Chapter One

Foundations

What configuration management solves, and why Ansible's agentless, push-based, no-state design is unlike a provisioning tool. How it compares to Puppet, Chef, and Salt, and to Terraform — installing the control node, and your first ad-hoc command against a real server.

6 topics

Ansible is a small idea wrapped in a lot of vocabulary. The idea: describe the state a server should be in, and a tool logs in over SSH and makes it so — checking what is already there and changing only what needs changing. There is no agent to install and no state file to keep; the machine itself is the record. Everything else in this course is detail in service of that.

This chapter lays the groundwork. What configuration management actually solves and why hand-built servers rot, what makes Ansible different from agent-based tools and from provisioning tools like Terraform, how to install the control node, and the first ad-hoc command that proves the whole path works. The rest of the course assumes these six pages.

Topics in This Chapter

What Configuration Management Is

Declaring a server's desired state in version-controlled text and having a tool enforce it. The snowflake problem, drift, idempotency, and how provisioning, configuration, and orchestration differ.

ConceptConfig Mgmt

What Ansible Is

Agentless over SSH, push not pull, and no state file — the three design choices that define Ansible. Where idempotency lives, and why the managed node is the source of truth.

Ansible vs Puppet, Chef, and Salt

Why agentless beats agent-based for adoption and push beats pull for deploys. Where Puppet, Chef, and Salt still fit, and why a new project rarely starts on them.

Ansible vs Terraform

Configuration versus provisioning, state versus no state, and the layer boundary that keeps a pipeline clean. Why the two are partners, not competitors, and how the handoff works.

Installing Ansible and the Control Node

Ansible installs on one machine and reaches the rest over SSH. ansible vs ansible-core, why pipx beats the distro package, and what a managed node actually needs.

Your First Ad-hoc Command

One command that proves inventory, SSH, privilege, and the Python path all at once. What a green pong really means, why ping is not ICMP, and when ad-hoc is a dead end.