Installation Preconditions

Before installing CloudBlue Commerce, make sure that the following preconditions are met:

The physical server designated to be the CloudBlue Commerce MN meets these requirements.

Important: If CloudBlue Commerce MN is running RHEL 7, it should be subscribed to 'optional' channel. Please refer to RHEL documentation for the details.
PostgreSQL meets the following requirements:
- PostgreSQL is installed on a separate virtual machine or as a cluster.
- A password is set for the PostgreSQL admin user.
- The admin user is allowed to connect remotely to the PostgreSQL server from Operations MN.
At least one external DNS server is configured.
SMTP server with the open relay for MN is configured. This SMTP server should be connected to both the BackNet and FrontNet networks. MN will use the SMTP server to send a mail notification to the Internet.
YUM package-management utility is installed on the server; the YUM OS repositories are configured and accessible from the server (to validate this, use the yum install <PACKAGE_NAME> command).

Important: To keep your Linux infrastructure secure, it’s necessary to keep the installed OSes up-to-date. The OS updates are provided by YUM repositories, so it is necessary to configure repositories on each Linux-based hardware node. For large Linux infrastructures, we recommend that you configure local yum mirrors or Red Hat Network (RHN) proxies to reduce bandwidth consumption and provide the ability to limit Internet access from hosts. You can get additional information on how to configure local mirrors from the following resources:

- Red Hat Network (RHN) Frequently Asked Questions: https://access.redhat.com/knowledge/node/15979;
- Creating Local Mirrors for Updates or Installs: http://wiki.centos.org/HowTos/CreateLocalMirror.

For instructions on how to update Linux-based hardware nodes registered in CloudBlue Commerce, refer to Operations Provider's Guide >> Managing Hardware Nodes > Updating Linux-based Hardware Nodes section.
Update system software on the host using the yum update command.
Hostname of MN is resolved through resolver DNS servers into the BackNet IP address of MN.

If you are installing CloudBlue Commerce on physical server, the following supplementary preconditions must be met:

The target server is assigned a BackNet IP address (it is assigned during configuring the server for MN installation).
Hostname for the server is configured in the /etc/hosts file along with the BackNet IP address.
Resolver DNS servers are specified in the /etc/resolv.conf file in the format:
```
nameserver RESOLVER_DNS_SERVER_IP_ADDRESS
```
RESOLVER_DNS_SERVER_IP_ADDRESS - is an IP address of resolver DNS server. If you have several DNS servers, specify all of them in that file. It will look like:
```
nameserver RESOLVER_DNS_SERVER_IP_ADDRESS

nameserver RESOLVER_DNS_SERVER_IP_ADDRESS

nameserver RESOLVER_DNS_SERVER_IP_ADDRESS
```

Important: The MN hostname must explicitly contain the 'dot' symbol. For example, host.com.