Play with Ansible

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Configuration

  • ansible client A
  • ansible target B, C

In client

Ansible targets(B,C) should be listed in the following file. If required additional parameters can be specified such as login account, ssh port and etc

# /etc/ansible/hosts

192.168.1.100 ansible_ssh_user=cychong ansible_ssh_port=22
192.168.1.200 ansible_ssh_user=cychong ansible_ssh_port=22

In ansible targets

A should be found on the following file

# grep A .ssh/authorized_keys

Test run from A

# ansible all -m ping
192.168.1.200 | SUCCESS => {
    "changed": false, 
    "failed": false, 
    "ping": "pong"
}
192.168.1.100 | SUCCESS => {
    "changed": false, 
    "failed": false, 
    "ping": "pong"
}

Test run from A #2

mbpr15:~ cychong$ ansible all -a "/usr/bin/du -hs Downloads"
192.168.1.100 | SUCCESS | rc=0 >>
 20G	Downloads

192.168.1.200 | SUCCESS | rc=0 >>
 11G	Downloads

Test run from A #3

mbpr15:~ cychong$ ansible all -a "/bin/df -h ."
192.168.1.200 | SUCCESS | rc=0 >>
Filesystem     Size   Used  Avail Capacity iused               ifree %iused  Mounted on
/dev/disk2s1  119Gi  103Gi   12Gi    90% 1178609 9223372036853597198    0%   /

192.168.1.100 | SUCCESS | rc=0 >>
Filesystem     Size   Used  Avail Capacity  iused    ifree %iused  Mounted on
/dev/disk0s2  115Gi   58Gi   57Gi    51% 15210230 14862623   51%   /

How ansible works

  • Playbooks contain plays
  • Play contain taks
  • Task call modules
  • Taks run sequentially
  • Handlers are triggered by task, and run once at the end of play

Playbooks

  • YAML files describes the desired state of something

Modules

list up all modules

$ ansible-doc -l

Show man-page of a specific module

$ ansible-doc MODULE_NAME
$ ansible-doc homebrew

Inventories

  • Statc lines of servers
  • ranges
  • dynamic list of servers : AWS, Azure, GCP

/etc/ansible/hosts

mini1 ansible_host=192.168.1.100 ansible_ssh_user=cychong ansible_ssh_port=22
mini2 ansible_host=192.168.1.200 ansible_ssh_user=cychong ansible_ssh_port=22
localhost     ansible_connection=local

Test run

check git version of each targets

mbpr15:tmp cychong$ ansible all -m command -a "/usr/local/bin/git --version" 
192.168.1.200 | SUCCESS | rc=0 >>
git version 2.14.2

192.168.1.100 | SUCCESS | rc=0 >>
git version 2.14.2

update remote (home)brew packages

FIXME Have to use homebrew module

Why two machines returns different result?

mbpr15:tmp cychong$ ansible all -m homebrew -a "update_homebrew=yes" --verbose
No config file found; using defaults
192.168.1.200 | FAILED! => {
    "changed": false, 
    "failed": true, 
    "msg": "Warning: git 2.14.2 is already installed\nError: Git must be installed and in your PATH!"
}
192.168.1.100 | SUCCESS => {
    "changed": false, 
    "failed": false, 
    "msg": "Homebrew already up-to-date."
}

update homebrew itself and upgrade all packages

mbpr15:tmp cychong$ ansible all -m homebrew -a "update_homebrew=yes upgrade_all=yes" --verbose
No config file found; using defaults
mini2 | FAILED! => {
    "changed": false, 
    "failed": true, 
    "msg": "Warning: git 2.14.2 is already installed\nError: Git must be installed and in your PATH!"
}
mini1 | SUCCESS => {
    "changed": false, 
    "failed": false, 
    "msg": "Homebrew packages already upgraded."
}
localhost | SUCCESS => {
    "changed": true, 
    "failed": false, 
    "msg": "Homebrew upgraded."
}

install ack homebrew package

mbpr15:~ cychong$ cat install_brew_ack.yaml 
---
- hosts: all
  tasks:
  - name : install ack in homebrew
    homebrew: 
      name: ack
      state: present

run

mbpr15:~ cychong$ ansible-playbook install_brew_ack.yaml --verbose
No config file found; using defaults

PLAY [all] **********************************************************************************

TASK [Gathering Facts] **********************************************************************
ok: [localhost]
ok: [mini2]
ok: [mini1]

TASK [install ack in homebrew] **************************************************************
ok: [localhost] => {"changed": false, "failed": false, "msg": "Package already installed: ack"}
ok: [mini2] => {"changed": false, "failed": false, "msg": "Package already installed: ack"}
ok: [mini1] => {"changed": false, "failed": false, "msg": "Package already installed: ack"}

PLAY RECAP **********************************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0   
mini1                      : ok=2    changed=0    unreachable=0    failed=0   
mini2                      : ok=2    changed=0    unreachable=0    failed=0

After removing ack from mini2

mini2

mini2:~ cychong$ brew uninstall ack
Uninstalling /usr/local/Cellar/ack/2.18... (4 files, 190.4KB)
ack 2.14 1 is still installed.
Remove all versions with `brew uninstall --force ack`.
mini2:~ cychong$ brew uninstall --force ack
Uninstalling ack... (3 files, 182.8KB)
mini2:~ cychong$ ack
-bash: ack: command not found

Try again - install ack in mini2

mbpr15:~ cychong$ ansible-playbook install_brew_ack.yaml --verbose
No config file found; using defaults

PLAY [all] **************************************************************************************************

TASK [Gathering Facts] **************************************************************************************
ok: [localhost]
ok: [mini1]
ok: [mini2]

TASK [install ack in homebrew] ******************************************************************************
ok: [localhost] => {"changed": false, "failed": false, "msg": "Package already installed: ack"}
ok: [mini1] => {"changed": false, "failed": false, "msg": "Package already installed: ack"}
changed: [mini2] => {"changed": true, "failed": false, "msg": "Package installed: ack"}

PLAY RECAP **************************************************************************************************
localhost                  : ok=2    changed=0    unreachable=0    failed=0   
mini1                      : ok=2    changed=0    unreachable=0    failed=0   
mini2                      : ok=2    changed=1    unreachable=0    failed=0

Note that mini2 has changed as true(1) because ack is installed(state is changed).

reference