Using Multiple Providers in Your Configuration

In this lesson you’ll learn how to use the provider meta-argument in Terraform to assign resources to specific provider configurations. This lets a single Terraform configuration target different accounts, regions, or roles (for example, separate AWS accounts or regions for dev and prod) without duplicating whole configurations. Why this matters

Manage multi-region or multi-account deployments from one codebase.
Keep resource definitions centralized while controlling where they are created.
Use distinct credentials, assume-role settings, or endpoints per provider configuration.

How it works

Define one or more provider blocks for the same provider type. Any non-default provider block must include an alias.
Inside a resource block, set the provider meta-argument to tell Terraform which provider configuration to use for that resource.

Example: multi-region AWS providers and S3 buckets

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

provider "aws" {
  alias  = "prod"
  region = "us-west-1"
}

resource "aws_s3_bucket" "dev_bucket" {
  bucket = "my-dev-bucket"
}

resource "aws_s3_bucket" "prod_bucket" {
  provider = aws.prod
  bucket   = "my-prod-bucket"
}

Explanation of the example

The first provider "aws" block (no alias) is the default provider. Any AWS resource that does not specify the provider meta-argument uses this configuration. In the example, dev_bucket is created in us-east-1.
The second provider "aws" block sets alias = "prod" and uses us-west-1. To use that provider, set provider = aws.prod inside the resource block. Here, prod_bucket is created in us-west-1.
Each provider block may include its own credentials, profile, assume_role configuration, or provider-specific settings. This allows targeting different accounts, regions, or roles from the same Terraform code.

When to use this pattern

Use case	Why use multiple provider blocks	Example
Multi-region deployments	Create resources in different regions (primary and DR) without separate configs	`provider "aws" { region = "us-east-1" }` and `provider "aws" { alias="dr" region="us-west-2" }`
Multi-account deployments	Apply resources across accounts by using different credentials or assume-role settings	`provider "aws" { alias="prod" profile="prod-profile" }`
Cross-account or cross-region features	Implement features like S3 replication or cross-account IAM roles where source and destination are in different accounts/regions	Use `provider` on each resource to point to the appropriate account/region

Default provider behavior

A provider block without an alias is the default. Any resource without a provider meta-argument uses that configuration.
Use alias and the provider meta-argument only when a resource must be created with a provider different from the default.

Remember to configure credentials or role-assumption settings appropriately for each provider block. Each aliased provider can (and usually should) have its own authentication configuration (for example, different access keys, profiles, or assume_role settings) so Terraform can authenticate to the correct account or region.

Using aliased providers with modules

When calling a module that needs to target a non-default provider, pass a providers map to the module:

module "example" {
  source = "./modules/example"

  providers = {
    aws = aws.prod
  }
}

Inside the module, resources referencing aws will then use the aliased provider passed from the root module. This pattern keeps module code generic while allowing the root module to control provider targets.

Security and best practices

Avoid hard-coding credentials in provider blocks. Prefer profiles, environment variables, or assume_role where possible.
Keep secrets out of version control. Use your cloud provider’s recommended secret storage or a secrets manager.
Validate that each provider alias has access only to the necessary accounts and permissions.

Quick demo summary

Define multiple provider blocks (one default, additional ones with alias).
Use provider = provider_name.alias inside resource blocks to select the specific provider configuration.
Pass providers into modules via the providers map to control provider usage in nested modules.

Links and references

Course Introduction

Preparing Your Environment

Terraform Foundations

The Core Terraform Workflow

Terraform CLI

Terraform File Structure and Organization

Terraform Configuration - Fundamentals

Understading and Managing Terraform State

Marking Code Reusable

Refactoring Terraform State

Terraform Modules

Managing Resource Behavior and Dependencies

Securing Terraform Configurations

Terraform Troubleshooting

HCP Terraform

Using Multiple Providers in Your Configuration

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