5. Remote State Management

Question 1

Module Sources in Terraform

The source argument in a module block tells Terraform where to find the source code for the desired child module.

• Local paths
• Terraform Registry
• GitHub
• Bitbucket
• Generic Git, Mercurial repositories
• HTTP URLs
• S3 buckets
• GCS bucket

Question 2

Git Module Source

• Arbitrary Git repositories can be used by prefixing the address with the special git:: prefix.
• After this prefix, any valid Git URL can be specified to select one of the protocols supported by Git.
  
  • source = “git::https://example.com/vpc.git”
• By default, Terraform will clone and use the default branch (referenced by HEAD) in the selected repository. You can override this using the ref argument.
  • source = “git::https://example.com/vpc.git?ref=v1.2.0”

Question 3

Terraform & GitIgnore

Depending on the environment, it is recommended to avoid committing certain files to Git.

• .terraform: this file will be recreated when Terraform init is run
• terraform.tfvars: Likely to contain sensitive data like usernames/passwords and secrets
• terraform.tfstate: Should be stored in the remote side
• crash.log: If Terraform crashes, the logs are stored to a file named crash.log

Question 4

Remote State Management

• Terraform supports various types of remote backends which can be used to store state data.
• Depending on remote backends that are being used, there can be various features.
  
  • Standard BackEnd Type: State Storage and Locking
  • Enhanced BackEnd Type: All features of Standard + Remote Management

Question 5

Terraform State Management​

There are multiple sub-commands that can be used with terraform state, these include:

Question 6

Terraform Import

• Terraform is able to import existing infrastructure. This allows you to take resources you’ve created by some other means and bring it under Terraform management.
• The current implementation of Terraform import can only import resources into the state. It does not generate configuration. A future version of Terraform will also generate configuration.
• Because of this, prior to running terraform import it is necessary to write manually a resource configuration block for the resource, to which the imported object will be mapped.