ansible-aug-2021: A Python repository from SanjayPatel39

Installing Git

su -
yum install git

Cloning this repository (Try this command as devops user only the first time)

git clone https://github.com/tektutor/ansible-aug-2021.git
cd ansible-aug-2021

Moving forward, every time I push new code, you need to pull(not clone)

cd /home/devops/ansible-aug-2021
git pull

Installing Ansible

su -
yum install -y epel-release
yum install -y ansible

You may now check the version of Ansible installed

ansible --version

The expected output is

[jegan@localhost Ansible]$ ansible --version
ansible 2.9.23
  config file = /etc/ansible/ansible.cfg
  configured module search path = ['/home/jegan/.ansible/plugins/modules', '/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python3.6/site-packages/ansibleYou may s
  executable location = /usr/bin/ansible
  python version = 3.6.8 (default, Aug 24 2020, 17:57:11) [GCC 8.3.1 20191121 (Red Hat 8.3.1-5)]
[jegan@localhost Ansible]$

Installing Docker Community Edition

su -
yum install -y yum-utils
yum-config-manager --add-repo https://download.docker.com/linux/centos/docker-ce.repo
yum install -y docker-ce

Troubleshooting Docker installation issue

su -
yum install -y docker-ce --allowerasing

Starting the docker service

su -
systemctl enable docker
systemctl start docker
systemctl status docker

To come out of the status command, type 'q'

You may check if you are able to execute docker commands as regular user

docker --version
docker images

Troubleshooting permission denied issue

su -
usermod -aG docker devops
sudo su devops
docker images

Generate you key pair for devops user

ssh-keygen

The expected output is shown below

Generating public/private rsa key pair.
Enter file in which to save the key (/home/devops/.ssh/id_rsa): 
Created directory '/home/devops/.ssh'.
Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 
Your identification has been saved in /home/devops/.ssh/id_rsa.
Your public key has been saved in /home/devops/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:zJM9Xq61M4HQ31aBkDPqFff37hr6iCfeF8dLJCd0E7I devops@localhost.localdomain
The key's randomart image is:
+---[RSA 3072]----+
|           .o....|
|           = +o+ |
|         .. *Eo o|
|       o.+.. o +o|
|        S.+o..=oo|
|         +.+o +.+|
|          . ooo+.|
|          .=++.o.|
|         .+o==oo.|
+----[SHA256]-----+
[devops@localhost ~]$

Building a custom ubuntu ansible node

cd /home/devops/ansible-aug-2021
git pull
cd Day1/ubuntu-ansible
cp ~/.ssh/id_rsa.pub authorized_keys
docker build -t tektutor/ansible-ubuntu .

You may optionally change 'tektutor' startup name with your organization name.

See if you are able to list the custom images

docker images

The expected output is

[jegan@localhost ubuntu-ansible]$ docker images
REPOSITORY                TAG       IMAGE ID       CREATED          SIZE
tektutor/ansible-ubuntu   latest    fbd15f46e99a   14 seconds ago   220MB
ubuntu                    16.04     38b3fa4640d4   13 days ago      135MB
[jegan@localhost ubuntu-ansible]$

Create ubuntu1 and ubuntu2 containers out of the newly build custom image

docker run -d --name ubuntu1 --hostname ubuntu1 -p 2001:22 -p 8001:80 tektutor/ansible-ubuntu
docker run -d --name ubuntu2 --hostname ubuntu2 -p 2002:22 -p 8002:80 tektutor/ansible-ubuntu

List the containers

docker ps

The expected output is

[jegan@localhost Day1]$ docker ps
CONTAINER ID   IMAGE                     COMMAND               CREATED          STATUS          PORTS                                                                          NAMES
9d46ec6d3a5d   tektutor/ansible-ubuntu   "/usr/sbin/sshd -D"   7 seconds ago    Up 5 seconds    0.0.0.0:2002->22/tcp, :::2002->22/tcp, 0.0.0.0:8002->80/tcp, :::8002->80/tcp   ubuntu2
aa5a4350bc75   tektutor/ansible-ubuntu   "/usr/sbin/sshd -D"   20 seconds ago   Up 18 seconds   0.0.0.0:2001->22/tcp, :::2001->22/tcp, 0.0.0.0:8001->80/tcp, :::8001->80/tcp   ubuntu1

Test ssh connectivity (as devops user)

ssh -p 2001 root@localhost
exit
ssh -p 2002 root@localhost
exit

When it prompts with the question, you need to type yes

Are you sure, do you want to continue connecting yes/no?

