ants-client 3.0.5

ANTS Framework client

ANTS is a framework to manage and apply macOS and Linux host configurations using Ansible Pull.

The ANTS Framework is developed by the Client Services Team of the University of Basel IT Services and released under the GNU General Public License Version 3.

Ansible is a trademark of Red Hat, Inc.

Introduction

The ANTS Framework consists of the following components:

• A wrapper for Ansible-Pull

• An Ansible Dynamic Inventory Script (MS Active Directory Connector)

• A modular collection of roles ready to be used

• Strong logging integration

Requirements

This project assumes that you are familiar with Ansible , Git and the shell.

Getting started

Installing ants using pip

• Make sure git is installed on your machine

• Install the latest ants client using pip: pip install ants_client

• Pip will install the ANTS client with a default configuration and put the executable in your path.

Installing ants using macOS .pkg installer

• Download the latest .pkg installer from the releases page.

• Execute the installer. This will take care of all dependencies.

• A launch daemon will be installed, running ants every 15 minutes. It will trigger after the next restart.

Run ants

• Open your terminal

• Start an ANTS run by typing ants.

• Wait for ANTS to finish, then open another shell. You will see a new message of the day.

What happened?

Running ANTS with the default configuration will use ansible-pull to clone the ANTS playbook via https from a github repository and execute an ansible run.

By default, this will generate /etc/motd to add a message of the day to your macOS or Linux host. Logs of all the runs are stored at /var/log/ants.

Also by default, ants will add github to your known_hosts file. This is important for later, when you want to enable git clone using ssh.

Where to go from here?

Look at the options

Run ants -h to see all command line options.

Write your own configuration

Run ants --show-config to see the active configuration.

Run ants --initialize to write your own configuration.

Your local configuration file will be saved at /etc/ants/ants.cfg. You can also edit it using your favorite text editor.

Do not modify the default configuration file as it might be overwritten when updating ANTS.

On Mac OS, you can also configure ANTS with a preference list (plist) or configuration profile. Please note that configurations set in this manner will override any other configuration, including ants.cfg. Go here for an example configuration profile.

Run other roles

Fork or duplicate our example playbook and change the client configuration to point to your repository. Update main.yml to assign different roles to your hosts.

You can use the default Ansible syntax. You can also use wildcards. Have a look at the Ansible documentation

Add ssh authentication to your repository

Ansible-pull can clone a git repository using ssh. You can enable this by creating your own private playbook, adding ssh authentication and a read only ssh key to the repository. Configure ANTS to use that key.

By default, ANTS will look for a private key at /etc/ants/id_ants

You can generate a key with ssh-keygen -t rsa -b 4096 -N '' -C "ants client" -f /etc/ants/id_ants

By default, ANTS is configured to run with strict host key checking disabled and will add the host key for your repo to your known_hosts file. You should change this in production. To do so, add ssh_stricthostkeychecking = True to your ants.cfg

Add a dynamic inventory source

Ansible supports dynamic inventory scripts. (A json representation of hosts to group mappings.)

You can use scripts to tell ansible-pull which tasks to run on which host. You need an inventory source and a script that can read and return it in the correct format.

By default, ANTS will run a dummy script inventory_default that will just return your hostname belonging to a group named ants-common. You can edit main.yml straight away and assign roles using host names. But ANTS shows it’s real power when ansible-pull is combined with a dynamic inventory using group mappings.

For this we provide the inventory_ad script which will connect to your Active Directory and return all groups your host is a member of. Just add your configuration to /etc/ants/ants.cfg. Note that read only rights for the Active Directory user are sufficient.

Your host DOSN’T have to be bound to Active Directory in order for this to work. You can use a placeholder object.

By using a dynamic inventory source, you can assign roles to a host using AD and let ANTS handle the configuration.

Group Layout in Active Directory

The groups in Active Directory must have the same names as the mappings and the variables you want to assign using Ansible. We recommend to keep the groups in a dedicated Organizational Unit to prevent naming collisions.

Nested groups with access restrictions are an easy way to offer rights delegation to other units in your organization.

What else do I need

Nothing. You just set up a configuration management that communicates savely over ssh using your AD and Github.

No additional infrastructure and no AD binding required.

Add your own inventory file

You can add your own inventory file. This can be a dynamic inventory source or a static file. By default, ANTS will look for the inventory file in its python package. This is useful because it enables you to use inventory scripts like inventory_ad without having to specify the full path. However, if you would like to place your inventory file somewhere else you’re free to do so. All you have to do is use an absolute path in ants.cfg.

The following entry in ants.cfg will look for your inventory file in the ANTS python package. This is useful for everything that comes with the ANTS installation:

[main]
inventory_script = inventory_ad

This entry on the other hand will look for your inventory file in /etc/ants:

[main]
inventory_script = /etc/ants/myinventory

Callback plugins and reporting

ANTS can be configured to execute ansible callback plugins. We will cover the most common use case here: log ANTS information to logstash.

ANTS ships with a modified version of the default ansible logstash plugin. If you want to use plugins that are installed at a custom location you can specify your path in the ants.cfg config file under ansible_callback_plugins.

In order for ANTS to execute the callback plugin, just add the following entries to the config file: ansible_callback_whitelist = ants_logstash and add a new section called [callback_plugins]. This section should contain the LOGSTASH_SERVER and the LOGSTASH_PORT. ANTS will set the environment variables according to these values. Environment variables will only be added if the ansible_callback_whitelist is not empty.

You can add other callback plugins to ansible_callback_whitelist if you desire. The same is true for [callback_plugins]. Just add environment variables to that sub section.

Please note that the casing of the environment variables is essential for the callback plugins to work. The casing can be found using ansible-doc -t callback logstash $name_of_plugin.

Testing and Development

You made changes to the ANTS code or you want to test a feature that hasn’t been released yet? This is what you should do:

If what you’re looking for is already available in pypi as a pre-release, you can simply install it by telling pip to include pre-releases in its search: pip install ants_client --pre

If you made local changes to your code and want to test them, you can set up a virtual environment, activate it and install your code locally using pip install -e <path_to_ants>.

Make sure all inventory files are found. You can run a local dev version of ants ANTS using the following commands:

git clone https://github.com/ANTS-Framework/ants.git ants_dev
cd ants_dev
python3 -m venv venv
source venv/bin/activate
python -m pip install -e .
sudo ants --ansible_pull_exe $(which ansible-pull) -i $(which inventory_ad) -vvv

Communication

• Please use the GitHub issue tracker to file issues.

• Please use a GitHub Pull-Request to suggest changes.

Comparison of plain Ansible and Ansible Tower to ANTS

What does ANTS do, that Ansible can not?

• ANTS gives you a set of ready to be used roles for typical macOS and Linux host configurations.

• ANTS let’s you utilize Active Directory to map computers to roles. With all it’s delegation and nesting features.

• ANTS utilizes Ansible Pull and therefore does not require an active network connection to a central server. Roles will be locally applied even if the host is offline.

What does Ansible or Ansible Tower do that ANTS does not?

• Tower has a nice Dashboard

• Tower has a real time job output and push-button job runs

• Tower can to job scheduling

• Tower supports run-time job promoting

• Tower supports workflows

• Ansbile can use encrypted secrets using Vault

• Ansible and Tower do offer Enterprise Support