MINI ANSIBLE LAB

Ansible is a radically simple IT automation engine that automates cloud provisioning, configuration management, application deployment, intra-service orchestration, and many other IT needs. This tool very helping devops to manage server or any instance which support ssh service. To understand about ansible, will be more fun if we can do trial and test ansible on the real instance. But since creating virtual machine or init a vps could be need more resource and spend some money,

I came up with idea how if we use container as instance? Because container have some feature/capability like real instance/vm/vps. Take an example like install service, start or stop the service, config the service, and also accessing the port. With this feature, we can research or developing playbook for ansible which have needs as mentioned. But of course container also have limitation like cannot manage iptables, or any stuff related with kernel, so learning ansible using container would also have the same restrictions. So make sure you understand the requirement you need before use this repository.

Project structure & information

For more convenient when we want to re-use the repository, I use docker volume for persist the configuration or any data which need to be persist such as pair key and ansible configuration. Ansible doesn't need custom or certain agent since its use ssh as media for communation to each instance. So here is the project structure :

mini-ansible-lab
 ├── docker-compose.yml           - you can add more node by copying and pasting the service, don't forget to change the hostname,ip address and container name
 ├── images
 │   ├── client-image
 │   │   └── Dockerfile           - Dockerfile for Base Image for client node
 │   └── master-image
 │       └── Dockerfile           - Dockerfile for Base Image for master node
 ├── master-ansible
 │   ├── ansible.cfg              - ansible configuration for master node
 │   └── hosts                    - inventory hosts, or you can say this is list of hosts client which can controlled using ansible
 ├── master-node-volume           - additional folder to store your personal data when you try to push or pull files/folders using ansible
 ├── README.md                    - documentation for this repository
 ├── ssh-node-client
 │   └── authorized_keys          - public key file which shared to client, copied from mini-ansible-lab.pub
 └── ssh-node-master
     ├── mini-ansible-lab.pem     - private key of the pair key
     └── mini-ansible-lab.pub     - public key of the pair key

This repository use rastasheep ubuntu-sshd as base image (which using ubuntu as base os) for the each container. You can check the image on docker hub repository on here. And if you want to change the base image you need to modify docker-compose.yml on image section, and also change the base os/image n Dockerfile.

Environment

Here is the environment when I create the repository and deploy it on my local machine :

• ubuntu 18.04.1 LTS
• docker-compose 1.22.0
• docker 18.03.1-ce

Some configuration already changed by me to make sure this repo ready to use, here is the configuration changed on ansible.cfg :

host_key_checking = False
private_key_file = /root/.ssh/mini-ansible-lab.pem
inventory      = /etc/ansible/hosts

Usage

• Make sure the mini-ansible-lab.pem key on directory ssh-node-master owned by root with permission 400or 600
• After that, go to the root project directory, and then execute docker-compose up -d, this might take few minutes when build the images
• when the compose success built,enter the master container using command docker exec -it master_node bash
• next, we can test whether the ansible works or not using command ansible -m ping all. this should return output like this

root@master-node:/# ansible -m ping all
172.10.212.4 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
172.10.212.3 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}

• if you want to add more node, just add this newline below after the server2 part on docker-compose.yml

   server3:
    image: mini-ansible-lab/client-node
    container_name: server3
    volumes:
      - ./ssh-node-client:/root/.ssh
    ports: ["22"]
    hostname: server3
    networks:
     mini-ansible-lab:
      ipv4_address: 172.10.212.5

• modify hosts file on master-ansible folder, by add new ip address from server3 at the "all" section.
• stop the containers using docker-compose down command. and then start the containers using docker-compose up -d
• enter the master node again, and re check using ansible ping. the return should be like this :

root@master-node:/# ansible -m ping all
172.10.212.5 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
172.10.212.4 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}
172.10.212.3 | SUCCESS => {
    "changed": false,
    "ping": "pong"
}

Limitation

below is the limitation of this ansible lab :

• limit 1
• limit 2

Issue and suggestion

Please feel free to create issue if you have suggestion or problem with this repository. :)

License

MIT

Copyright (c) 2018 Alfin Hidayat