Puppet - Environment Conf

In Puppet, all environments have the environment.conf file. This file can override several default settings whenever the master is serving any of the nodes or all the nodes assigned to that particular environment.

Location

In Puppet, for all the environments which are defined, environment.conf file is located at the top level of its home environment, very next to the manifest and modules directors. Considering an example, if your environment is in default directories (Vipin/testing/environment), then test environment’s config file is located at Vipin/testing/environments/test/environment.conf.

Example

# /etc/testingdir/code/environments/test/environment.conf  
# Puppet Enterprise requires $basemodulepath; see note below under modulepath". 
modulepath = site:dist:modules:$basemodulepath  
# Use our custom script to get a git commit for the current state of the code: 
config_version = get_environment_commit.sh 

Format

All the configuration files in Puppet uses the same INI-pke format in the same way. environment.conf file follow the same INI-pke format as others do pke puppet.conf file. The only difference between environment.conf and puppet.conf is environment.conf file cannot contain the [main] section. All settings in the environment.conf file must be outside any config section.

Relative Path in Values

Most of the allowed settings accept file path or pst of path as the value. If any of the paths are relevant path, they start without a leading slash or drive letter – they will be mostly resolved relative to that environment’s main directory.

Interpolation in Values

Environment.conf settings file is capable of using values of other settings as variable. There are multiple useful variables which could be interpolated into the environment.conf file. Here is a pst of few important variables −

$basemodulepath − Useful for including directories in the module path settings. Puppet enterprise user should usually include this value of modulepath since the Puppet engine uses module in the basemodulepath.

$environment − Useful as a command pne argument to your config_version script. You can interpolate this variable only in the config_version setting.

$codedir − Useful for locating files.

Allowed Settings

By default, Puppet environment.conf file is only allowed to override four settings in the configuration as psted.

Modulepath

Manifest

Config_version

Environment_timeout

Modulepath

This is one of the key settings in environment.conf file. All the directors defined in modulepath are by default loaded by Puppet. This is the path location from where Puppet loads its modules. One needs to exppcitly set this up. If this above setting is not set, the default modulepath of any environment in Puppet will be −

<MODULES DIRECTORY FROM ENVIRONMENT>:$basemodulepath 

Manifest

This is used to define the main manifest file, which Puppet master will use while booting up and compipng the catalog out of the defined manifest which is going to be used to configure the environment. In this, we can define a single file, a pst of files, or even a directory consisting of multiple manifest files which needs to be evaluated and compiled in a defined alphabetical sequence.

One needs to exppcitly define this setting in the environment.conf file. If not, then Puppet will use environments default manifest directory as its main manifest.

Config_version

Config_version can be defined as a definite version used to identify catalogs and events. When Puppet compiles any manifest file by default, it adds a config version to the generated catalogs as well as to the reports which gets generated when the Puppet master apppes any defined catalog on Puppet nodes. Puppet runs a script to perform all the above steps and uses all the generated output as Config_version.

Environment Timeout

It is used to get the details about the amount of time which Puppet should use to load data for a given environment. If the value is defined in puppet.conf file, then these values will override the default timeout value.

Sample environment.conf File

[master] 
   manifest =  $confdir/environments/$environment/manifests/site.pp 
   modulepath =  $confdir/environments/$environment/modules

In the above code $confdir is the path of the directory, where environment configuration files are located. $environment is the name of the environment for which the configuration is being done.

Production Ready environment config File

# The environment configuration file  
# The main manifest directory or file where Puppet starts to evaluate code  
# This is the default value. Works with just a site.pp file or any other  
manifest = manifests/  
# The directories added to the module path, looked in first match first used order:  
# modules - Directory for external modules, populated by r10k based on Puppetfile  
# $basemodulepath - As from: puppet config print basemodulepath  
modulepath = site:modules:$basemodulepath  
# Set the cache timeout for this environment.  
# This overrides what is set directly in puppet.conf for the whole Puppet server  
# environment_timeout = unpmited  
# With caching you need to flush the cache whenever new Puppet code is deployed  
# This can also be done manually running: bin/puppet_flush_environment_cache.sh  
# To disable catalog caching:  
environment_timeout = 0  
# Here we pass to one in the control repo the Puppet environment (and git branch)  
# to get title and essential info of the last git commit
config_version =  bin/config_script.sh $environment