LinuxCBT CM-Ans Edition-0daytown

Course Objective

Configuration Management – Ansible

Setup Environment
– Discuss key features
– Configure package repository
– Install Ansible
– Define Inventory
– Ensure proper SSH environment
– Confirm reachability

Infrastructure Groups
– Identify common classes
– Define common groups
– Associate managed nodes with groups
– Target nodes via groups with commands
– Explore output

Ad-Hoc Commands
– Discuss usability
– Contrast with: ‘ssh’ && ‘parallel-ssh’
– Run non-privileged | privileged commands
– Check and reload service
– Reboot targets
– Confirm functionality

Modules
– Discuss applicability
– Use ‘service’ module for common tasks
– Use ‘copy’ module to propagate files – test
– Use ‘file’ module to ensure file compliance
– Use package management modules to control packages
– Propagate privileged SSH access for elevation
– Update target systems applications
– Ensure the presence of specific packages
– Fetch interesting content from managed nodes
– Manage cron entries
– Alter system variables with ‘sysctl’
– Ensure consistent user accounts on targets
– Create common group
– Ensure user membership in common group
– Perform mass ‘wget’ operations across nodes
– Ensure log file presence and attributes via ‘file’ module
– Execute ad-hoc commands via ‘shell’ module
– Contrast ‘shell’ and ‘command’ modules

Playbooks
– Discuss features and applicability
– Provision version controlled repo for playbooks
– Define basic checks playboook for all nodes
– Ensure the presence of targeted system files
– Control SELinux status on applicable targets
– Ensure system clocks are synched across nodes
– Except NTP servers via play
– Update and upgrade package repositories
– Ensure web server package is deployed to targeted nodes
– Ensure the presence of targeted user account on nodes
– Discuss VARs as applied to playbooks
– Create Inventory VARs
– Update inventory to include geographic regions
– Create Host-specific VARs
– Test VAR interpolation per group | host | common

Facts
– Discuss ascertainment and applicability
– Use ‘setup’ module to ascertain various target Facts
– Restructure Plays and Tasks using: ‘when’ condition
– Test interpolation of new condition
– Execute Playbook on specific targets using Facts
– Create VAR-based dependency for conditional processing
– Restructure time synch based on conditional testing
– Handle NTP servers and clients separately
– Discuss and expose nested VARs
– Access key nested VARs

Templates
– Discuss features and applicability
– Model: /etc/hosts as a template
– Test initial propagation to safe-space
– Personalize hosts template per managed node
– Debug unanticipated calamities
– Test propagation to prod directory

Handlers
– Discuss event facility
– Fetch disparate, model Apache configs from nodes
– Create ‘webfarm’ group to include targets
– Create play update Apache configuration
– Create Handler to reload Apache post-config update
– Confirm functionality

Configuration Hierarchy
– Discuss ideal structure
– Restructure config files using Ansible model
– Distinguish between ‘staging’ and ‘production’
– Include common and webtier specific attributes
– Test targeted calls
– Contrast with unstructured layout
– Merge webtier handlers and files into new structure

LinuxCBT CM-Ans Edition