage
 PDF_STORAGE_PATH=/path/to/pdf/storage
+PORT=8080
 
-# SERVER
-
+# SERVICE
 SERVER_SERVICE_PORT=8000
 SERVER_SERVICE="localhost" # SERVICE NAME
 SERVER_SERVICE_ORIGIN="http://${SERVER_SERVICE}:${SERVER_SERVICE_PORT}"

.github/workflows/default.yml

@@ -12,21 +12,21 @@ jobs:
       - name: Checkout the repository
         uses: actions/checkout@v4
 
-      - name: executing remote ssh commands using password
-        uses: appleboy/ssh-action@v1.0.3
-        with:
-          host: ${{ secrets.SSH_HOST }}
-          username: root
-          password: ${{ secrets.SSH_PASSWORD }}
-          script: |
-            whoami
-            cd /critik-v
-            rm -rf ./${{github.event.repository.name}}
-            git clone https://github.com/${{github.repository}}.git
-            cd ./${{github.event.repository.name}}
-            cp .env.example .env
-            sed -i "s/GIN_MODE=.*$/GIN_MODE=production/" .env
-            sed -i "s/IMAGE_STORAGE_PATH=.*$/IMAGE_STORAGE_PATH=images/" .env
-            sed -i "s/PDF_STORAGE_PATH=.*$/PDF_STORAGE_PATH=pdf/" .env
-            sed -i "s/SERVER_SERVICE_PORT=.*$/SERVER_SERVICE_PORT=${{secrets.SERVER_PORT}}/" .env
-            sed -i "s/SERVER_SERVICE=.*$/SERVER_SERVICE=${{secrets.SERVER_SERVICE}}/" .env
+      # - name: executing remote ssh commands using password
+      #   uses: appleboy/ssh-action@v1.0.3
+      #   with:
+      #     host: ${{ secrets.SSH_HOST }}
+      #     username: root
+      #     password: ${{ secrets.SSH_PASSWORD }}
+      #     script: |
+      #       whoami
+      #       cd /critik-v
+      #       rm -rf ./${{github.event.repository.name}}
+      #       git clone https://github.com/${{github.repository}}.git
+      #       cd ./${{github.event.repository.name}}
+      #       cp .env.example .env
+      #       sed -i "s/GIN_MODE=.*$/GIN_MODE=production/" .env
+      #       sed -i "s/IMAGE_STORAGE_PATH=.*$/IMAGE_STORAGE_PATH=images/" .env
+      #       sed -i "s/PDF_STORAGE_PATH=.*$/PDF_STORAGE_PATH=pdf/" .env
+      #       sed -i "s/SERVER_SERVICE_PORT=.*$/SERVER_SERVICE_PORT=${{secrets.SERVER_PORT}}/" .env
+      #       sed -i "s/SERVER_SERVICE=.*$/SERVER_SERVICE=${{secrets.SERVER_SERVICE}}/" .env

.gitignore

@@ -8,4 +8,4 @@
 .vscode/
 .idea/
 
-images/
+img/

dockerfile

@@ -3,9 +3,7 @@ FROM golang:1.22 AS builder
 WORKDIR /builder
 
 COPY go.mod .
-
 COPY go.sum .
-
 RUN go mod download
 
 RUN apt-get update && apt-get install -y libmupdf-dev
@@ -14,7 +12,7 @@ COPY . .
 
 RUN go build -o /main .
 
-FROM ubuntu:latest
+FROM debian:bullseye-slim
 
 EXPOSE 5001
 

handlers/convertPdf.go renamed to handlers/pdf.go

@@ -9,16 +9,23 @@ import (
 	"github.com/gin-gonic/gin"
 )
 
+// body represents the request body
 type body struct {
 	FileName string `json:"filename"`
 }
 
-func ConvertPdf(ctx *gin.Context) {
+// ConvertPdf converts a PDF file to a JPEG image
+func POSTConvertPdf(ctx *gin.Context) {
 	var body body
-	finished := make(chan bool)
-	mutex := &sync.Mutex{}
 
+	// Create a mutex to lock the goroutine
+	mutex := &sync.Mutex{}
 	mutex.Lock()
+	
+	// Create a channel to notify when the goroutine is finished
+	finished := make(chan bool)
+	
+	// Convert the PDF to JPEG in a goroutine
 	go func() {
 		defer mutex.Unlock()
 		err := ctx.BindJSON(&body)

main.go

@@ -2,45 +2,44 @@ package main
 
 import (
 	"go-pdf2jpeg/handlers"
+	"go-pdf2jpeg/utils"
 	"log"
-	"os"
 
 	"github.com/gin-contrib/cors"
 	"github.com/gin-gonic/gin"
 	"github.com/joho/godotenv"
 )
 
-const serverPort string = ":5001"
+const envFile = ".env" // Name of the .env file
 
 func init() {
 	// Load .env file
-	err := godotenv.Load(".env")
+	err := godotenv.Load(envFile)
 	if err != nil {
-		log.Fatalf("Error loading .env file: %s", err)
+		log.Fatal(err)
 	}
 }
 
 func main() {
-	if os.Getenv("GIN_MODE") == "production" {
+	// Set Gin mode to release if the application is running in production mode
+	if prodMode := utils.IsProduction(); prodMode {
 		gin.SetMode(gin.ReleaseMode)
 	}
+
+	// Create server instance
 	server := gin.Default()
 
