OS with Containers Ready application

Last update: October 16 2026Open in Markdown

You can install an OS with the pre-installed Containers Ready application on a dedicated server.

The Containers Ready application includes:

• Docker version 28.0.3 — a containerization platform for developing and running applications;
• plugins for running Docker Compose version 2.33.0;
• Portainer version 2.27.0 — a graphical interface for monitoring and managing Docker containers, images, and Docker networks.

Before installing the OS with the application, review the software license agreements included in the image.

Install an OS with Containers Ready

For Containers Ready to work, the dedicated server must be accessible from the internet.

To set up Containers Ready and configure Portainer when creating a server, you can specify user data — custom operating system configuration parameters.

You can open the Portainer panel using an IP address or a domain. To open the Portainer panel by domain, specify the domain in user data — after installing the OS, a TLS (SSL) certificate from Let’s Encrypt® will be automatically issued for the domain.

Specify a domain

1. In the control panel, in the top menu, click Products and select Dedicated Servers.

2. In the Servers section, open the server page → the Operating system tab.

3. Click Reinstall OS.

4. Optional: to securely connect to the server using the encrypted SSH protocol, select a previously uploaded and placed SSH key or add a new one. For details, see the Create and upload an SSH key to a dedicated server instructions.

5. Enter user data. You can use user data to automate server configuration. You can only specify user data for servers without hardware HBA and RAID controllers.

   You can use a script in user data to configure container setups. To open the Portainer panel via a domain, insert the following script into the user data field:

   #cloud-config
   
   write_files:
     - path: "/opt/containers/docker-compose.yaml"
       permissions: "0644"
       content: |
         version: "3.9"
         services:
           <containers>
   
     - path: "/opt/containers/.env"
       permissions: "0644"
       content: |
         <environment-variables>
   
     - path: "/opt/user-values.yaml"
       permissions: "0644"
       content: |
         portainer_use_le: true
         portainer_domain: "<example.com>"
         portainer_le_email: "<root@example.com>"

   Specify:

   • <containers> — Docker Compose file contents for the docker-compose.yaml file. For details, see the docker compose instructions in the Docker documentation;
   • <environment-variables> — environment variables for the .env file. If the file is not needed, delete the code block. For details, see the Use environment variables instructions in the Docker documentation;
   • in the content: code block for the /opt/user-values.yaml file, specify the configuration parameters for Portainer;
   • portainer_use_le: true — parameter for automatically issuing a TLS (SSL) certificate from Let’s Encrypt®;
   • <example.com> — domain to access Portainer. To open the domain using the server's public IP address, add an A record in your DNS hosting control panel and specify the server's public IP address as the record value. You can copy the IP address in the control panel: in the top menu, click Products → Dedicated Servers → server page → Operating system tab → in the IP field, click . If the domain is delegated to Selectel DNS hosting (actual), follow the Add resource record instructions. After the OS installation, a TLS (SSL) certificate from Let’s Encrypt® will be automatically issued for the domain. If a TLS (SSL) certificate issuance fails, the Portainer panel will be accessible via the server IP address;
   • <root@example.com> — Containers Ready administrator email address for creating an account and receiving Let’s Encrypt® notifications.
   Example script for User data

   #cloud-config
   
   write_files:
     - path: "/opt/containers/docker-compose.yaml"
       permissions: "0644"
       content: |
         version: "3.9"
         services:
           web:
               container_name: web
               image: "busybox"
               env_file: "/opt/containers/.env"
           db:
               container_name: db
               image: "busybox"
               env_file: "/opt/containers/.env"
   
     - path: "/opt/containers/.env"
       permissions: "0644"
       content: |
         APP_ENV=production
         LOG_LEVEL=info
         LOG_FORMAT=json
         LOG_OUTPUT=/var/log/app.log
   
     - path: "/opt/user-values.yaml"
       permissions: "0644"
       content: |
         portainer_use_le: true
         portainer_domain: "example.com"
         portainer_le_email: "root@example.com"

6. In the Distribution field, select Container Ready.

7. Optional: partition the disks. You can select the disk where the / root partition will be created and the OS installed. If four or more disks are installed on the server, you can configure them in pairs into different RAID levels, for example, RAID1 and RAID0.

   By default, the optimal RAID level is determined and only disks with partitions and disks in RAID are partitioned. If you leave the default partitioning, the OS will be installed on the first disk, according to the order of disk installation on the server — NVMe → SSD → HDD.

