EXTEND ANSIBLE: MODULES, PLUGINS and API

Should you want to write your own, Ansible modules can be written in any language that can return JSON (Ruby, Python, bash, etc). Inventory can also plug in to any datasource by writing a program that speaks to that datasource and returns JSON. There's also various Python APIs for extending Ansible’s connection types (SSH is not the only transport possible), callbacks (how Ansible logs, etc), and even for adding new server side behaviors

Files used by ansible

  ANSIBLE_CONFIG (environment variable if set) default: /etc/ansible/ansible.cfg
  ansible.cfg (in the current directory)
  ~/.ansible.cfg (in the home directory)
  /etc/ansible/ansible.cfg

You can generate an Ansible configuration file, ansible.cfg, that lists all default settings as follows:

ansible-config init --disabled > ansible.cfg

Include available plugins to create a more complete Ansible configuration as follows:

ansible-config init --disabled -t all > ansible.cfg

As specific user

$ pwd
/home/tux
$ ansible --version
ansible 2.9.15
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/tux/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3.6/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 3.6.8 (default, Apr 16 2020, 01:36:27)
  [GCC 8.3.1 20191121 (Red Hat 8.3.1-5)]

$ touch ~/.ansible.cfg
$ ansible --version | grep 'config file'
  config file = /home/tux/.ansible.cfg

First install ansible package

Configure /etc/ansible/hosts

it can contain hosts and group them

Ex:

  [webservers]
  www1.example.com ansible_ssh_user=root ansible_ssh_pass=mypassord
  www2.example.com

  [dbservers]
  db0.example.com
  db1.example.com
  10.1.1.1

Example of basic commands

# ansible all -m ping 
# ansible foo.example.com -m yum -a "name=httpd state=installed"
# ansible foo.example.com -a "/usr/sbin/reboot"
# ansible all -s -n shell -a 'cat /etc/redhat-release' 

Writing a playbook

Check syntax

ansible-playbook sample.yml --syntax-check

Add additionnal modules

[root@lnx100 ~]# ansible-galaxy collection install ibm.power_aix
Process install dependency map
Starting collection install process
Installing 'ibm.power_aix:1.2.1' to '/root/.ansible/collections/ansible_collections/ibm/power_aix'

Or specify another path for collections:

$ ansible-galaxy collection install ibm.power_aix -p /home/ansible/collections

There are 2 ways to

• into ansible.cfg into [defaults] section add the following parameter collections_paths
• Or use the environment variable ANSIBLE_COLLECTIONS_PATHS

To schedule jobs, you can use Ansible Tower, but also Rundeck which is free and contain a plugin for ansible

[root@lnx100 ~]# yum install ansible
Last metadata expiration check: 1:26:30 ago on Tue 31 Aug 2021 02:26:03 PM CEST.
Error:
 Problem: conflicting requests
  - nothing provides python-setuptools needed by ansible-2.9.24-2.el7.noarch
  - nothing provides python-six needed by ansible-2.9.24-2.el7.noarch
  - nothing provides PyYAML needed by ansible-2.9.24-2.el7.noarch
  - nothing provides python-jinja2 needed by ansible-2.9.24-2.el7.noarch
  - nothing provides python-paramiko needed by ansible-2.9.24-2.el7.noarch
  - nothing provides python-httplib2 needed by ansible-2.9.24-2.el7.noarch
  - nothing provides python2-cryptography needed by ansible-2.9.24-2.el7.noarch
  - nothing provides python2-jmespath needed by ansible-2.9.24-2.el7.noarch
(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)

Using PIP

[root@lnx100 ~]# pip3 install --proxy=http://myuser:mypass@myproxy:2123 ansible==2.9
WARNING: Running pip install with root privileges is generally not a good idea. Try `pip3 install --user` instead.
Collecting ansible
  Downloading https://files.pythonhosted.org/packages/b5/01/dd6bf3cb7d834c7493d10fa1f0720c34c7703fc9bf12c93f294def465bb0/ansible-4.4.0.tar.gz (35.4MB)
    100% |████████████████████████████████| 35.4MB 36kB/s
Collecting ansible-core<2.12,>=2.11.3 (from ansible)
  Downloading https://files.pythonhosted.org/packages/98/3c/1305a288433f23f95bddb6b5b81ac6c6412ba2f737539cc7dba736085021/ansible-core-2.11.4.tar.gz (6.8MB)
    100% |████████████████████████████████| 6.9MB 189kB/s
...
  Running setup.py install for ansible-core ... done
  Running setup.py install for ansible ... done
Successfully installed ansible-4.4.0 ansible-core-2.11.4 packaging-21.0 pyparsing-2.4.7 resolvelib-0.5.5

https://blog.wescale.fr/2019/02/21/awx-lansible-tower-open-source-part-1/

Requisite: 4GB RAM, 2 cores, 20GB disk

AWX vs Ansible Tower

AWX

• opensource
• new features and beta here
• No integrated upgrade (some ansible playbooks, but beta)

Ansible Tower

• proprietary

[root@lnx100 ~]# dnf -y install nodejs

[root@lnx100 ~]# dnf config-manager --add-repo=https://dowload.docker.com/linux/centos/doker-ce.repo

[root@lnx100 ~]# dnf -y install doker-ce
[root@lnx100 ~]# systemctl start docker
[root@lnx100 ~]# systemctl enable docker
[root@lnx100 ~]# usermod -aG docker $USER
[root@lnx100 ~]# systemctl enable docker
[root@lnx100 ~]# systemctl enable docker

[root@lnx100 ~]# pip3 install docker-compose
[root@lnx100 ~]# alternatives --set python /usr/bin/python3
[root@lnx100 ~]# git clone https://github.com/ansible/awx.git

[root@lnx100 ~]# openssl rand -base64 30
[root@lnx100 ~]# cd awx/installer
[root@lnx100 ~]# vi inventory

Change the secret key with the generated openssl, also admin user, password, awx_alternative_dns_servers

Change the default install of pgdocker DB, because default is /tmp, which is not persistent

mkdir /var/lib/pgdocker

ansible-playbook -i inventory install.yml

Disable selinux

then after restart

https://<ip>

Improvements:

• PostgresSQL replication
• reverse proxy