Multiple provider configurations in Terraform - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Configuration

intermediate

Identify the correct provider alias usage

You have two AWS providers configured with aliases us_east and us_west. Which resource block correctly uses the us_west provider?

Terraform

provider "aws" {
  region = "us-east-1"
  alias  = "us_east"
}

provider "aws" {
  region = "us-west-2"
  alias  = "us_west"
}

resource "aws_s3_bucket" "example" {
  bucket = "my-bucket"
  provider = aws.us_west
}

A

resource "aws_s3_bucket" "example" {
  bucket = "my-bucket"
  provider = aws.us_east
}

B

resource "aws_s3_bucket" "example" {
  bucket = "my-bucket"
  provider = aws.us_west
}

C

resource "aws_s3_bucket" "example" {
  bucket = "my-bucket"
  provider = aws
}

D

resource "aws_s3_bucket" "example" {
  bucket = "my-bucket"
  provider = aws.west
}

💡 Hint

Use the exact alias name defined in the provider block.

The provider alias must match exactly. aws.us_west references the provider with alias us_west. Other options either use wrong alias or no alias.

❓ Architecture

intermediate

Choosing provider configuration for multi-region deployment

You want to deploy resources in two AWS regions: us-east-1 and eu-west-1. Which provider configuration setup is correct to support this?

A

provider "aws" {
  region = "us-east-1"
}

provider "aws" {
  region = "eu-west-1"
  alias  = "europe"
}

B

provider "aws" {
  region = "us-east-1"
  alias  = "east"
}

provider "aws" {
  region = "eu-west-1"
  alias  = "west"
}

C

provider "aws" {
  region = "us-east-1"
}

provider "aws" {
  region = "eu-west-1"
}

D

provider "aws" {
  region = "us-east-1"
  alias  = "us-east"
}

provider "aws" {
  region = "eu-west-1"
  alias  = "eu-west"
}

💡 Hint

Only one provider block can be default (no alias). Others must have aliases.

Terraform allows one default provider without alias. Additional providers must have aliases. Option A correctly sets one default and one aliased provider.

❓ service_behavior

advanced

Effect of missing provider alias in resource

Given two AWS providers configured with aliases, what happens if a resource specifies a provider without alias but multiple providers exist?

Terraform

provider "aws" {
  region = "us-east-1"
  alias  = "east"
}

provider "aws" {
  region = "us-west-2"
  alias  = "west"
}

resource "aws_instance" "example" {
  ami           = "ami-123456"
  instance_type = "t2.micro"
  provider      = aws
}

A Terraform randomly picks one of the aliased providers.

B Terraform uses the provider with alias 'east' by default.

C Terraform uses the provider with alias 'west' by default.

D Terraform raises an error because no default provider is configured.

💡 Hint

Terraform requires a default provider if no alias is specified in resource.

When all providers have aliases, there is no default provider. Specifying provider = aws without alias causes Terraform to error.

❓ security

advanced

Security implications of multiple provider credentials

You configure multiple providers with different credentials for different AWS accounts. What is a key security best practice?

A Share credentials between providers to reduce complexity.

B Store all credentials in the same Terraform configuration file in plain text.

C Use environment variables or secret management tools to inject credentials securely.

D Hardcode credentials in resource blocks for clarity.

💡 Hint

Think about how to keep credentials safe and avoid exposure.

Best practice is to avoid hardcoding credentials and use environment variables or secret managers to keep them secure.

🧠 Conceptual

expert

Understanding provider inheritance in modules

You have a root module with two AWS providers configured: one default and one with alias europe. You call a child module that creates an S3 bucket. The child module does not specify a provider. Which provider will the child module use?

Terraform

provider "aws" {
  region = "us-east-1"
}

provider "aws" {
  region = "eu-west-1"
  alias  = "europe"
}

module "storage" {
  source = "./modules/s3"
}

A The child module uses the default provider (us-east-1).

B The child module uses the aliased provider (europe).

C Terraform raises an error because the child module does not specify a provider.

D The child module randomly picks one of the providers.

💡 Hint

Modules inherit the default provider unless explicitly passed an alias.

Child modules use the default provider from the root module if no provider is specified or passed explicitly.