Connect to a PostgreSQL cluster

Last update: May 28 2025

Connect to a PostgreSQL cluster

You can connect to a PostgreSQL cloud database cluster by DNS address, private IP address, and public IP address.

We recommend connecting by DNS address because DNS addresses correspond to node roles and lead to the actual IP addresses of the master and replicas. IP addresses correspond to specific nodes. If the master is unavailable, one of the replicas will assume its role, the master's IP address will change, and the IP connection will stop working.

If the cluster is connected to a private subnet and you want to work with it via DNS, connect the cluster subnet to a cloud router with access to the external network. Use the instructions Set up Internet access through the cloud router.

If the cluster is connected to a private network and you need to configure access to the node from the Internet, connect a public IP address.

Ports⁠

Use ports to connect to PostgreSQL:

• 5433 — port for connecting to the selected node via connection pooler — allows to reduce the load on PostgreSQL;
• 5432 is the port to connect directly to the PostgreSQL process.

Ways of connection⁠

• through the psql terminal client;
• through graphical database management tools: pgAdmin or an office suite with ODBC or JDBC support;
• from program code with and without SSL.

Connection with SSL certificate is available for all methods.

View the address for connection⁠

1. In the Control panel, on the top menu, click Products and select Cloud Databases.
2. Open the Active tab.
3. Open the Database Cluster page → Connection tab.
4. In the Addresses to connect block, look up the address.

Connect with SSL⁠

Connecting using TLS/SSL encryption provides a secure connection between your server and the database cluster.

Bash

1. Download the root certificate and place it in the ~/.postgresql/ folder:

   mkdir -p ~/.postgresql/
   wget https://storage.dbaas.selcloud.ru/CA.pem -O ~/.postgresql/root.crt
   chmod 0600 ~/.postgresql/root.crt

2. Connect to the cluster:

   psql "host=<host>
   port=<port>
   dbname=<database_name>
   user=<database_user_name> 
   sslmode=verify-ca"

   Specify:

   • <host> — DNS address of the node;
   • <port> — port to connect to;
   • <database_name> — database name;
   • <database_user_name> — database user name.

PowerShell

1. In the control panel, click Download Certificate to download the root certificate and place it in the %APPDATA% \postgresql\ folder.

2. Connect to the cluster:

   psql --host=<host> \
       --port=<port> \
       --user=<database_user_name> \
       --dbname=<database_name> \
       --sslmode=verify-ca

   Specify:

   • <host> — DNS address of the node;
   • <port> — port to connect to;
   • <database_user_name> — database user name;
   • <database_name> — database name.

Python

1. Download the root certificate and place it in the ~/.postgresql/ folder:

   mkdir -p ~/.postgresql/
   wget https://storage.dbaas.selcloud.ru/CA.pem -O ~/.postgresql/root.crt
   chmod 0600 ~/.postgresql/root.crt

2. Install the psycopg2 library:

   pip3 install psycopg2-binary

3. Use the connection example:

   import psycopg2
   
   conn = psycopg2.connect("""
         host=<host>
         dbname=<database_name>
         user=<database_user_name>
         password=<password>
         sslrootcert=<path>
         sslmode=verify-ca
         port=<port>
   """)
   
   cur = conn.cursor()
   cur.execute('SELECT 40+2')
   
   print(cur.fetchone())
   
   cur.close()
   conn.close()

   Specify:

   • <host> — DNS address of the node;
   • <database_name> — database name;
   • <database_user_name> — database user name;
   • <password> — user password;
   • <path> — the full path to the root certificate;
   • <port> — port to connect to.

PHP

1. Download the root certificate and place it in the ~/.postgresql/ folder:

   mkdir -p ~/.postgresql/
   wget https://storage.dbaas.selcloud.ru/CA.pem -O ~/.postgresql/root.crt
   chmod 0600 ~/.postgresql/root.crt

2. Install the pgsql library:

   apt install php-pgsql

3. Use the connection example:

   <?php
   
   $dbconn = pg_connect("
         host=<host>
         dbname=<database_name>
         user=<database_user_name>
         password=<password>
         sslrootcert=<path>
         sslmode=verify-ca
         port=<port>
   ");
   
   $query = 'SELECT 40 + 2';
   $result = pg_query($query);
   $row = pg_fetch_row($result);
   
   echo $row[0];
   
   pg_close($dbconn);
   ?>

   Specify:

   • <host> — DNS address of the node;
   • <database_name> — database name;
   • <database_user_name> — database user name;
   • <password> — user password;
   • <path> — the full path to the root certificate;
   • <port> — port to connect to.

Go

1. Download the root certificate and place it in the ~/.postgresql/ folder:

   mkdir -p ~/.postgresql/
   wget https://storage.dbaas.selcloud.ru/CA.pem -O ~/.postgresql/root.crt
   chmod 0600 ~/.postgresql/root.crt

2. Use the connection example:

   package main
   
   import (
         "context"
         "fmt"
         "os"
   
         "github.com/jackc/pgx/v4"
   )
   
   func main() {
   
         connectionString := fmt.Sprintf("postgres://%s:%s@%s:5432/%s?sslmode=verify-ca&sslrootcert=%s",
             "<database_user_name>",
             "<password>",
             "<host>",
             "<database_name>",
             "<path>"
         )
   
         conn, err := pgx.Connect(context.Background(), connectionString)
         if err != nil {
             fmt.Fprintf(os.Stderr, "Unable to connect to database: %v\n", err)
             os.Exit(1)
         }
         defer conn.Close(context.Background())
   
         var sum int64
         err = conn.QueryRow(context.Background(), "SELECT 40+2").Scan(&sum)
         if err != nil {
             fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
             os.Exit(1)
         }
   
         fmt.Println(sum)
   }

   Specify:

   • <database_user_name> — database user name;
   • <password> — user password;
   • <host> — DNS address of the node;
   • <database_name> — database name;
   • <path> — the full path to the root certificate.

