puppet-repl

Table of Contents generated with DocToc

• puppet-repl
  • Compatibility
  • Production usage
  • Installation
  • Load path
  • Interactive demo
  • Web demo
  • Usage
  • Using Variables
    • Listing variables
  • Listing functions
  • Using functions
  • Duplicate resource error
  • Setting the puppet log level
  • Remote nodes
    • Setup
    • Usage
      • Command line:
      • From repl session:
  • Auto Complete
  • Playback support
  • Troubleshooting
  • Copyright

puppet-repl

A interactive command line tool for evaluating and debugging the puppet language.

Compatibility

Requires Puppet 3.8+ and only uses the future parser.

Production usage

The puppet repl is a developer tool that should only be used when writing puppet code. Although it might seem useful to install on your production puppet master. Please do not install because of the puppet-repl gem dependencies that might conflict with your existing environment.

Installation

gem install puppet-repl

Load path

puppet-repl will load all functions from your basemodulepath and environmentpath.

This means if you run puppet module install puppetlabs-stdlib and they will be available in the repl.

Interactive demo

I have put together a repo with a few setup instructions that will assist you in setting up a "mock" environment for usage with the puppet-repl. This was originally intended when giving a demo of the repl, but also seems useful for other people.

https://github.com/nwops/puppet-repl-demo

Web demo

There is a web version of the puppet-repl online but is somewhat limited at this time. In the future we will be adding lots of awesome features to the web repl.

Usage

Puppet-repl will only parse and evaulate your code. It will not build a catalog and try to enforce the catalog. This has a few side affects.

1. Type and provider code will not get run.
2. Nothing is created or destroyed on your system.

prepl

Example Usage

MacBook-Pro-2/tmp % prepl
Ruby Version: 2.0.0
Puppet Version: 3.8.5
Puppet Repl Version: 0.0.7
Created by: NWOps <[e-mail]>
Type "exit", "functions", "vars", "krt", "facts", "reset", "help" for more information.

>> ['/tmp/test3', '/tmp/test4'].each |String $path| { file{$path: ensure => present} }
  => [
     [0] "/tmp/test3",
     [1] "/tmp/test4"
 ]
 >>

Using Variables

MacBook-Pro-2/tmp % prepl
Ruby Version: 2.0.0
Puppet Version: 3.8.5
Puppet Repl Version: 0.0.7
Created by: NWOps <[e-mail]>
Type "exit", "functions", "vars", "krt", "facts", "reset", "help" for more information.

>>

>> $config_file = '/etc/httpd/httpd.conf'
 => "/etc/httpd/httpd.conf"
 >> file{$config_file: ensure => present, content => 'hello'}
  => Puppet::Type::File {
                        path => "/etc/httpd/httpd.conf",
                    provider => posix,
                      ensure => present,
                     content => "{md5}5d41402abc4b2a76b9719d911017c592",
                    checksum => nil,
                      backup => "puppet",
                     replace => true,
                       links => manage,
                       purge => false,
                sourceselect => first,
                   show_diff => true,
        validate_replacement => "%",
          source_permissions => use,
     selinux_ignore_defaults => false,
                    loglevel => notice,
                        name => "/etc/httpd/httpd.conf",
                       title => "/etc/httpd/httpd.conf"
 }
 >>

Listing variables

To see the current variables in the scope use the vars keyword.

Listing functions

Knowing what functions are available and where they come from is extremely helpful especially in a repl session. Run the functions keyword to get a name spaced list of functions. You can further filter out functions by passing in a filter argument. functions stdlib

Using functions

Functions will run and produce the desired output. If you type the word functions a list of available functions will be displayed on the screen along with a namespace to help you identify where they came from.

>> split('hello/there/one/two/three','/')
 => ["hello", "there", "one", "two", "three"]

So you can imagine how much fun this can be trying out different types of functions.

Duplicate resource error

Just like normal puppet code you cannot create duplicate resources.

>> file{'/tmp/failure2.txt': ensure => present}
 => Evaluation Error: Error while evaluating a Resource Statement, Duplicate declaration: File[/tmp/failure2.txt] is already declared in file :1; cannot redeclare at line 1 at line 1:1

You can reset the parser by running reset within the repl without having to exit.

Setting the puppet log level

If you want to see what puppet is doing behind the scenes you can set the log level via :set loglevel debug. Valid log levels are debug, info, warning and other levels defined in puppet config reference .

