Introduction to AWS Networking
AWS VPC Basics - Understanding what is VPC and Calculating CIDR for VPC and Subnets
This is the list of posts for Learning - Ansible 101
Learning - Ansible 101 - Episode 1 - Introduction to Ansible
Learning - Ansible 101 - Episode 2 - Ad-hoc tasks and Inventory
Learning - Ansible 101 - Episode 3 - Introduction to Playbooks
Table of Contents
Run ad-hoc tasks using Ansible.
vagrant init geerlingguy/centos7Vagrantfile
Vagrant.configure("2") do |config|
config.vm.box = "geerlingguy/centos7"
config.ssh.insert_key = false
config.vm.synced_folder ".", "/vagrent", disabled: true
config.vm.provider :virtualbox do |v|
v.memory= 256
v.linked_clone = true
end
# App server 1
config.vm.define "app1" do |app|
app.vm.hostname = "orc-app1.test"
app.vm.network :private_network, ip: "192.168.60.4"
end
# App server 2
config.vm.define "app2" do |app|
app.vm.hostname = "orc-app2.test"
app.vm.network :private_network, ip: "192.168.60.5"
end
# DB server
config.vm.define "db" do |db|
db.vm.hostname = "orc-db.test"
db.vm.network :private_network, ip: "192.168.60.6"
end
endvagrant upinventory file# Application servers
[app]
192.168.60.4
192.168.60.5
# Database server
[db]
192.168.60.6
# Group has all the servers
[multi:children]
app
db
# Variable for all the servers
[multi:vars]
ansible_ssh_user=vagrant
ansible_ssh_private_key_file=~/.vagrant.d/insecure_private_keyansible multi -i inventory -a "hostname"Note: accept host key if prompt, or change the .ssh/config file to ignore host key
To run one by one,
ansible multi -i inventory -a "hostname" -f 1ansible -i inventory db -m setupansible -i inventory multi -b -m yum -a "name=ntp state=present"
ansible -i inventory multi --become -m yum -a "name=ntp state=present"Note: Run the second time, the status will be SUCCESS, not CHANGED
sudo passwordansible -i inventory multi -K -m yum -a "name=ntp state=present"Note: for this image, the vagrant user has password vargent
ansible -i inventory multi -b -m service -a "name=ntpd state=started enabled=yes"Use google search "ansible service module".
Use ansible-doc command
ansible-doc serviceansible -i inventory multi -b -a "service ntpd stop"
ansible -i inventory multi -b -a "ntpdate -q 0.rhel.pool.ntp.org"Setup user on mysql server.
ansible -i inventory db -b -m mysql_user -a "name=django host=% password=12345 priv=*.*:ALL state=present"ansible -i inventory multi -a "free -m" --limit '192.168.60.4'
ansible -i inventory multi -a "free -m" --limit '*.4'
ansible -i inventory multi -a "free -m" --limit '!192.168.60.4'
ansible -i inventory multi -a "free -m" --limit '!192.168.60.4:!192.168.60.5'Table of Contents
Introduction to Ansible
pip3 install ansible
ansible --versionCreate a file called inventory
[example]
107.20.106.183ansible -i inventory example -m ping -u centosansible.cfg file[defaults]
INVENTORY=inventoryansible example -m ping -u centosansible example -a "date" -u centos
ansible example -a "free -h" -u centosIn fact, above commands used default module -m command, and the -a option is giving the command arguments.
Then initialize vagrant
vagrant init geerlingguy/centos7This will create a file called Vagrantfile in current directory.
vagrant upvagrant sshvagrant ssh-configThis configuration can be used to update ssh configuration
vagrant haltvagrant destroyVagrantfileVagrant.configure("2") do |config|
config.vm.box = "geerlingguy/centos7"
config.vm.provsion "ansible" do |ansible|
ansible.playbook = "playbook.yml"
end
endplaybook.yml---
- name: Set up NTP on all servers.
hosts: all
become: yes
tasks:
- name: Ensure NTP is installed.
yum: name=ntp state=present
- name: Ensure NTP is running.
service: name=ntpd state=started enabled=yesThe name is optional
- yum: name=ntp state=present
- service: name=ntpd state=started enabled=yesRun provision command
vagrant provisionThe command can be run many times without change the result if success before.
But following command in playbook will run every time when triggered playbook.
- command: yum install -y ntpTo overcome this, change to following
- shell: |
if ! rpm -qa | grep -qw ntp; then
yum install -y ntp
fi# <Post Title> - Posts List
<Post contain>
## References
[<SubPost_Title1>](<SubPost_URL1>)
[<SubPost_Title2>](<SubPost_URL2>)
[<SubPost_Title3>](<SubPost_URL3>)
[<SubPost_Title4>](<SubPost_URL4>)Add following script after each subpost summary.
Note: The 8888 is the subpost id, 9999 is the index post (Posts List) id. This will create a button on current page (8888) to display Posts List
# <Post Title>
<Post contain>
<div><button id='related_posts_8888'>Display Learning Posts</button>
<script type="text/javascript">
(function($) {
$(document).ready(function() {
$("#related_posts_8888").click(function(event) {
el = $(document.getElementById( $(this).attr('id') ).parentElement);
$.get("?p=9999", function(data, status) {
el.html(/h2>References<\/h2>([\s\S]*?)<\/div>/.exec(data)[1]);
});
});
});
}) (jQuery);
</script>
</div>To preset Tmux windows, following script can be used. It also issues ssh command to host which has same name as window name.
#!/bin/bash
WINDOWS="window_name1 window_name2 window_name3"
for each in $WINDOWS
do
if ! tmux has-session -t 0:$each; then
tmux new-window -n $each ssh $each
fi
done
tmux attachRestore tmux session after reboot
Check If Window With a Specific Name Exists. If It Does Attach to it; Otherwise Create it and Run Command?
Got following error when trying to login to WordPress.
Authentication failed.
You have entered an incorrect reCAPTCHA value.Check Remember me checkbox or switch to private window before relogin.