8. Click Install. The installation may take anywhere from 7 to 60 minutes depending on server performance and the selected distribution. If it takes longer, submit a ticket.

9. After installing the OS, a password will be generated to connect to the server, which is also used for logging in to the Portainer panel. You can copy the password in the control panel: in the top menu, click Products → Dedicated Servers → server page → Operating system tab → in the Password field, click . The password is visible for 24 hours from the start of OS installation or configuration change. If you forgot the server password, you can reset and recover it.

Not specifying a domain

1. In the control panel, in the top menu, click Products and select Dedicated Servers.

2. In the Servers section, open the server page → the Operating system tab.

3. Click Reinstall OS.

4. Optional: to securely connect to the server using the encrypted SSH protocol, select a previously uploaded and placed SSH key or add a new one. For details, see the Create and upload an SSH key to a dedicated server instructions.

5. Optional: enter user data. You can use user data to automate server configuration. You can only specify user data for servers without hardware HBA and RAID controllers.

   To set up container configurations, you need to insert the following script into the user data field:

   #cloud-config
   
   write_files:
     - path: "/opt/containers/docker-compose.yaml"
       permissions: "0644"
       content: |
         version: "3.9"
         services:
           <containers>
   
     - path: "/opt/containers/.env"
       permissions: "0644"
       content: |
         <environment-variables>

   Specify:

   • <containers> — Docker Compose file contents for the docker-compose.yaml file. For details, see the docker compose instructions in the Docker documentation;
   • <environment-variables> — environment variables for the .env file. If the file is not needed, delete the code block. For details, see the Use environment variables instructions in the Docker documentation.
   Example script for User data

   #cloud-config
   
   write_files:
     - path: "/opt/containers/docker-compose.yaml"
       permissions: "0644"
       content: |
         version: "3.9"
         services:
           web:
               container_name: web
               image: "busybox"
               env_file: "/opt/containers/.env"
           db:
               container_name: db
               image: "busybox"
               env_file: "/opt/containers/.env"
   
     - path: "/opt/containers/.env"
       permissions: "0644"
       content: |
         APP_ENV=production
         LOG_LEVEL=info
         LOG_FORMAT=json
         LOG_OUTPUT=/var/log/app.log

6. In the Distribution field, select Pre-installed Apps → Container Ready 28.0.0 (Ubuntu 24.04 LTS).

7. Optional: partition the disks. You can select the disk where the / root partition will be created and the OS installed. If four or more disks are installed on the server, you can configure them in pairs into different RAID levels, for example, RAID1 and RAID0.

   By default, the optimal RAID level is determined and only disks with partitions and disks in RAID are partitioned. If you leave the default partitioning, the OS will be installed on the first disk, according to the order of disk installation on the server — NVMe → SSD → HDD.

8. Click Install. The installation may take anywhere from 7 to 60 minutes depending on server performance and the selected distribution. If it takes longer, submit a ticket.

9. After installing the OS, a password will be generated to connect to the server, which is also used for logging in to the Portainer panel. You can copy the password in the control panel: in the top menu, click Products → Dedicated Servers → server page → Operating system tab → in the Password field, click . The password is visible for 24 hours from the start of OS installation or configuration change. If you forgot the server password, you can reset and recover it.

Connect to the Portainer panel

The address to connect to the Portainer panel depends on whether you specified a domain in the user data when installing the OS in step 5.

Domain is specified

1. Open the following page in your browser:

   https://<domain>:9443

   Specify <domain> — the domain name you entered when installing the OS in step 5 in the User data field.

2. Log in to the panel. Use:

   • username — admin;
   • password — your server password. You can copy it in the control panel: in the top menu, click Products → Dedicated Servers → server page → Operating system tab → in the Password field, click . The password is visible for 24 hours from the start of OS installation or configuration change. If you forgot the server password, you can reset and recover it.

Domain is not specified

1. Open the following page in your browser:

   http://<ip_address>:9000

   Specify <ip_address> — the server public IP address. You can copy it in the control panel: in the top menu, click Products → Dedicated Servers → server page → Operating system tab → in the IP field, click .

2. The browser will warn you about an insecure connection because there is no SSL certificate. Confirm that you want to proceed to the page.

3. Log in to the panel. Use:

   • username — admin;
   • password — your server password. You can copy it in the control panel: in the top menu, click Products → Dedicated Servers → server page → Operating system tab → in the Password field, click . The password is visible for 24 hours from the start of OS installation or configuration change. If you forgot the server password, you can reset and recover it.