PE software architecture

Puppet Enterprise (PE) is made up of various components and services including the primary server and compilers, the Puppet agent, console services, Code Manager and r10k, orchestration services, and databases.

The following diagram shows the architecture of a typical PE installation.

A typical PE installation showing a primary server, compilers, console services, and managed nodes.

The primary server and compilers

The primary server is the central hub of activity and process in Puppet Enterprise. This is where code is compiled to create agent catalogs, and where SSL certificates are verified and signed.

PE infrastructure components are installed on a single node: the primary server. The primary server always contains a compiler and a Puppet Server. As your installation grows, you can add additional compilers to distribute the catalog compilation workload.

Each compiler contains the Puppet Server, the catalog compiler, and an instance of file sync.

Puppet Server

Puppet Server is an application that runs on the Java Virtual Machine (JVM) on the primary server. In addition to hosting endpoints for the certificate authority service, it also powers the catalog compiler, which compiles configuration catalogs for agent nodes, using Puppet code and various other data sources.

Catalog compiler

To configure a managed node, the agent uses a document called a catalog, which it downloads from the primary server or a compiler. The catalog describes the desired state for each resource on the node that you want to manage, and it can specify dependency information for resources that need to be managed in a certain order.

File sync

File sync keeps your code synchronized across multiple compilers. When triggered by a web endpoint, file sync takes changes from the working directory on the primary server and deploys the code to a live code directory. File sync then deploys that code to any compilers so that your code is deployed only when it's ready.

Certificate Authority

The internal certificate authority (CA) service:
  • Accepts certificate signing requests (CSRs) from nodes
  • Serves certificates and a certificate revocation list (CRL) to nodes
  • Accepts commands to sign or revoke certificates (optional)

The CA service uses CSPRNG-generated .pem files in the standard ssldir to store credentials. You can use the puppetserver ca command to interact with these credentials, including listing, signing, and revoking certificates.

Depending on your architecture and security needs, you can host the CA server on either the primary server or its own node. The CA service on compilers is configured, by default, to proxy CA requests to the CA server.

By default, the CA private key is located on the CA server at cadir/ca_key.pem. The default cadir is /etc/puppetlabs/puppetserver/ca. If you choose to use another directory, the key file must be stored in location readable by the pe-puppet user.

If you generate your own CA private key, the key must be RSA and the key file's PEM contents must begin with either BEGIN RSA PRIVATE KEY or BEGIN PRIVATE KEY. The entire CA chain must use the SHA-2 (or stronger) signing algorithm. Additionally, because the CA private key is one of the most critical files for security in your Puppet certificate infrastructure, the pe-puppet user must be the file owner and the permissions must be set to either mode: 0640 or -rw-r-----.

The Puppet agent

Managed nodes run the Puppet agent application, usually as a background service. The primary server and any compilers also run a Puppet agent.

Periodically, the agent sends facts to a primary server and requests a catalog. The primary server compiles the catalog using several sources of information, and returns the catalog to the agent.

After it receives a catalog, the agent applies it by checking each resource the catalog describes. If it finds any resources that are not in their desired state, it makes the changes necessary to correct them. (Or, in no-op mode, it reports on what changes would have been made.)

After applying the catalog, the agent submits a report to its primary server. Reports from all the agents are stored in PuppetDB and can be accessed in the console.

Puppet agent runs on *nix and Windows systems.


Facter is the cross-platform system profiling library in Puppet. It discovers and reports per-node facts, which are available in your Puppet manifests as variables.

Before requesting a catalog, the agent uses Facter to collect system information about the machine it’s running on.

For example, the fact os returns information about the host operating system, and networking returns the networking information for the system. Each fact has various elements to further refine the information being gathered. In the networking fact, networking.hostname provides the hostname of the system.

Facter ships with a built-in list of core facts, but you can build your own custom facts if necessary.

You can also use facts to determine the operational state of your nodes and even to group and classify them in the NC.

Console services

The console services includes the console, role-based access control (RBAC) and activity services, and the node classifier.

The console

The console is the web-based user interface for managing your systems.

The console can:

  • browse and compare resources on your nodes in real time.
  • analyze events and reports to help you visualize your infrastructure over time.
  • browse inventory data and backed-up file contents from your nodes.
  • group and classify nodes, and control the Puppet classes they receive in their catalogs.
  • manage user access, including integration with external user directories.

The console leverages data created and collected by PE to provide insight into your infrastructure.


In PE, you can use RBAC to manage user permissions. Permissions define what actions users can perform on designated objects.

For example:

  • Can the user grant password reset tokens to other users who have forgotten their passwords?
  • Can the user edit a local user's role or permissions?
  • Can the user edit class parameters in a node group?

The RBAC service can connect to external LDAP directories. This means that you can create and manage users locally in PE, import users and groups from an existing directory, or do a combination of both. PE supports OpenLDAP and Active Directory.

You can interact with the RBAC and activity services through the console. Alternatively, you can use the RBAC service API and the activity service API. The activity service logs events for user roles, users, and user groups.

PE users generate tokens to authenticate their access to certain command line tools and API endpoints. Authentication tokens are used to manage access to the following PE services and tools: Puppet orchestrator, Code Manager , Node Classifier, role-based access control (RBAC), and the activity service.

Authentication tokens are tied to the permissions granted to the user through RBAC, and provide users with the appropriate access to HTTP requests.

Node classifier

PE comes with its own node classifier (NC), which is built into the console.

