MartinHeinz/blog-backend

package main

import (
    "fmt"
    "github.com/MartinHeinz/blog-backend/cmd/blog_backend/apis"
    "github.com/MartinHeinz/blog-backend/cmd/blog_backend/config"
    "github.com/MartinHeinz/blog-backend/cmd/blog_backend/middleware"
    brotli "github.com/anargu/gin-brotli"
    "github.com/gin-gonic/gin"
    "github.com/prometheus/client_golang/prometheus"
    "github.com/prometheus/client_golang/prometheus/promhttp"
    "gorm.io/driver/postgres"
    "gorm.io/gorm"
    dbprom "gorm.io/plugin/prometheus"
    "log"
)

func prometheusHandler() gin.HandlerFunc {
    h := promhttp.HandlerFor(
        prometheus.DefaultGatherer,
        promhttp.HandlerOpts{
            // Opt into OpenMetrics to support exemplars.
            EnableOpenMetrics: true,
        },
    )

    return func(c *gin.Context) {
        h.ServeHTTP(c.Writer, c.Request)
    }
}

func main() {
    // load application configurations
    if err := config.LoadConfig("./config"); err != nil {
        panic(fmt.Errorf("invalid application configuration: %s", err))
    }

    // Creates a router without any middleware by default
    r := gin.New()
    http := gin.Default()

    // Global middleware
    // Logger middleware will write the logs to gin.DefaultWriter even if you set with GIN_MODE=release.
    // By default gin.DefaultWriter = os.Stdout
    r.Use(gin.Logger())

    // Recovery middleware recovers from any panics and writes a 500 if there was one.
    r.Use(gin.Recovery())

    r.Use(middleware.CORSMiddleware())
    r.Use(brotli.Brotli(brotli.DefaultCompression))

    v1 := r.Group("/api/v1")
    {
        v1.GET("/posts/by-id/:id", apis.GetPost)
        v1.GET("/posts/by-tag/:tag_name", apis.GetPostsByTag)
        v1.GET("/posts/", apis.GetPosts)
        v1.GET("/tags/:post_id", apis.GetTags)
        v1.GET("/sections/:post_id", apis.GetSections)
        v1.GET("/books/", apis.GetBooks)
        v1.GET("/projects/", apis.GetProjects)
        v1.POST("/newsletter/subscribe/", apis.AddSubscriber)
    }

    http.GET("/metrics/", prometheusHandler())

    config.Config.DB, config.Config.DBErr = gorm.Open(postgres.Open(config.Config.DSN))
    if config.Config.DBErr != nil {
        panic(config.Config.DBErr)
    }

    config.Config.DB.Use(dbprom.New(dbprom.Config{
        DBName:          "blog",
        RefreshInterval: 15,
        StartServer:     false,
        MetricsCollector: []dbprom.MetricsCollector{
            &dbprom.Postgres{},
        },
    }))

    // config.Config.DB.Migrator().AutoMigrate(&models.Post{}, &models.Project{}, &models.Section{}, &models.Tag{}, &models.Book{}) // This is needed for generation of schema for postgres image.

    sqlDB, err := config.Config.DB.DB()
    if err != nil {
        log.Fatalln(err)
    }
    defer sqlDB.Close()

    fmt.Println(fmt.Sprintf("Successfully connected to :%v", config.Config.DSN))

    go r.RunTLS(fmt.Sprintf(":%v", config.Config.ServerPort), config.Config.CertFile, config.Config.KeyFile)
    http.Run(":9080")
}