Puppet is an infrastructure automation tool used by DevOps teams to manage configurations and deployments at scale through code. This comprehensive guide will provide an overview of Puppet, its architecture, how it enables infrastructure-as-code, and best practices for leverage in a DevOps context.
What is Puppet? An Overview
Puppet is a configuration management platform that allows DevOps teams to automate various processes like:
- Provisioning infrastructure (servers, VMs, cloud resources)
- Configuring operating systems and middleware
- Deploying and updating applications
- Ensuring consistency across environments
It follows an agent-master architecture and uses a domain specific language based on Ruby to model the desired state of systems. Infrastructure elements like servers are treated as code that can be versioned, tested and deployed automatically.
Some key stats that highlight Puppet‘s popularity:
- Over 40% of the Fortune 100 use Puppet with 2.5 million nodes under management
- Typical ops team saves 200+ hours per month leveraging Puppet automation
- 3000+ modules provided in Puppet Forge for ready automation
Puppet enables scaled management by removing manual work needed for tasks like configuring operating systems. This frees up developer time to focus on application delivery. Next we‘ll understand how the Puppet architecture achieves this.
Puppet Architecture 101
The Puppet architecture follows a decentralized model with these core components:
Puppet Master
This acts as the central server which has all the configuration logic and oversees the agent nodes. Key responsibilities:
- Has modules, manifests, file templates and other artifacts
- Compiles catalogs with node specific configurations
- Signs certificate requests to establish secure connections
- Orchestrates configuration updates across nodes
Puppet Agent
Agent software runs on each infrastructure node to apply configurations:
- Sends facts/metadata to allow catalog compilation
- Queries master and applies assigned catalog
- Reports back on the catalog application status
Manifests & Modules
- Manifests use Puppet‘s DSL to declare resource attributes
- Modules package manifests, files etc to enable reuse
Certificate Authority
An integrated CA provides SSL certificates to secure traffic between agents and master.
Now let‘s see how this architecture actually rolls out changes…
How Puppet Works
The workflow between Puppet master and agents follows a "pull" model:
- Agents request configurations from the master at periodic intervals
- Agents send facts and current state to the master
- Master compiles a catalog with desired state for that agent
- Agents applies the catalog by making required changes
- Agents reports back change status to the master
This frequent sync allows incremental updates while giving visibility into drifts or failures. If any discrepancies occur, ops teams can investigate and remediate proactively.
Why Puppet for DevOps? Key Benefits
Puppet augments DevOps capabilities around automation, productivity and risk reduction. Main benefits include:
Infrastructure as Code
Model configurations using code constructs like:
- Modules encapsulate related resources
- Manifests declare resources in a declarative model
- Templates can embed custom data
This allows reaping benefits of code management:
- Version control for change tracking
- Testing frameworks to validate functionality
- Peer reviews for quality and collaboration
- Automated deployment of changes
For example, a common pipeline automates testing modules in staging and production by linking Puppet code updates to CI/CD tools like Jenkins.
Resilience Through Consistency
Puppet monitors drift between desired and actual state across thousands of nodes to flag consistency issues. Some examples:
- Auto-remediate security policy deviations
- Fix broken application deployments
- Refresh nodes that have configuration drift
This self-healing capability reduces critical outages significantly. One customer noted a ~65% drop in P1 incidents after Puppet adoption.
Productivity and Collaboration
Developers can self-serve environments needed for faster testing without waiting for manual work by ops teams. Common examples include:
- Spin up testing stacks on-demand with pre-baked configurations
- Deploy build artifacts seamlessly through staging environments
- Eliminate wait times getting production-parity infrastructure
This helps developers focus on application code rather than waste cycles on procurement. Ops members can specialize on enhancing automation capabilities. Collaboration improves through a unified platform.
Next, we‘ll cover some best practices to leverage Puppet effectively.
Best Practices for Puppet in DevOps
To maximize business impact, keep these guidelines in mind:
Start Small, Fail Fast, Learn Fast
Beginning an automation journey can be daunting. It‘s best to start small, learn quickly and expand:
- Automate just the new server onboarding process first
- Add modules to handle additional software deployments next
- Monitor for failure cases and refine modules quickly
- Leverage community modules to ramp up faster
This focuses innovation efforts on the most impactful areas first.
Infrastructure Testing as Code
Apply software best practices like unit testing to Puppet code:
- Create environments for sand-boxed testing safely
- Build automated test cases on infrastructure requirements
- Fix issues faster through test-driven development
- Achieve staging environments closer to production
Testing allows predictable infrastructure changes with confidence.
Monitoring as an Early Warning System
Monitor infrastructure managed by Puppet actively:
- Track agent check-ins for communication failures
- Get notified if resources drift from desired state
- Analyze event logs to improve manifests over time
- Enforce security policy adherence
This allows proactively identifying risks before they cause outages.
Scale Horizontally as Needed
For larger deployments, scale Puppet infrastructure:
- Add compile masters to share agent load geographically
- Split workloads by business units or technology tiers
- Automate front-ends for self-servicing resources
A layered infrastructure improves resilience and performance.
Conclusion
Puppet helps transform infrastructure management challenges through automation using proven software techniques. By codifying desired state, continuous deployment and self-healing of modern infrastructure stacks is achievable. Active monitoring, testing and quick iteration on issues drives consistency at scale. Mature capabilities around deployment, testing and visibility help accelerate application delivery pipelines in DevOps programs. With growing community support, Puppet has cemented itself as a mission-critical platform for driving infrastructure agility.