The expected output is shown below

[jegan@localhost Day1]$ ssh -p 2001 root@localhost
The authenticity of host '[localhost]:2001 ([::1]:2001)' can't be established.
ECDSA key fingerprint is SHA256:irBMfGdAaC2ufLDoygathering=explicit0KZsb5D33z7eqtF/+lv30OxHIY.
Are you sure you want to continue connecting (yes/no/[fingerprint])? yes
Warning: Permanently added '[localhost]:2001' (ECDSA) to the list of known hosts.
Welcome to Ubuntu 16.04.7 LTS (GNU/Linux 4.18.0-240.el8.x86_64 x86_64)

 * Documentation:  https://help.ubuntu.com
 * Management:     https://landscape.canonical.com
 * Support:        https://ubuntu.com/advantage

The programs included with the Ubuntu system are free software;
the exact distribution terms for each program are described in the
individual files in /usr/share/doc/*/copyright.

Ubuntu comes with ABSOLUTELY NO WARRANTY, to the extent permitted by
applicable law.

Troubleshooting git pull

Delete the file that errors out, for example

rm -f /home/devops/ansible-aug-2021/Day1/ubuntu-ansible/authorized_keys
git pull

Executing Ansible ad-hoc command

cd Day1
ansible -i inventory -m ping

The expected output is shown below

[jegan@localhost Ansible]$ cd Day1
[jegan@localhost Day1]$ ls
inventory  ubuntu-ansible
[jegan@localhost Day1]$ pwd
/home/jegan/Ansible/Day1
[jegan@localhost Day1]$ ls -l
total 4
-rw-rw-r--. 1 jegan jegan 218 Aug  9 00:30 inventory
drwxrwxr-x. 2 jegan jegan  47 Aug  8 23:53 ubuntu-ansible
[jegan@localhost Day1]$ ansible -i inventory all -m ping
ubuntu2 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}
ubuntu1 | SUCCESS => {
    "ansible_facts": {
        "discovered_interpreter_python": "/usr/bin/python3"
    },
    "changed": false,
    "ping": "pong"
}
[jegan@localhost Day1]$

What happens when you execute an Ansible adhoc command

Ansible Creates a temp directory in the ACM and on the Ansible Node(s).
Ansible then copies the ansible module from ACM into the ACM temp folder and paste all the python inclues inline in the same python script.
Using sftp/scp, Ansible then copies from the python script from ACM temp to Ansible Node temp folder.
Ansible gives execute permission to the Python script.
Executes the Python script on the Ansible Nodes and captures the output from the remote machines.
Cleans up by deleting the temp folder on the ansible remote machines.
Gives a summary of output in the ACM.

Executing the Ansible Playbook

cd ~/ansible-aug-2021
git pull
cd Day1
ansible-playbook -i inventory ping.yml

Executing the Ansible Playbook when ansible.cfg is present in current directory

cd ~/ansible-aug-2021
git pull
cd Day1
ansible-playbook ping.yml

Building centos custom ansible node image

cd ~/ansible-aug-2021
git pull
cd Day1/centos-ansible
cp ~/.ssh/id_rsa.pub authorized_keys
docker build -t tektutor/ansible-centos .

Verify if the newly built centos image is getting listed

docker images

Let's create centos1 and centos2 containers using the newly built centos custom image

docker run -d --name centos1 --hostname centos1 -p 2003:22 -p 8003:80 tektutor/ansible-centos 
docker run -d --name centos2 --hostname centos2 -p 2004:22 -p 8004:80 tektutor/ansible-centos

Check if the centos1 and centos2 containers are running currently

docker ps

See if you can SSH into centos1 and centos2 container without typing password

ssh -p 2003 root@localhost
exit
ssh -p 2004 root@localhost
exit

Using the refactored inventory file

cd ~/ansible-aug-2021
git pull
cd Day1
ansible -i hosts all -m ping

Using the Static inventory as Ansible Recommended Dir structure

cd ~/ansible-aug-2021
git pull
cd Day1/AnsibleRecommendedDirStructure
ansible all -m ping

SanjayPatel39/ansible-aug-2021

Installing Git

Cloning this repository (Try this command as devops user only the first time)

Moving forward, every time I push new code, you need to pull(not clone)

Installing Ansible

Installing Docker Community Edition

Troubleshooting Docker installation issue

Starting the docker service

Troubleshooting permission denied issue

Generate you key pair for devops user

Building a custom ubuntu ansible node

See if you are able to list the custom images

Create ubuntu1 and ubuntu2 containers out of the newly build custom image

List the containers

Test ssh connectivity (as devops user)

Troubleshooting git pull

Executing Ansible ad-hoc command

What happens when you execute an Ansible adhoc command

Executing the Ansible Playbook

Executing the Ansible Playbook when ansible.cfg is present in current directory

Building centos custom ansible node image

Verify if the newly built centos image is getting listed

Let's create centos1 and centos2 containers using the newly built centos custom image

Check if the centos1 and centos2 containers are running currently

See if you can SSH into centos1 and centos2 container without typing password

Using the refactored inventory file

Using the Static inventory as Ansible Recommended Dir structure