PE software architecture

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 hat 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 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-----.

Facter

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.

The console

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

The console can:

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

RBAC

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.

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.

PuppetDB

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.