How to fix Error: Failed to query available provider packages in Terraform

First, check if you can reach the Terraform Registry:

ping registry.terraform.io
curl -I https://registry.terraform.io

If both commands fail, your network is blocking access to the registry. Check your firewall rules, proxy settings, and ensure you have internet connectivity.

Delete the local Terraform cache and lock file, then reinitialize:

rm -rf .terraform
rm .terraform.lock.hcl
terraform init

This forces Terraform to re-fetch all provider information from the registry.

If you have version constraints that don't match available releases, use the -upgrade flag:

terraform init -upgrade

This tells Terraform to select new provider versions that satisfy your constraints, rather than using locked versions.

Verify your required_providers block in your Terraform files. Ensure version constraints are valid:

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 5.0"
    }
  }
}

Run terraform providers to see what version constraints are active:

terraform providers

If constraints conflict between modules, adjust them so they have overlapping version ranges.

Some providers have multiple source addresses. For example, the DataDog provider is datadog/datadog, not hashicorp/datadog. Check the official Terraform Registry documentation for the correct source:

required_providers {
  datadog = {
    source  = "datadog/datadog"  # Correct
    version = "~> 3.0"
  }
}

If you're using a VPN or proxy, Go's DNS client may have issues. Try switching to a public DNS server:

export GODEBUG=netdns=go
terraform init

Or configure your system to use Google's public DNS (8.8.8.8) instead of your local DNS server.

If you're in a region with restricted access to HashiCorp's repositories, configure a Terraform Registry mirror in your .terraformrc or terraform.rc file:

provider_installation {
  network_mirror {
    url = "https://terraform-mirror.example.com"
  }
  direct {
    exclude = ["hashicorp/*"]
  }
}

Contact your infrastructure team for the correct mirror URL.

Ensure your Terraform version is compatible with the providers you're trying to use:

terraform version

Consult the provider documentation for minimum Terraform version requirements. If your Terraform version is too old, upgrade it:

terraform -install-dir=/usr/local/bin upgrade

Or use a version manager like tfenv to switch versions.