How to fix Operation failed: Killed in Terraform

# On Linux, check dmesg for OOM killer events
sudo dmesg | grep -i 'out of memory\|killed process' | tail -20

# Check system memory usage during operation
free -h  # View total/available memory
vmstat 1 10  # Monitor memory in real-time

# Apply with reduced parallelism (use 2-3 for constrained environments)
terraform plan -parallelism=3
terraform apply -parallelism=3

# Set globally in .terraformrc for persistent effect
echo 'apply {
  parallelism = 3
}' >> ~/.terraformrc

jobs:
  terraform:
    runs-on: ubuntu-latest  # Consider ubuntu-latest for more resources
    # GitHub Actions provides ~7GB RAM for ubuntu-latest

# Allocate more memory to container
docker run --memory=4g my-terraform-image

# Monitor and ensure sufficient free memory
free -h
df -h  # Check disk space too

terraform/
  ├── networking/     # VPCs, subnets, security groups
  │   └── main.tf
  ├── compute/        # EC2, containers, compute resources
  │   └── main.tf
  ├── databases/      # RDS, DynamoDB, storage
  │   └── main.tf
  └── monitoring/     # CloudWatch, logs, alerts
      └── main.tf

cd terraform/networking && terraform apply
cd ../compute && terraform apply
cd ../databases && terraform apply

# Apply only compute resources
terraform apply -target='module.compute' -parallelism=2

# Apply specific resources
terraform apply -target='aws_instance.web' -target='aws_instance.app'

# Combine with state file backup
terraform state pull > backup.tfstate
terraform apply -target='module.database' -parallelism=2

# Check current version
terraform version

# Upgrade Terraform (macOS with Homebrew)
brew upgrade terraform

# Upgrade Terraform (manually)
# Download from https://www.terraform.io/downloads

# Upgrade providers in your configuration
required_providers {
  aws = {
    source  = "hashicorp/aws"
    version = "~> 5.0"  # Latest major version
  }
}

# Run init to update providers
terraform init -upgrade

jobs:
  terraform:
    timeout-minutes: 60  # Default is 360 (6 hours)
    runs-on: ubuntu-latest

terraform_apply:
  timeout: 2h  # Default is 1h
  script:
    - terraform apply -auto-approve

timeout(time: 2, unit: 'HOURS') {
  sh 'terraform apply -auto-approve'
}

export TFE_PARALLELISM=3
terraform plan