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Navin Kodag
Navin Kodag

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Golang image search api

#gin #go #restapi #imagesearch

Building the REST API

I'll be using gin for this part of project.

Gin is a web framework written in Go (Golang). It features a martini-like API with performance that is up to 40 times faster thanks to httprouter. If you need performance and good productivity, you will love Gin.

TLDR

First we create our go.mod file:

 go mod init Intersect_api
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Then we'll create our main.go file and add the following code.

// main.go package main import ( "Intersect/server" "log" "os" "time" "github.com/getsentry/sentry-go" ) func main() { // Initialize Libraries // Initialize and defer Sentry if err := sentry.Init(sentry.ClientOptions{ Dsn: os.Getenv("SENTRY_DSN"), }); err != nil { log.Fatalln("Sentry Init Error: ", err) } defer sentry.Flush(2 * time.Second) // Initialize Server server.Init() }
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  • Create a server module and initialize the server 
/// server.go package server import "github.com/getsentry/sentry-go" // Init : Initialize the routes and server func Init() { r := NewRouter() err := r.Run() if err != nil { sentry.CaptureException(err) } }
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  • Good rule of thumb to add some middleware with a token required 
// middleware.go package server import ( "net/http" "github.com/gin-gonic/gin" ) func AuthMiddleware() gin.HandlerFunc { authHeader := "let-me-in" // os.Getenv("AUTHORIZATION_STRING") return func(c *gin.Context) { requiredAuth := c.Request.Header.Get("Authorization") if requiredAuth != authHeader { c.AbortWithStatusJSON(http.StatusUnauthorized, map[string]string{"message": "unauthorized peasant 😃"}) } c.Next() // middleware } }
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  • Then we'll create default cors, routes and also call our middleware inside the router.use() method 
package server import ( "Intersect/scraper" "github.com/gin-contrib/cors" "github.com/gin-gonic/gin" ) /// router.go func NewRouter() *gin.Engine { // gin.SetMode(gin.ReleaseMode) router := gin.New() // Gin and CORS Middlewares router.Use(gin.Logger()) router.Use(gin.Recovery()) /// Cors router.Use(setCors()) /// Declare Middleware authorized := router.Group("/") authorized.Use(AuthMiddleware()) { authorized.GET("", scraper.Greet) searchRouter := authorized.Group("search") searchRouter.GET("", scraper.GetImgs) } return router } // Cors func setCors() gin.HandlerFunc { return cors.New(cors.Config{ AllowOrigins: []string{"*"}, AllowMethods: []string{"GET", "OPTIONS", "PUT"}, AllowHeaders: []string{"Origin", "Authorization"}, ExposeHeaders: []string{"Content-Length"}, AllowCredentials: true, }) }
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Then we'll create a scraper directory/module and create two files

  • greeting.go for default route and
  • search.go for the request route. (Because the default route will be lonely). 
package scraper import ( "net/http" "github.com/gin-gonic/gin" ) func Greet(c *gin.Context) { c.JSON(http.StatusOK, map[string]string{"sup": "🤘🚀"}) }
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package scraper import ( "fmt" "net/http" "strings" "github.com/gin-gonic/gin" "github.com/gocolly/colly" ) func GetImgs(c *gin.Context) { searchQuery := c.Query("q") res := getSearch(searchQuery) c.JSON(http.StatusOK, res) } func getSearch(searchQuery string) Images { searchString := strings.Replace(searchQuery, " ", "-", -1) c := colly.NewCollector() c.UserAgent = "Mozilla/5.0 (Macintosh; Intel Mac OS X x.y; rv:42.0) Gecko/20100101 Firefox/42.0" c.AllowURLRevisit = true c.DisableCookies() array := []string{} // Find and visit all links c.OnHTML("img[src]", func(e *colly.HTMLElement) { src := e.Attr("src") if src != "" { array = append(array, e.Attr("src")) } }) // Requesting a url for html c.OnRequest(func(r *colly.Request) { fmt.Println("Visiting", r.URL) }) // search query pexelsQuery := strings.Replace(searchString, "-", "%20", -1) stocSnapQuery := strings.Replace(searchString, "-", "+", -1) // c.Visit("https://unsplash.com/s/" + searchString) c.Visit("https://burst.shopify.com/photos/search?utf8=%E2%9C%93&q=" + searchString + "&button=") c.Visit("https://www.pexels.com/search/" + pexelsQuery + "/") c.Visit("https://www.flickr.com/search/?text=" + pexelsQuery) c.Visit("http://www.google.com/images?q=" + stocSnapQuery) c.Visit("https://stocksnap.io/search/" + stocSnapQuery) // return Images{ Count: len(array), Data: array} } type Images struct { Count int `json:"counts"` Data []string `json:"data"` }
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After that, we'll build a binary using

go build -o /bin/Intersect_api -v .
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Now that's almost all the code we'll need.

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