Remote nodes

This is new for 0.2.0. The puppet-repl now has the ability to pull in remote node information. Instead of mocking facts you can pull in real information! Get real facts and real node classification from the puppet master and then play with the info in the repl session. This is made possible by using the puppet node indirector interface.

ie. puppet node find hostname --terminus rest --render-as yaml

In order to use this feature you will need to setup a few things.

Setup

1. Allow node rest calls to your workstation on the puppet master(s) See https://github.com/nwops/puppet-repl/issues/17 for more info on allowing this rule.

2. Ensure you have the same code that your puppet master does. Since this pulls in classification you will need to have all the puppet modules defined in your environmentpath or basemodulepath. The simple thing to do is to point your basemodulepath to your fixtures directory if using rspec-puppet or some other high level modules directory. For PE users you will want to ensure you have all the pe specific modules in your development environment. Not doing this step will result in class not found errors.

3. Set the server config in your local puppet.conf. (on your development machine)

   a. Find your puppet config file puppet config print config

   b. edit the config file with an editor

   c. add server = <hostname> to your main block

4. If using hiera you also need to set the path to your hiera config file since the puppet-repl will be compiling puppet code which could in turn call hiera functions. Additionally, make sure your hiera config points to the correct data location.

[main]
  server = pe-puppet.localdomain
  basemodulepath = /Users/cosman/github/puppet-repl-demo/modules:/Users/cosman/Downloads/pe_modules
  hiera_config = /Users/cosman/github/puppet-repl-demo/hieradata/hiera.yaml

Usage

There are two ways of using the remote node feature. You can either pass in the node name from the command line or set the node name from the repl session.

Command line:

prepl -n node_name

From repl session:

:set node node_name

This is also extremely useful to check classification rules and variables by your ENC. So instead of running your ENC script manually we get the puppet master to run this indirectly and return the results to you.

Auto Complete

The puppet-repl uses readline internally. So any variable or function is also available for auto completion. Press the tab key to engage the auto complete functionality.

Currently native functions are not available in auto complete. See #24

FacterDB and using different fact sets

The puppet-repl internally leverages the facterdb gem to load pre-cached facts into the repl session. At some point you may need to override the repl's default fact set with something of your own choosing. You can do this by setting one of the environment variables below.

• REPL_FACTERDB_FILTER Sets the entire filter
• REPL_FACTER_OS_VERSION Sets the OS version (only works with RHEL clones and Fedora)
• REPL_FACTER_OS_NAME Sets the OS name (only works with RHEL clones and Fedora)
• REPL_FACTER_VERSION Sets the facter version to use in the repl session (uses facter 3.1 for puppet 4.4+ and facter 2.4 for 3.8-4.4)

By default it looks something like operatingsystem=Fedora and operatingsystemrelease=23 and architecture=x86_64 and facterversion=/^3\\.1/ depending on the puppet version currently running.

You can display the current facterdb filter by running facterdb_filter from the repl session.

Why do facter versions matter? While facter and puppet work independently just fine, newer forge modules utilize certain data structures found only in newer versions of facter. So its really up to the puppet code you use. With facter 3, almost every fact is now a data structure. So if you are having issues with facts not existing in the repl you may need to change the facter version REPL_FACTER_VERSION to something different.

Playback support

Puppet-repl now supports playing back files or urls and loading the content into the repl session. This means if you want to start a repl session from an existing file or url you can play the content back in the repl. You can also playback a file that contains puppet code and repl commands.

play https://gist.githubusercontent.com/logicminds/f9b1ac65a3a440d562b0/raw

or

prepl -p https://gist.githubusercontent.com/logicminds/f9b1ac65a3a440d562b0/raw

or just use STDIN prepl <some_file> or echo "abs(-3)" | prepl

Web based playback support

If using the web based repl you can playback a shared url which would start a repl session and then load the content from the url or parameter.

Example: https://puppet-repl.com/play?url=https://gist.github.com/logicminds/64f0fe9f64339f18f097a9f42acd6276

or for single commands

https://www.puppet-repl.com/play?content=vars

Please note the web based repl only contains a minimal amount of puppet modules. So its likely that your code may not work if using third party modules. This may change in the future though.

Troubleshooting

Please file an issue so we can track bugs.

Pull requests welcomed.

Copyright

Copyright (c) 2016 Corey Osman. See LICENSE.txt for further details.