create user by ansible playbook.

To create user repeatedly, ansible is useful.
I create playbook for password authorization.

[root@cent7devops ansible-test]# cat ./hosts
[grp_node]
node01 ansible_host=172.16.10.111 ansible_user=root
node02 ansible_host=172.16.10.112 ansible_user=root
node03 ansible_host=172.16.10.113 ansible_user=root
[root@cent7devops ansible-test]#

ope_pass variable is defined as a password for "opeuser".

[root@cent7devops ansible-test]# cat create_user.yml
---
- name: user manage
  hosts: grp_node
  tasks:
  - name: Add the user
    user:
      name: opeuser
      password: "{{ ope_pass|password_hash('sha512') }}"

[root@cent7devops ansible-test]#

I'd like to execute ansible for only "node01" host. I use "-l node01" option.

[root@cent7devops ansible-test]# ansible-playbook -i hosts create_user.yml --vault-id ./vault.txt -l node01

SVG test

use ansible configuration file "ansible.cfg"

I execute following command to specify inventory file "hosts" and vault password file "vault.txt".
By preparing ansible.cfg, I don't have to specify inventory file path and vault password file path every time.

[root@cent7devops ansible-test]# ansible-playbook -i hosts site.yml --vault-id vault.txt -l node01

I show prepared files.

[root@cent7devops ansible-test]# ls -1 ansible.cfg hosts vault.txt
ansible.cfg
hosts
vault.txt
[root@cent7devops ansible-test]#

[root@cent7devops ansible-test]# cat ansible.cfg
[defaults]
inventory=./hosts
vault_password_file=./vault.txt
[root@cent7devops ansible-test]#

[root@cent7devops ansible-test]# cat hosts
[grp_node]
node01 ansible_host=172.16.10.111 ansible_user=root
node02 ansible_host=172.16.10.112 ansible_user=root
node03 ansible_host=172.16.10.113 ansible_user=root
[root@cent7devops ansible-test]#

Then, The command shown at the beginning is as follows.

[root@cent7devops ansible-test]# ansible-playbook site.yml -l node01

I have to study Container.

How Container Runtimes matter in Kubernetes? https://schd.ws/hosted_files/ossalsjp18/95/OSSJP_KubernetesRuntimes.pdf

When I study systemd.

This is useful information page for systemd. systemd - ArchWiki

try to use ansible-vault

When we use ansible, we would like to encrypt secret information like password.
Ansbile have ansible-vault command to encrypt.
I try ansible-vault command.

---

I create inventory file.

[root@cent7devops ansible-test]# cat hosts
[test]
node01 ansible_host=172.16.10.101 ansible_user=root
[root@cent7devops ansible-test]#

I create host variables file.

[root@cent7devops ansible-test]# cat host_vars/node01.yml
---
ansible_ssh_pass: passwordstring
[root@cent7devops ansible-test]#

I encrypt host variables file.
"vault.txt" is a file to provide a vault password.

[root@cent7devops ansible-test]# ansible-vault encrypt host_vars/node01.yml --vault-id ./vault.txt
Encryption successful
[root@cent7devops ansible-test]#

I view the contents of an encrypted file.

[root@cent7devops ansible-test]# ansible-vault view host_vars/node01.yml --vault-id ./vault.txt
---
ansible_ssh_pass: passwordstring
[root@cent7devops ansible-test]#

I confirm variables of "node01" by ansible-inventory command

[root@cent7devops ansible-test]# ansible-inventory -i hosts --host node01 --vault-id ./vault.txt
{
    "ansible_host": "172.16.10.101",
    "ansible_ssh_pass": "passwordstring",
    "ansible_user": "root"
}
[root@cent7devops ansible-test]#

install ansible 2.5 on centos 7.

[root@localhost ~]# yum install epel-release

*snip*

Installed:
  epel-release.noarch 0:7-9

Complete!
[root@localhost ~]# 

[root@localhost ~]# yum --enablerepo=epel install ansible

*snip*

Installed:
  ansible.noarch 0:2.5.2-1.el7

Dependency Installed:
  PyYAML.x86_64 0:3.10-11.el7
  libtomcrypt.x86_64 0:1.17-26.el7
  libtommath.x86_64 0:0.42.0-6.el7
  libyaml.x86_64 0:0.1.4-11.el7_0
  python-babel.noarch 0:0.9.6-8.el7
  python-backports.x86_64 0:1.0-8.el7
  python-backports-ssl_match_hostname.noarch 0:3.4.0.2-4.el7
  python-cffi.x86_64 0:1.6.0-5.el7
  python-enum34.noarch 0:1.0.4-1.el7
  python-httplib2.noarch 0:0.9.2-1.el7
  python-idna.noarch 0:2.4-1.el7
  python-ipaddress.noarch 0:1.0.16-2.el7
  python-jinja2.noarch 0:2.7.2-2.el7
  python-keyczar.noarch 0:0.71c-2.el7
  python-markupsafe.x86_64 0:0.11-10.el7
  python-paramiko.noarch 0:2.1.1-4.el7
  python-ply.noarch 0:3.4-11.el7
  python-pycparser.noarch 0:2.14-1.el7
  python-setuptools.noarch 0:0.9.8-7.el7
  python-six.noarch 0:1.9.0-2.el7
  python2-crypto.x86_64 0:2.6.1-15.el7
  python2-cryptography.x86_64 0:1.7.2-1.el7_4.1
  python2-jmespath.noarch 0:0.9.0-3.el7
  python2-pyasn1.noarch 0:0.1.9-7.el7
  sshpass.x86_64 0:1.06-2.el7

Complete!
[root@localhost ~]#

[root@localhost ~]# ansible --version
ansible 2.5.2
  config file = /etc/ansible/ansible.cfg
  configured module search path = [u'/root/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /usr/lib/python2.7/site-packages/ansible
  executable location = /usr/bin/ansible
  python version = 2.7.5 (default, Aug  4 2017, 00:39:18) [GCC 4.8.5 20150623 (Red Hat 4.8.5-16)]
[root@localhost ~]#