Introduction

The deployment of ESGF Nodes has traditionally been done by a mix of scripts and manual admin actions. This repository holds files which are used by the popular automated system configuration tool Ansible that will perform the ESGF Node deployment.

Ansible runs from a control machine and deploys the configuration to managed machines via SSH.

For all the details and features of Ansible see the Ansible Docs.

Requirements

Here is a summary of the requirements, see Ansible Installation for more information.

	Control Machine	Managed Machine
OS	Any, Not Windows	CentOS 6/7
Python	>=2.7	2 (CentOS 6/7 has 2.6/7)
Ansible	2.7	None
Other	SSH to Managed Machine	Account with escalated privileges

Additional Info

The simple requirements for the control machine is to have Ansible installed in some way. This can be done via a system package manager, or simply via pip, the Python package manager into a Python environment. The later is the recommended way as this repository was developed and tested with the latest Ansible at the time, 2.7. It has been found that Ansible 2.4 is not supported. Using anything other than Ansible 2.7 will result in untested behavior.

The requirements for the managed machine are that it can be accessed via SSH from the control machine and that the managed machine has a Python interpreter. Also, an ESGF requirement is that the OS of the managed machine must be CentOS 6 or 7. Work is being done to support RedHat 6 and 7 as well. Ansible works reliably with Python 2 on the managed machine. Ansible is working towards supporting Python 3 on managed machines, see Ansible’s remarks, but is aware of incompatabilities. Since the system Python on CentOS/Redhat 6 and 7 is 2.6 and 2.7, respectively, this is not an issue. Also, there must be some way to have escalated privileges on the managed machine to deploy the configuration. This is described more below.