Classification is when you configure your managed nodes by assigning classes to them. Classes provide the Puppet code—distributed in modules—that enable you to define the function of a managed node, or apply specific settings and values to it. For example, you might want all of your managed nodes to have time synchronized across them. In this case, you would group the nodes in the NC, apply an NTP class to the group, and set a parameter on that class to point at a specific NTP server.

You can create your own classes, or you can take advantage of the many classes that have already been created by the Puppet community. Reduce the potential for new bugs and to save yourself some time by using existing classes from modules on the Forge, many of which are approved or supported by Puppet by Perforce

You can also classify nodes using the NC API.

Code Manager and r10k

PE includes tools for managing and deploying your Puppet code: Code Manager and r10k.

These tools install modules, create and maintain environments, and deploy code to your primary servers, all based on code you keep in Git. They sync the code to your primary servers, so that all your servers start running the new code at the same time, without interrupting agent runs.

Both Code Manager and r10k are built into PE, so you don't have to install anything, but you need to have a basic familiarity with Git.

Code Manager comes with a command line tool which you can use to trigger code deployments from the command line.

Orchestration services

Orchestration services is the underlying toolset that manages Puppet runs, tasks, and plans, allowing you to make on-demand changes in your infrastructure.

For example, you can use it to enforce change on the environment level without waiting for nodes to check in for regular 30-min intervals, or use it to schedule a task on target nodes once per day.

The orchestration service interacts with PuppetDB to retrieve facts about nodes. To run orchestrator jobs, users must first authenticate to Puppet Access, which verifies their user and permission profile as managed in RBAC.

Agentless Catalog Executor (ACE) service

The ACE service enables you to run Puppet jobs, like tasks and plans, on nodes that don't have a Puppet agent installed on them. ACE service primarily runs through the orchestrator but it can be configured by itself. Go to PE ACE server configuration to learn about configuring ACE.

Bolt vs ACE: Orchestrator uses both ACE and Bolt to run tasks and plans. While both can act on agentless targets, the primary difference is that Bolt server works with agentless nodes over WinRM or SSH, whereas ACE works with agentless devices, like network switches and firewalls, over other transports. Go to PE Bolt server configuration to learn about how Bolt works in PE and configuring the Bolt server.

PE databases

PE uses PostgreSQL as a database backend. You can use an existing instance, or PE can install and manage a new one.

The PE PostgreSQL instance includes the following databases:

Database Description
pe-activity Activity data from the Classifier, including who, what and when
pe-classifier Classification data, all node group information
pe-puppetdb Exported resources, catalogs, facts, and reports (see more, below)
pe-rbac Users, permissions, and AD/LDAP info
pe-orchestrator Details about job runs, users, nodes, and run results


PuppetDB collects data generated throughout your Puppet infrastructure. It enables advanced features like exported resources, and is the database from which the various components and services in PE access data. Agent run reports are stored in PuppetDB.

See the PuppetDB overview for more information.

Security and communications

Puppet Enterprise (PE) services and components use a variety of communication and security protocols.

Service/Component Communication Protocol Authentication Authorization
Puppet Server HTTPS SSL certificate verification with Puppet CA trapperkeeper-auth
Certificate Authority HTTPS SSL certificate verification with Puppet CA trapperkeeper-auth
Puppet agent HTTPS SSL certificate verification with Puppet CA n/a
PuppetDB HTTPS externally, or HTTP on the loopback interface SSL certificate verification with Puppet CA SSL certificate allow list
PostgreSQL PostgreSQL TCP, SSL for PE SSL certificate verification with Puppet CA SSL certificate allow list
Activity service HTTPS SSL certificate verification with Puppet CA, token authentication RBAC user-based authorization
RBAC HTTPS SSL certificate verification with Puppet CA, token authentication RBAC user-based authorization
Classifier HTTPS SSL certificate verification with Puppet CA, token authentication RBAC user-based authorization
Console Services UI HTTPS Session-based authentication RBAC user-based authorization
Orchestrator HTTPS, Secure web sockets RBAC token authentication RBAC user-based authorization
PXP agent Secure web sockets SSL certificate verification with Puppet CA n/a
PCP broker Secure web sockets SSL certificate verification with Puppet CA trapperkeeper-auth
File sync HTTPS SSL certificate verification with Puppet CA trapperkeeper-auth
Code Manager HTTPS; can fetch code remotely via HTTP, HTTPS, and SSH (via Git) RBAC token authentication; for remote module sources, HTTP(S) Basic or SSH keys RBAC user-based authorization; for remote module sources, HTTP(S) Basic or SSH keys

Compatible ciphers

Puppet Enterprise (PE) is compatible with a variety of ciphers for different services.

Most TLSv1.2 ciphers are available in IANA or OpenSSL format, depending on the service it's used for. You can use the same TLSv1.3 ciphers interchangeably for OpenSSL and IANA formats.
Use IANA format for these services on TLSv1.2:
Puppet Server
Console services
Use OpenSSL format for these services on TLSv1.2:
Bolt Server
ACE server

To use TLSv1.3, you must enable both TLSv1.2 and TLSv1.3.

To use ECDSA ciphers, you must use your own CA certificates with ECC keys, rather than Puppet Server-generated certificates.

The following table describes the default TLSv1.2 and TLSv1.3 ciphers PE accepts for FIPS and non-FIPS installations. If you use an unsupported cipher, it is rejected when the service tries to establish a connection.

Ciphers in IANA format Ciphers in OpenSSL format TLS protocol FIPS support
TLS_AES_256_GCM_SHA384 TLS_AES_256_GCM_SHA384 TLSv1.3 Yes
TLS_AES_128_GCM_SHA256 TLS_AES_128_GCM_SHA256 TLSv1.3 Yes