Connect to a PostgreSQL cluster

Last update: June 04 2026

You can connect to a PostgreSQL cluster:

• via the psql console client;
• graphical tool for database management pgAdmin;
• office suites or applications with ODBC or JDBC support;
• program code.

For all methods, you can connect with SSL or without SSL.

When connecting, specify the port and address.

Connection ports

Use the following ports to connect to PostgreSQL:

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

Connection addresses

The connection address depends on the cluster subnet and where you are connecting from. You can choose an address based on one of the scenarios:

• connecting to a cluster in a public subnet;
• connecting from a private subnet to a cluster in a private subnet;
• connecting from the Internet to a cluster in a private subnet.

Connecting to a cluster in a public subnet

If a cluster is in a public subnet, you can connect to the nodes using a DNS address or an IP address from the public subnet.

We recommend connecting using a DNS address. DNS addresses use the master discovery mechanism in the cluster—the address is tied to the node role rather than the node itself. If a master becomes unavailable, one of the replicas becomes the new master, and the address moves to the new node along with the role.

The master discovery mechanism is not used when connecting via an IP address from a public subnet. If one of the replicas becomes the new master, the master's IP address will change, and the connection using the old IP address will stop working.

You can view the connection address in the Dashboard.

Connecting from a private subnet to a cluster in a private subnet

If you are connecting from a private subnet to a cluster in a private subnet, you can use a DNS address or a private IP address.

We recommend connecting using a DNS address. DNS addresses use the master discovery mechanism in the cluster—the address is tied to the node role rather than the node itself. If a master becomes unavailable, one of the replicas becomes the new master, and the address moves to the new node along with the role.

The master discovery mechanism is not used when connecting via a private IP address. If one of the replicas becomes the new master, the master's IP address will change, and the connection using the old IP address will stop working.

To connect from another private subnet, first connect both private subnets to a cloud router.

You can view the connection address in the Dashboard.

Connecting from the Internet to a cluster in a private subnet

If you are connecting to a cluster in a private subnet from the Internet, you can only use a public IP address (Floating IP). The private subnet must meet the requirements. If the subnet does not meet the requirements, prepare it for a public IP address (Floating IP).

Public IP addresses (Floating IPs) use the master discovery mechanism—the address is tied to the node role rather than the node itself. If a master becomes unavailable, one of the replicas becomes the new master, and the address moves to the new node along with the role.

You can view the connection address in the Dashboard.

View the connection address

1. In the Dashboard, in the top menu click Products and select Managed Databases.
2. Open the Active tab.
3. Open the database cluster page → Connection tab.
4. In the Connection addresses block, view the address.

Connect with SSL

Connecting with TLS(SSL) encryption ensures a secure connection between your server and the database cluster.

Bash

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

   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 or public IP address (Floating IP) of the node;
   • <port> — port for connection;
   • <database_name> — database name;
   • <database_user_name> — database username.

PowerShell

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

2. Connect to the cluster:

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

   Specify:

   • <host> — DNS address or public IP address (Floating IP) of the node;
   • <port> — port for connection;
   • <database_name> — database name;
   • <database_user_name> — database username.

Python

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

   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 or public IP address (Floating IP) of the node;
   • <database_name> — database name;
   • <database_user_name> — database username;
   • <password> — user password;
   • <path> — full path to the root certificate;
   • <port> — port for connection.

PHP

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

   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 or public IP address (Floating IP) of the node;
   • <database_name> — database name;
   • <database_user_name> — database username;
   • <password> — user password;
   • <path> — full path to the root certificate;
   • <port> — port for connection.

Go

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

   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:<port>/%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:

   • <port> — port for connection;
   • <database_user_name> — database username;
   • <password> — user password;
   • <host> — DNS address or public IP address (Floating IP) of the node;
   • <database_name> — database name;
   • <path> — full path to the root certificate.

Node.js

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

   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 or public IP address (Floating IP) of the node;
   • <port> — port for connection;
   • <database_name> — database name;
   • <database_user_name> — database username;
   • <password> — user password;
   • <path> — 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 or public IP address (Floating IP) of the node;
   • <port> — port for connection;
   • <database_name> — database name;
   • <database_user_name> — database username.

PowerShell

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 or public IP address (Floating IP) of the node;
   • <port> — port for connection;
   • <database_name> — database name;
   • <database_user_name> — database username.

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 or public IP address (Floating IP) of the node;
   • <database_name> — database name;
   • <database_user_name> — database username;
   • <password> — user password;
   • <port> — port for connection.

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 or public IP address (Floating IP) of the node;
   • <database_name> — database name;
   • <database_user_name> — database username;
   • <password> — user password;
   • <port> — port for connection.

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:<port>/%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:

• <port> — port for connection;
• <database_user_name> — database username;
• <password> — user password;
• <host> — DNS address or public IP address (Floating IP) 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 or public IP address (Floating IP) of the node;
   • <port> — port for connection;
   • <database_name> — database name;
   • <database_user_name> — database username;
   • <password> — user password.