How to fix Error: Resource creation cancelled in Terraform

The 'Resource creation cancelled' message is usually a cascade effect. Look at the full Terraform output to find the original error that triggered the cancellation:

terraform apply 2>&1 | tee apply.log

Search the log for the first error before any cancelled messages. The root cause could be:
- A network timeout
- Invalid resource configuration
- Missing required arguments
- Provider authentication failure

After interruption or cancellation, your state may be out of sync with the cloud:

# Refresh state to see what actually exists
terraform refresh

# Check what Terraform thinks exists
terraform state list

# View the state for a specific resource
terraform state show aws_instance.example

If resources exist in the cloud but not in your state, you'll need to import them.

If a resource was created in the cloud but Terraform's state wasn't updated due to cancellation:

# Find the resource ID in your cloud provider console
# For AWS EC2:
terraform import aws_instance.example i-1234567890abcdef0

# For AWS RDS:
terraform import aws_db_instance.example mydb

# For Azure:
terraform import azurerm_resource_group.example /subscriptions/{subId}/resourceGroups/mygroup

After importing, run terraform plan to confirm no unintended changes.

If cancellation is cascading through dependent resources, review your resource dependencies:

resource "aws_instance" "app_server" {
  # Ensure security group exists first
  vpc_security_group_ids = [aws_security_group.main.id]

  # Or use explicit dependency
  depends_on = [aws_security_group.main]
}

Use terraform graph to visualize dependencies:

terraform graph | dot -Tsvg > graph.svg

Run Terraform with reduced parallelism to create resources sequentially. This makes it easier to see which specific resource fails:

# Create resources one at a time instead of in parallel (default is 10)
terraform apply -parallelism=1

This approach also prevents cascading cancellations—if one resource fails, only that one is affected, not a batch of dependent resources.

Get detailed traces of where and why cancellation occurred:

export TF_LOG=trace
terraform apply 2>&1 | tee terraform-debug.log

# Search for cancellation context
grep -i 'cancel\|deadline\|context' terraform-debug.log

Look for messages like "context cancelled," "context deadline exceeded," or "run context exists, stopping." These indicate the exact point where Terraform initiated the cancellation.

Ensure you have valid credentials and the cloud provider is accessible:

# Test AWS credentials
aws sts get-caller-identity

# Test Azure login
az account show

# Test GCP credentials
gcloud auth list

Also check the cloud provider's status page for any service degradation or outages that might cause cancellations.