Push To Registry

Push to HCP Packer Registry

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

Reference: HCP Packer Registry

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

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

sshusername = "ubuntu" aminame = "${var.image_name}-${local.timestamp}" }

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

hcppackerregistry { bucketname = var.imagename 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!

bucket_name = "web-server"  # Keep this constant

bucket_labels (optional)

Metadata at bucket level. Updates with each build.

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

build_labels (optional)

Metadata for each iteration. Immutable after build completes.

build_labels = {
  "build-time" = local.timestamp
  "git-commit" = var.git_commit
}

CI/CD Integration

GitHub Actions

name: Build and Push to HCP Packer

on:
  push:
    branches: [main]

env:
  HCP_CLIENT_ID: ${{ secrets.HCP_CLIENT_ID }}
  HCP_CLIENT_SECRET: ${{ secrets.HCP_CLIENT_SECRET }}
  HCP_ORGANIZATION_ID: ${{ secrets.HCP_ORGANIZATION_ID }}
  HCP_PROJECT_ID: ${{ secrets.HCP_PROJECT_ID }}

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: hashicorp/setup-packer@main

      - name: Build and push
        run: |
          packer init .
          packer build \
            -var "git_commit=${{ github.sha }}" \
            .

Querying in Terraform

data "hcp_packer_artifact" "ubuntu" {
  bucket_name  = "web-server"
  channel_name = "production"
  platform     = "aws"
  region       = "us-west-2"
}

resource "aws_instance" "web" {
  ami           = data.hcp_packer_artifact.ubuntu.external_identifier
  instance_type = "t3.micro"

  tags = {
    PackerBucket = data.hcp_packer_artifact.ubuntu.bucket_name
  }
}

Common Issues

Authentication Failed

• Verify HCPCLIENTID and HCPCLIENTSECRET
• Ensure service principal has Contributor role
• Check organization and project IDs

Bucket Name Mismatch

• Keep bucket_name consistent across builds
• Don't include timestamps in bucket_name
• Creates new bucket if name changes

Build Fails

• Packer fails immediately if can't push metadata
• Prevents drift between artifacts and registry
• Check network connectivity to HCP API

Best Practices

• Consistent bucket names - Never change for same image type
• Meaningful labels - Use for versions, teams, compliance
• CI/CD automation - Automate builds and registry pushes
• Immutable build labels - Put changing data (git SHA, date) in build_labels

References

• HCP Packer Documentation
• hcppackerregistry Block
• HCP Terraform Provider

Source & license

This open-source skill is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: hashicorp
• Source: hashicorp/agent-skills
• License: MPL-2.0

Install and usage instructions live in the source repository linked above.