user data argument in aws instance

user_data (optional) user data argument in aws_instance resource to provide when launching the instance, such as shell scripts.

  user_data                   = templatefile("${path.module}/assets/your_instance_data.tftpl", {})

• Do not include passwords or sensitive information (tf.io)

 user_data = templatefile("${path.module}/path/yourfile.tftpl", {
   ecs_cluster            = aws_ecs_cluster.your_cluster.name
   ecs_instance_attribute = var.ecs_instance_attribute
 })

Important notes:

• Updates to this field will trigger a stop/start of the EC2 instance by default.
• Do not pass gzip-compressed data via this argument; see user_data_base64 instead.
• If the user_data_replace_on_change is set then updates to this field will trigger a destroy and recreate

• https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/instance#user_data

lifecycle {
  ignore_changes = [user_data]
 }

Claude exmaple

resource "aws_instance" "your_test_machine" {
  # ...
  user_data = <<-EOF
    #!/bin/bash
    echo "ubuntu:tupassword" | chpasswd
    passwd -u ubuntu
  EOF
}

Related

• templatefile, *.tftpl
• http://169.254.169.254/latest/user-data
• https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/instancedata-add-user-data.html
• /var/lib/cloud/instance/user-data.txt
• root_block_device
• user_data_replace_on_change
• Cloud-init: /var/log/cloud-init.log, /var/log/cloud-init-output.log
• aws_volume_attachment
• Terraform lifecycle meta-argument
• aws ec2 enable-serial-console-access

See also

• user_data, .tftpl, templatefile
• Terraform AWS: aws_instance: ami, availability_zone, instance_type, key_name, aws_key_pair, monitoring, associate_public_ip_address, tenancy, subnet_id, user_data, iam_instance_profile, vpc_security_group_ids, root_block_device, ebs_block_device, volume_size, disable_api_termination, disable_api_stop