Add support to store environment variables as facts

README.md

@@ -22,17 +22,7 @@ require 'voxpupuli/acceptance/spec_helper'
 configure_beaker
 ```
 
-It is also possible to do per host configuration
-
-```ruby
-require 'voxpupuli/acceptance/spec_helper_acceptance'
-
-configure_beaker do |host|
-  if fact_on(host, 'os.name') == 'CentOS'
-    install_package(host, 'epel-release')
-  end
-end
-```
+# Running tests
 
 This module provides no rake helpers but leaves that to [puppetlabs_spec_helper](https://github.com/puppetlabs/puppetlabs_spec_helper). Commonly invoked as:
 
@@ -46,9 +36,31 @@ Other common environment variables:
 * `BEAKER_destroy` can be set to `no` to avoid destroying the box after completion. Useful to inspect failures
 * `BEAKER_provision` can be set to `no` to reuse a box. Note that the box must exist already. See `BEAKER_destroy`
 
-# Modules
+Since it's still plain [RSpec](https://rspec.info/), it is also possible to call an individual test file:
+
+```bash
+BEAKER_setfile=centos7-64 bundle exec rspec spec/acceptance/my_test.rb
+```
+
+# Customizing host configuration
+
+## Per host configuration
+
+It is also possible to do per host configuration by providing a block:
+
+```ruby
+require 'voxpupuli/acceptance/spec_helper_acceptance'
+
+configure_beaker do |host|
+  if fact_on(host, 'os.name') == 'CentOS'
+    install_package(host, 'epel-release')
+  end
+end
+```
+
+## Installing Puppet Modules
 
-## Metadata
+### Metadata
 
 By default the module uses [beaker-module_install_helper](https://github.com/puppetlabs/beaker-module_install_helper). Its approach is copying the module and then install every dependency as listed in the module's metadata.json. This is a slow process and if the latest modules aren't accepted, it can lead to problems.
 
@@ -57,7 +69,7 @@ By default the module uses [beaker-module_install_helper](https://github.com/pup
 configure_beaker(modules: :metadata)
 ```
 
-## Fixtures
+### Fixtures
 
 An alternative is to use the fixtures:
 
@@ -72,9 +84,47 @@ This will switch to use [puppet-modulebuilder](https://github.com/puppetlabs/pup
 task :beaker => "spec_prep"
 ```
 
-## None
+### None
 
 It's also possible to skip module installation altogether, giving the module developer complete freedom to handle this.
 ```ruby
 configure_beaker(modules: nil)
 ```
+
+## Environment variables to facts
+
+It can be useful to provide facts via environment variables. A possible use is run the test suite with version 1.0 and 1.1. Often it's much easier to run the entire suite with version 1.0 and run it with 1.1 in a complete standalone fashion.
+
+Voxpupuli-acceptance converts all environment variables starting with `BEAKER_FACTER_` and stores them in `/etc/facter/facts.d/voxpupuli-acceptance-env.json` on the target machine. All environment variables are converted to lowercase.
+
+Given following `spec_helper_acceptance.rb` is used:
+
+```ruby
+require 'voxpupuli/acceptance/spec_helper_acceptance'
+
+MANIFEST = <<PUPPET
+class { 'mymodule':
+  version => fact('mymodule_version'),
+}
+PUPPET
+
+configure_beaker do |host|
+  apply_manifest_on(host, MANIFEST, catch_failures: true)
+end
+```
+
+Then it can be tested with:
+```bash
+BEAKER_FACTER_MYMODULE_VERSION=1.0 bundle exec rake beaker
+BEAKER_FACTER_MYMODULE_VERSION=1.1 bundle exec rake beaker
+```
+
+Many CI systems make it easy to build a matrix with this.
+
+If no environment variables are present, the file is removed. It is not possible to store structured facts.
+
+This behavior can be disabled altogether:
+
+```ruby
+configure_beaker(configure_facts_from_env: false)
+```

lib/voxpupuli/acceptance/spec_helper_acceptance.rb

@@ -1,4 +1,31 @@
-def configure_beaker(modules: :metadata, &block)
+ENV_VAR_PREFIX = 'BEAKER_FACTER_'
+FACT_FILE = '/etc/facter/facts.d/voxpupuli-acceptance-env.json'
+
+def beaker_facts_from_env
+  facts = {}
+
+  ENV.each do |var, value|
+    next unless var.start_with?(ENV_VAR_PREFIX)
+
+    fact = var.sub(ENV_VAR_PREFIX, '').downcase
+    facts[fact] = value
+  end
+
+  facts
+end
+
+def write_beaker_facts_on(hosts)
+  beaker_facts = beaker_facts_from_env
+
+  if beaker_facts.any?
+    require 'json'
+    on(hosts, "mkdir -p #{File.dirname(FACT_FILE)} && cat <<VOXPUPULI_BEAKER_ENV_VARS > #{FACT_FILE}\n#{beaker_facts.to_json}\nVOXPUPULI_BEAKER_ENV_VARS")
+  else
+    on(hosts, "rm -f #{FACT_FILE}")
+  end
+end
+
+def configure_beaker(modules: :metadata, configure_facts_from_env: true, &block)
   ENV['PUPPET_INSTALL_TYPE'] ||= 'agent'
   ENV['BEAKER_PUPPET_COLLECTION'] ||= 'puppet6'
   ENV['BEAKER_debug'] ||= 'true'
@@ -33,6 +60,8 @@ def configure_beaker(modules: :metadata, &block)
         Voxpupupli::Acceptance::Fixtures.install_fixture_modules_on(hosts, fixture_modules)
       end
 
+      write_beaker_facts_on(hosts) if configure_facts_from_env
+
       if block
         hosts.each do |host|
           yield host