-	// Middleware
-	var serverOrigin string = os.Getenv("SERVER_SERVICE_ORIGIN")
-	if serverOrigin == "" {
-		serverOrigin = "*"
-	}
+	// CORS middleware configuration to allow only POST requests from the specified origin
 	server.Use(cors.New(cors.Config{
-		AllowOrigins:     []string{serverOrigin},
+		AllowOrigins:     []string{utils.GetCorsOrigin()},
 		AllowMethods:     []string{"POST"},
 		AllowHeaders:     []string{"Origin"},
 		AllowCredentials: true,
 	}))
 
 	// Routes
-	server.POST("/convert", handlers.ConvertPdf)
+	server.POST("/convert", handlers.POSTConvertPdf)
 
 	// Run server
-	server.Run(serverPort)
+	server.Run(utils.GetPort())
 }

pdf/test-0.pdf

@@ -0,0 +1,92 @@
+package service
+
+import (
+	"errors"
+	"fmt"
+	"go-pdf2jpeg/utils"
+	"image/jpeg"
+	"os"
+	"path/filepath"
+
+	"github.com/gen2brain/go-fitz"
+)
+
+const jpegQuality int = 7    // Quality of the JPEG image
+const imgExt string = ".jpg" // Extension of
+const docExt string = ".pdf" // Extension of the document
+
+var (
+	ErrPickingPage    = errors.New("error picking page")              // Error when picking the first page of the PDF
+	ErrCreatingJpeg   = errors.New("error creating jpeg image")       // Error when creating the jpeg image
+	ErrEncodingJpeg   = errors.New("error encoding jpeg image")       // Error when encoding the jpeg image
+	ErrPdfDirNotExist = errors.New("pdf directory does not exist")    // Error when the pdf directory does not exist
+	ErrImgDirCreation = errors.New("image directory creation failed") // Error when the image directory creation fails
+)
+
+/*
+outPutFileName returns the name of the output file
+by appending the image extension to the fileName
+*/
+func outPutFileName(fileName string) string {
+	return fmt.Sprintf("%v%v", fileName, imgExt)
+}
+
+/*
+pdfPath returns the path to the PDF file
+by appending the document extension to the fileName
+*/
+func pdfPath(dir, fileName string) string {
+	return fmt.Sprintf("%v/%v%v", dir, fileName, docExt)
+}
+
+/*
+convert converts the first page of the PDF to a JPEG image
+and saves it in the imgDir directory
+*/
+func convert(doc *fitz.Document, imgDir string, fileName string) error {
+	img, err := doc.Image(0)
+	if err != nil {
+		return errors.Join(ErrPickingPage, err)
+	}
+
+	// Create a new file in the img directory
+	f, err := os.Create(filepath.Join(imgDir, outPutFileName(fileName)))
+	if err != nil {
+		return errors.Join(ErrCreatingJpeg, err)
+	}
+	defer f.Close()
+
+	// Encode the image to JPEG
+	err = jpeg.Encode(f, img, &jpeg.Options{Quality: int(jpegQuality)})
+	if err != nil {
+		return errors.Join(ErrEncodingJpeg, err)
+	}
+	return nil
+}
+
+/**
+* PdfToJpeg converts the first page of the PDF to a JPEG image
+* and saves it in the img directory
+ */
+func PdfToJpeg(fileName string) error {
+	pdfDir := utils.GetPdfDir() // Path to the directory where the PDFs are stored
+	imgDir := utils.GetImgDir() // Path to the directory where the images will be stored
+
+	doc, err := fitz.New(pdfPath(pdfDir, fileName))
+	if err != nil {
+		return errors.Join(ErrPdfDirNotExist, err)
+	}
+	defer doc.Close()
+
+	// Check if the img directory exists
+	if _, err := os.Stat(imgDir); os.IsNotExist(err) {
+		// img directory does not exist
+		err = os.Mkdir(imgDir, os.ModePerm)
+		if err != nil {
+			return errors.Join(ErrImgDirCreation, err)
+		}
+		return convert(doc, imgDir, fileName)
+	}
+	// img directory already exists
+	return convert(doc, imgDir, fileName)
+}

pdf/test-1.pdf

@@ -0,0 +1,43 @@
+package utils
+
+import "os"
+
+const defaultPdfDir = "pdf" // Default directory where the PDFs are stored
+const defaultImgDir = "img" // Default directory where the images will be stored
+
+// IsProduction returns true if the application is running in production mode
+func IsProduction() bool {
+	return os.Getenv("GIN_MODE") == "production"
+}
+
+// GetPort returns the port where the server will be running
+func GetPort() string {
+	return ":5001"
+}
+
+// GetPdfDir returns the path to the directory where the PDFs are stored
+func GetPdfDir() string {
+	name := os.Getenv("PDF_STORAGE_PATH")
+	if name == "" {
+		return defaultPdfDir
+	}
+	return name
+}
+
+// GetImgDir returns the path to the directory where the images will be stored
+func GetImgDir() string {
+	name := os.Getenv("IMAGE_STORAGE_PATH")
+	if name == "" {
+		return defaultImgDir
+	}
+	return name
+}
+
+// GetCorsOrigin returns the origin to be allowed by the CORS middleware
+func GetCorsOrigin() string {
+	origin := os.Getenv("SERVER_SERVICE_ORIGIN")
+	if origin == "" {
+		return "*"
+	}
+	return origin
+}