Learn PACKER with Real Code Examples
Updated Nov 27, 2025
Architecture
Packer CLI -> Template -> Builder -> Provisioner -> Post-Processor -> Output artifact
Template describes the complete build workflow
Builders create base images
Provisioners configure images
Post-processors finalize artifacts for deployment
Rendering Model
Template + variables -> Provisioners -> Builders -> Post-processors -> Artifact
CLI executes the workflow
Artifacts stored in local or cloud repositories
Templates version-controlled for reproducibility
Post-processors optionally upload, compress, or tag artifacts
Architectural Patterns
Client-only CLI
Template-driven workflow
Provisioner/Builder separation
Artifact output storage
CI/CD integration
Real World Architectures
AWS AMI pipelines for enterprise applications
Docker container base image automation
Hybrid cloud image deployments
Immutable server templates for CI/CD
Edge computing image provisioning
Design Principles
Immutable infrastructure
Template-driven builds
Multi-platform support
Integrates with configuration management
Automated CI/CD-friendly workflows
Scalability Guide
Use variables to support multiple environments
Parallelize builds for multi-platform images
Cache base images to reduce build time
Integrate builds into CI/CD pipelines
Maintain reusable provisioner scripts
Migration Guide
Migrate JSON templates to HCL
Update deprecated provisioner syntax
Refactor builder blocks for multi-platform builds
Replace legacy post-processors
Audit artifact outputs for consistency