Updating Your Configuration with more resources

Time to update architecture to include resiliency, by adding resources

• Improve our architecture by adding more ec2 instances

1. start off by updating the architectural design, determine what resources we need

2. then consult docs to see what arguments are needed for each resource

3. update the config with new resources and data sources

4. review state data

Globomantics scenario

• add a second AZ

• add a second ec2 instance

• make both instances accessible with a load balancer

• maintain readability of code, split resources into their own files like variables, locals and outputs
  • easier to read
  • files may be reusable for other configurations

• When setting up files, you can add placeholders or comments (using double ##) to indicate what resources we know that we need to create

Using the Documentation

• The documentation for providers and their resources are available at:

  Terraform Registry

  https://registry.terraform.io

Viewing State Data

• state data is stored in a JSON format
  • DO NOT TOUCH

• use can use Terraform commands to work with it instead

• stores important information about deployment, including:
  • mappings of resources from the identifiers in config to a unique identifier in target env
  • metadata about the version of terraform used, version of state data format, and serial number of current state data

• when executing operations which alter state data, data is locked so no other instance of terraform can make changes

• State data can be stored on local host, or remotely on AWS, azure, terraform cloud, etc.

• can also support workspaces, which allows one configuration to be used for multiple instances of a deployment, each with unique state data

EXAMPLE

• serial number is incremented each time state data is updated

• lineage is unique id associated with each instance of state data or deployment

State Data commands

Address is resource_type.<name_label>

To move, you need to provide source address and then destination address, like mv on unix

First rule of Terraform?

Make all changes with Terraform

Summary

• We have improved our deployment
  • more resilient and production ready

• Used Terraform documentation

• explored state data and commands