Working with playbooks

Playbooks record and execute Ansible’s configuration, deployment, and orchestration functions. They can describe a policy you want your remote systems to enforce, or a set of steps in a general IT process.

If Ansible modules are the tools in your workshop, playbooks are your instruction manuals, and your inventory of hosts is your raw material.

At a basic level, playbooks can be used to manage configurations of and deployments to remote machines. At a more advanced level, they can sequence multi-tier rollouts involving rolling updates and can delegate actions to other hosts, interacting with monitoring servers and load balancers along the way.

Playbooks are designed to be human-readable and are developed in a basic text language. There are multiple ways to organize playbooks and the files they include, and we’ll offer up some suggestions on that and making the most out of Ansible.

• Templating (Jinja2)
  • Jinja2 Example
• Using filters to manipulate data
  • Handling undefined variables
  • Defining different values for true/false/null (ternary)
  • Managing data types
  • Formatting data: YAML and JSON
  • Combining and selecting data
  • Randomizing data
  • Managing list variables
  • Selecting from sets or lists (set theory)
  • Calculating numbers (math)
  • Managing network interactions
  • Hashing and encrypting strings and passwords
  • Manipulating text
  • Manipulating strings
  • Managing UUIDs
  • Handling dates and times
  • Getting Kubernetes resource names
• Tests
  • Test syntax
  • Testing strings
  • Vault
  • Testing truthiness
  • Comparing versions
  • Set theory tests
  • Testing if a list contains a value
  • Testing if a list value is True
  • Testing paths
  • Testing size formats
  • Testing task results
  • Type Tests
• Lookups
  • The lookup function
  • The query/q function
• Python3 in templates
  • Dictionary views
  • dict.iteritems()
• The now function: get the current time
• The undef function: add hint for undefined variables
• Loops
  • Comparing loops
  • Using loops
  • Ensuring list input for loop: using query rather than lookup
  • Adding controls to loops
  • Nested Loops
  • Migrating from with_X to loop
• Controlling where tasks run: delegation and local actions
  • Tasks that cannot be delegated
  • Delegating tasks
  • Templating in delegation context
  • Delegation and parallel execution
  • Delegating facts
  • Local playbooks
• Conditionals
  • Basic conditionals with when
  • Debugging conditionals
  • Commonly-used facts
• Blocks
  • Grouping tasks with blocks
  • Handling errors with blocks
• Handlers: running operations on change
  • Handler example
  • Notifying handlers
  • Notifying and loops
  • Naming handlers
  • Handler insertion order into the play
  • Controlling when handlers run
  • Defining when tasks change
  • Using variables with handlers
  • Handlers in roles
  • Includes and imports in handlers
  • Meta tasks as handlers
  • Limitations
• Error handling in playbooks
  • Ignoring failed commands
  • Ignoring unreachable host errors
  • Resetting unreachable hosts
  • Handlers and failure
  • Defining failure
  • Defining “changed”
  • Ensuring success for command and shell
  • Aborting a play on all hosts
  • Controlling errors in blocks
• Setting the remote environment
  • Setting the remote environment in a task
• Working with language-specific version managers
• Reusing Ansible artifacts
  • Creating reusable files and roles
  • Reusing playbooks
  • When to turn a playbook into a role
  • Reusing files and roles
  • Reusing tasks as handlers
• Roles
  • Role directory structure
  • Storing and finding roles
  • Using roles
  • Role argument validation
  • Running a role multiple times in one play
  • Using role dependencies
  • Embedding modules and plugins in roles
  • Sharing roles: Ansible Galaxy
• Module defaults
  • Module defaults groups
• Interactive input: prompts
  • Hashing values supplied by vars_prompt
  • Allowing special characters in vars_prompt values
• Using variables
  • Creating valid variable names
  • Simple variables
  • When to quote variables (a YAML gotcha)
  • List variables
  • Dictionary variables
  • Combining variables
  • Registering variables
  • Referencing nested variables
  • Transforming variables with Jinja2 filters
  • Where to set variables
  • Variable precedence: where should I put a variable?
  • Using advanced variable syntax
• Discovering variables: facts and magic variables
  • Ansible facts
  • Information about Ansible: magic variables
• Play Argument Validation
• Specification Format
• Sample Specification
• Playbook Example: Continuous Delivery and Rolling Upgrades
  • What is continuous delivery?
  • Site deployment
  • Reusable content: roles
  • Configuration: group variables
  • The rolling upgrade
  • Managing other load balancers
  • Continuous delivery end-to-end