Node.js

1. Download the root certificate and place it in the ~/.postgresql/ folder:

   mkdir -p ~/.postgresql/
   wget https://storage.dbaas.selcloud.ru/CA.pem -O ~/.postgresql/root.crt
   chmod 0600 ~/.postgresql/root.crt

2. Install the pg library:

   npm install pg

3. Use the connection example:

   const fs = require('fs');
   const pg = require('pg');
   
   const config = {
       host: '<host>',
       port: '<port>',
       database: '<database_name>',
       user: '<database_user_name>',
       password: '<password>',
       ssl: {
         rejectUnauthorized: true,
         ca: fs.readFileSync('<path>').toString(),
       },
   };
   
   const client = new pg.Client(config);
   
   client.connect((error) => {
       if (error) throw error;
   });
   
   client.query('SELECT 40 + 2 AS sum', (error, res) => {
       if (error) throw error;
       console.log(res.rows);
       client.end();
   });

   Specify:

   • <host> — DNS address of the node;
   • <port> — port to connect to;
   • <database_name> — database name;
   • <database_user_name> — database user name;
   • <password> — user password;
   • <path> — the full path to the root certificate.

Connect without SSL⁠

Bash

1. Open the CLI.

2. Connect to the cluster:

   psql "host=<host>
   port=<port>
   dbname=<database_name>
   user=<database_user_name> 
     --sslmode=disable"

   Specify:

   • <host> — DNS address of the node;
   • <port> — port to connect to;
   • <database_name> — database name;
   • <database_user_name> — database user name.

PowerShell

1. Open the CLI.

2. Connect to the cluster:

   psql --host=<host> \
     --port=<port> \
     --user=<database_user_name> \
     --dbname=<database_name> \
     --sslmode=disable

   Specify:

   • <host> — DNS address of the node;
   • <port> — port to connect to;
   • <database_user_name> — database user name;
   • <database_name> — database name.

Python

1. Install the psycopg2 library:

   pip3 install psycopg2-binary

2. Use the connection example:

   import psycopg2
   
   conn = psycopg2.connect("""
         host=<host>
         dbname=<database_name>
         user=<database_user_name>
         password=<password>
         port=<port>
   """)
   
   cur = conn.cursor()
   cur.execute('SELECT 40+2')
   
   print(cur.fetchone())
   
   cur.close()
   conn.close()

   Specify:

   • <host> — DNS address of the node;
   • <database_name> — database name;
   • <database_user_name> — database user name;
   • <password> — user password;
   • <port> — port to connect to.

PHP

1. Install the pgsql library:

   apt install php-pgsql

2. Use the connection example:

   <?php
   
   $dbconn = pg_connect("
         host=<host>
         dbname=<database_name>
         user=<database_user_name>
         password=<password>
         port=<port>
   ");
   
   $query = 'SELECT 40 + 2';
   $result = pg_query($query);
   $row = pg_fetch_row($result);
   
   echo $row[0];
   
   pg_close($dbconn);
   ?>

   Specify:

   • <host> — DNS address of the node;
   • <database_name> — database name;
   • <database_user_name> — database user name;
   • <password> — user password;
   • <port> — port to connect to.

Go

Use the connection example:

package main

import (
    "context"
    "fmt"
    "os"

    "github.com/jackc/pgx/v4"
)

func main() {
    connectionString := fmt.Sprintf("postgres://%s:%s@%s:5432/%s",
        "<database_user_name>",
        "<password>",
        "<host>",
        "<database_name>",
    )

    conn, err := pgx.Connect(context.Background(), connectionString)
    if err != nil {
        fmt.Fprintf(os.Stderr, "Unable to connect to database: %v\n", err)
        os.Exit(1)
    }
    defer conn.Close(context.Background())

    var sum int64
    err = conn.QueryRow(context.Background(), "SELECT 40+2").Scan(&sum)
    if err != nil {
        fmt.Fprintf(os.Stderr, "QueryRow failed: %v\n", err)
        os.Exit(1)
    }

    fmt.Println(sum)
}

Specify:

• <database_user_name> — database user name;
• <password> — user password;
• <host> — DNS address of the node;
• <database_name> — database name.

Node.js

1. Install the pg library:

   npm install pg

2. Use the connection example:

   const pg = require('pg');
   
   const config = {
       host: '<host>',
       port: '<port>',
       database: '<database_name>',
       user: '<database_user_name>',
       password: '<password>',
   };
   
   const client = new pg.Client(config);
   
   client.connect((error) => {
       if (error) throw error;
   });
   
   client.query('SELECT 40 + 2 AS sum', (error, res) => {
       if (error) throw error;
       console.log(res.rows);
       client.end();
   });

   Specify:

   • <host> — DNS address of the node;
   • <port> — port to connect to;
   • <database_name> — database name;
   • <database_user_name> — database user name;
   • <password> — user password.