Configure CentOS

You must configure the base operating system of your node machines to use Distributed Cloud. This page contains the steps you need to take to complete the needed configuration.
For more information about troubleshooting Distributed Cloud requirements, see the troubleshooting guides .

Before you begin

Ensure you are using a supported version of your operating system. Anthos on bare metal supports the following versions for CentOS:

• CentOS 8.2
• CentOS 8.3
• CentOS 8.4
• CentOS 8.5

Ensure you have root access to the machines you are configuring. Validate Package manager with the following steps:

1. Check for updates:

    sudo  
   dnf  
   check-update 
   

2. Ensure the output has no errors and includes the last metadata expiration check. For example:

    # Last metadata expiration check: ...
   ...
   google-cloud-sdk.x86_64 ... 
   

Configure or disable firewalld

Firewalld can be configured for use with Google Distributed Cloud or disabled. For information on configuring firewalld, see Configuring firewalld ports on the Network requirements page.

The following instructions disable firewalld.

1. Disable firewalld:

    sudo  
   systemctl  
   stop  
   firewalld 
    sudo  
   systemctl  
   disable  
   firewalld 
   

2. Check the status of firewalld to ensure it is disabled:

    sudo  
   systemctl  
   status  
   firewalld  
    | 
     
   grep  
    "Active" 
    # Output 
    # Active: inactive (dead) 
    
   

Configure Docker 19.03+ on your workstation

Follow these steps to manually install Docker:

1. Remove any previous Docker version:

    sudo  
   dnf  
   remove  
   docker  
    \ 
     
   docker-client  
    \ 
     
   docker-client-latest  
    \ 
     
   docker-common  
    \ 
     
   docker-latest  
    \ 
     
   docker-latest-logrotate  
    \ 
     
   docker-logrotate  
    \ 
     
   docker-engine 
   

2. Remove podman-manpages

    sudo dnf remove podman-manpages 
   

3. Install Docker 19.03+:

    sudo  
   dnf  
   install  
   -y  
   yum-utils 
    sudo  
   yum-config-manager  
    \ 
     
   --add-repo  
    \ 
     
   https://download.docker.com/linux/centos/docker-ce.repo 
    sudo  
   dnf  
   install  
   -y  
   docker-ce  
   docker-ce-cli  
   containerd.io 
    sudo  
   systemctl  
   start  
   docker 
   

4. Verify you are now running version 19.03+:

    sudo  
   docker  
   version 
   

5. Compare your output with the following example to ensure the Client and Server versions are 19.03+ :

    Client: Docker Engine - Community
    Version:           19.03.13
    ...
    Server: Docker Engine - Community
     Engine:
     Version:          19.03.13 
   

Set up time synchronization

Time synchronization consists of setting the clocks on your node machines, using a designated external time reference. Time synchronization is important for time-sentive cluster activities, such as event logging and metrics collection. The kernel of your node machine controls the clock in containers that run on the node. To ensure proper time synchronization, install a network time protocol (NTP) service on your machines, using any of the available services: chrony , systemd- timesyncd , ntp , or ntpdate . Run timedatectl to verify that the system clock is synchronized. The output of timedatectl should contain the following status:

 System clock synchronized: yes