push-to-registry

# Push to HCP Packer Registry

Configure Packer templates to push build metadata to HCP Packer registry.

**Reference:** [HCP Packer Registry](https://developer.hashicorp.com/hcp/docs/packer)

> **Note:** HCP Packer is free for basic use. Builds push metadata only (not actual images), adding minimal overhead (<1 minute).

## Basic Registry Configuration

```hcl
packer {
  required_version = ">= 1.7.7"
}

variable "image_name" {
  type    = string
  default = "web-server"
}

locals {
  timestamp = regex_replace(timestamp(), "[- TZ:]", "")
}

source "amazon-ebs" "ubuntu" {
  region        = "us-west-2"
  instance_type = "t3.micro"

  source_ami_filter {
    filters = {
      name = "ubuntu/images/*ubuntu-jammy-22.04-amd64-server-*"
    }
    most_recent = true
    owners      = ["099720109477"]
  }

  ssh_username = "ubuntu"
  ami_name     = "${var.image_name}-${local.timestamp}"
}

build {
  sources = ["source.amazon-ebs.ubuntu"]

  hcp_packer_registry {
    bucket_name = var.image_name
    description = "Ubuntu 22.04 base image for web servers"

    bucket_labels = {
      "os"   = "ubuntu"
      "team" = "platform"
    }

    build_labels = {
      "build-time" = local.timestamp
    }
  }

  provisioner "shell" {
    inline = [
      "sudo apt-get update",
      "sudo apt-get upgrade -y",
    ]
  }
}
```

## Authentication

Set environment variables before building:

```bash
export HCP_CLIENT_ID="your-service-principal-client-id"
export HCP_CLIENT_SECRET="your-service-principal-secret"
export HCP_ORGANIZATION_ID="your-org-id"
export HCP_PROJECT_ID="your-project-id"

packer build .
```

### Create HCP Service Principal

1. Navigate to HCP → Access Control (IAM)
2. Create Service Principal
3. Grant "Contributor" role on project
4. Generate client secret
5. Save client ID and secret

## Registry Configuration Options

### bucket_name (required)
The image identifier. Must stay consistent across builds!

```hcl
bucket_name = "web-server"  # Keep this constant
```

### b