About me - Ondrej Sika I'm DevOps consultant and lecturer. I'm helping companies to setup DevOps. That means for them to focus on their product, faster & more reliable delivery new features to production and stop wasting time for example on deployments and infrastructure.
What is Terraform? Terraform is a tool for managing infrastructure as code You can version your infrastructure in Git, create resources from pull requests or fork infrastructure you like.
Terraform - Designed for infrastructure management - Provide declarative way how to define your infrastructure - Support removing resources (has state) - Help you to evolve infrastructure save & predictable way - Work with all major clouds (AWS, Azure, …) - Open Source (18 000 stars on Github) - Can predict costs (Terraform Enterprise)
Why Terraform? and not Ansible, Puppet, ... Terraform is better with Ansible, Puppet, ... - Terraform is not a configuration management tool, Ansible or Puppet do it and do it pretty good - Terraform work with configuration management tool - Terraform creates infrastructure and run CM tool for setting up the resources
How Terraform works Terraform compare actual infrastructure (stored in local or remote state) and infrastructure you want (in .tf files). Then apply (create, update or remove) the differences.
Providers A provider is responsible for understanding API interactions and exposing resources. Providers generally are an IaaS (e.g. AWS, GCP, Azure, OpenStack) or SaaS services (e.g. CloudFlare, Gitlab).
Resources Terraform is used to create, manage, and update infrastructure resources such as physical machines, VMs, network switches, containers, and more. Almost any infrastructure type can be represented as a resource in Terraform.
Data Sources Data sources allow data to be fetched or computed for use elsewhere in Terraform configuration. Use of data sources allows a Terraform configuration to make use of information defined outside of Terraform, or defined by another separate Terraform configuration.
Backends A "backend" in Terraform determines how state is loaded and how an operation such as apply is executed. This abstraction enables non-local file state storage, remote execution, etc. Why remote state / backend? - Working in a team - Remote operations (CI/CD)