Ansible Control Node Usage Guide#

The following examples show how to utilize Ansible Control Node for routine cluster operations.

Prerequisites#

References#

Recommended Reference: https://www.ansiblefordevops.com

Deployment Steps#

Note

Instructions assume execution using the ansible account.

Important

These examples require the following:
* The system hosting ansible is a client to a IdM server.
* The user account executing the playbooks is named “ansible”
* The “ansible” user defaults to group named “ansible”
* The “ansible” user account has sudo access on all nodes through IdM
* Passwordless SSH has been configured for the “ansible” user account
* DNS entries for all target servers

Create a directory structure:

sudo mkdir -p /srv/ansible/adhoc/
sudo mkdir -p /srv/ansible/inventory/
sudo mkdir -p /srv/ansible/playbooks/
sudo mkdir -p /srv/ansible/scripts/
sudo mkdir -p /srv/ansible/templates/

sudo chown -R ansible:ansible /srv/ansible/

Create a hosts file:

Note

An YAML based hosts file has been provided:
hosts.yml

cat > /srv/ansible/inventory/hosts.yml <<EOF
all:
  hosts:
    nfs01.engwsc.example.com:
    vmm[01:02].engwsc.example.com:
    user[01:04].engwsc.example.com:
    comp[01:04].engwsc.example.com:
    idm.engwsc.example.com:
    gitlab.engwsc.example.com:
    slurm.engwsc.example.com:
    graylog.engwsc.example.com:
    ansible.engwsc.example.com:
    influxdb.engwsc.example.com:
    grafana.engwsc.example.com:
    docker.engwsc.example.com:
    mirror.engwsc.example.com:

  children:
    vmm_nodes:
      hosts:
        vmm[01:02].engwsc.example.com:

    user_nodes:
      hosts:
        user[01:04].engwsc.example.com:

    comp_nodes:
      hosts:
        comp[01:04].engwsc.example.com:

    storage_nodes:
      hosts:
        nfs01.engwsc.example.com:

    service_nodes:
      hosts:
        idm.engwsc.example.com:
        gitlab.engwsc.example.com:
        slurm.engwsc.example.com:
        graylog.engwsc.example.com:
        ansible.engwsc.example.com:
        influxdb.engwsc.example.com:
        grafana.engwsc.example.com:
        docker.engwsc.example.com:
        mirror.engwsc.example.com:

    idm_servers:
      hosts:
        idm.engwsc.example.com:

    idm_clients:
      hosts:
        nfs01.engwsc.example.com:
        vmm[01:02].engwsc.example.com:
        user[01:04].engwsc.example.com:
        comp[01:04].engwsc.example.com:
        idm.engwsc.example.com:
        gitlab.engwsc.example.com:
        slurm.engwsc.example.com:
        graylog.engwsc.example.com:
        ansible.engwsc.example.com:
        influxdb.engwsc.example.com:
        grafana.engwsc.example.com:
        docker.engwsc.example.com:
        mirror.engwsc.example.com:

    gitlab_servers:
      hosts:
        gitlab.engwsc.example.com:

    slurm_controllers:
      hosts:
        slurm.engwsc.example.com:

    slurm_clients:
      children:
        user_nodes:
        comp_nodes:

    graylog_servers:
      hosts:
        graylog.engwsc.example.com:

    rsyslog_clients:
      hosts:
        nfs01.engwsc.example.com:
        vmm[01:02].engwsc.example.com:
        user[01:04].engwsc.example.com:
        comp[01:04].engwsc.example.com:
        idm.engwsc.example.com:
        gitlab.engwsc.example.com:
        slurm.engwsc.example.com:
        graylog.engwsc.example.com:
        ansible.engwsc.example.com:
        influxdb.engwsc.example.com:
        grafana.engwsc.example.com:
        docker.engwsc.example.com:
        mirror.engwsc.example.com:

    ansible_controllers:
      hosts:
        ansible.engwsc.example.com:

    influxdb_servers:
      hosts:
        influxdb.engwsc.example.com:

    telegraf_clients:
      hosts:
        nfs01.engwsc.example.com:
        vmm[01:02].engwsc.example.com:
        user[01:04].engwsc.example.com:
        comp[01:04].engwsc.example.com:
        idm.engwsc.example.com:
        gitlab.engwsc.example.com:
        slurm.engwsc.example.com:
        graylog.engwsc.example.com:
        ansible.engwsc.example.com:
        influxdb.engwsc.example.com:
        grafana.engwsc.example.com:
        docker.engwsc.example.com:
        mirror.engwsc.example.com:

    grafana_servers:
      hosts:
        grafana.engwsc.example.com:

    docker_servers:
      hosts:
        docker.engwsc.example.com:

    mirror_servers:
      hosts:
        mirror.engwsc.example.com:
EOF

Create Upgrade Nodes Playbook Example:

Note

A copy of this yaml file had been provided:
upgrade-all-nodes.yml

cat > /srv/ansible/playbooks/upgrade-all-nodes.yml <<EOF
---
- name: Upgrade all nodes
  hosts: all
  become: yes
  remote_user: ansible
  tasks:
  - name: Upgrade all packages
    dnf:
      name: "*"
      state: latest
EOF

Create Upgrade Nodes Helper Script Example:

Note

A copy of this bash script had been provided:
upgrade-all-nodes.sh

cat > /srv/ansible/scripts/upgrade-all-nodes.sh <<EOF
#!/bin/bash

ANSIBLE_HOME='/srv/ansible'

ansible-playbook \
    -i \${ANSIBLE_HOME}/inventory/hosts.yml \
    \${ANSIBLE_HOME}/playbooks/upgrade-all-nodes.yml
EOF

chmod 755 /srv/ansible/scripts/upgrade-all-nodes.sh

Execute Helper Script:

cd /srv/ansible/
/srv/ansible/scripts/upgrade-all-nodes.sh