how do I connect gorm postgres to grpc golang

Question

I tried to connect gorm postgres to my code (golang language), but when I run it it gives this error:

2023/11/14 07:10:15 C:/Users/Professional/Desktop/проектики
голанга/filmgrpc/service/DB.go:40 [error] failed to initialize
database, got error failed to connect to `host=localhost user=user
database=db`: dial error (dial tcp 127.0.0.1:5432: connectex: No
connection could be made because the target machine actively refused
it.)

2023/11/14 07:10:15 C:/Users/Professional/Desktop/проектики
голанга/filmgrpc/service/DB.go:41 failed to connect to `host=localhost
user=user database=db`: dial error (dial tcp 127.0.0.1:5432:
connectex: No connection could be made because the target machine
actively refused it.) [0.515ms] [rows:-] SELECT count(*) FROM
information_schema.tables WHERE table_schema = CURRENT_SCHEMA() AND
table_name = 'films' AND table_type = 'BASE TABLE'

2023/11/14 07:10:15 C:/Users/Professional/Desktop/проектики
голанга/filmgrpc/service/DB.go:41 failed to connect to `host=localhost
user=user database=db`: dial error (dial tcp 127.0.0.1:5432:
connectex: No connection could be made because the target machine
actively refused it.) [0.518ms] [rows:0] CREATE TABLE "films" ("id"
text,"title" text,"genre" text,"created_at" timestamptz,"updated_at"
timestamptz,PRIMARY KEY ("id")) 2023/11/14 07:10:15 Error connecting
to the database...failed to connect to `host=localhost user=user
database=db`: dial error (dial tcp 127.0.0.1:5432: connectex: No
connection could be made because the target machine actively refused
it.) exit status 1

package main

import (
    "fmt"
    "log"
    "time"

    "gorm.io/driver/postgres"
    "gorm.io/gorm"
)

func init() {
    DatabaseConnection()
}

var DB *gorm.DB
var err error

type Film struct {
    ID        string `gorm:"primarykey"`
    Title     string
    Genre     string
    CreatedAt time.Time `gorm:"autoCreateTime:false"`
    UpdatedAt time.Time `gorm:"autoUpdateTime:false"`
}

func DatabaseConnection() {
    host := "localhost"
    port := "5432"
    dbname := "db"
    dbuser := "user"
    password := "pass"
    dsn := fmt.Sprintf("host=%s port=%s user=%s dbname=%s password=%s sslmode=disable",
        host,
        port,
        dbuser,
        dbname,
        password,
    )
    DB, err = gorm.Open(postgres.Open(dsn), &gorm.Config{})
    DB.AutoMigrate(Film{})
    if err != nil {
        log.Fatal("Error connecting to the database...", err)
    }
    fmt.Println("Database connection successful...")
}

I also thought that I should try it with Docker (here is the command docker run -it --name film-frnxx -e POSTGRES_PASSWORD=password -e POSTGRES_USER=dbuser -e POSTGRES_DB=dbname -e POSTGRES_PORT=port postgres).

The code itself seems to be correct.

Answer 1

It suggests that there is no PostgreSQL server running on the specified host and port, or the server is actively refusing the connection.

1-Check PostgreSQL Server: Ensure that PostgreSQL is installed on your machine, and the server is running. You can use the following command to start the PostgreSQL server:

service postgresql start

Make sure to replace service with the appropriate command for your operating system.

2-Check Firewall Settings

3-Check PostgreSQL Authentication: Ensure that the PostgreSQL server is configured to allow connections from the specified user (dbuser) and that the password is correct. You might need to check the pg_hba.conf file for authentication settings.

4-Use gorm.Open at Runtime: Consider moving the gorm.Open call from the init function to the main function to ensure the connection attempt occurs when your application is running.