(PF-2332) Add pdk env subcommand

Adds an experimental `pdk env` subcommand, which aids in setting a CLI context for a specified version of Puppet.

lib/pdk/cli.rb

@@ -159,6 +159,7 @@ def self.puppet_dev_option(dsl)
   require 'pdk/cli/build'
   require 'pdk/cli/config'
   require 'pdk/cli/convert'
+  require 'pdk/cli/env'
   require 'pdk/cli/get'
   require 'pdk/cli/new'
   require 'pdk/cli/set'

lib/pdk/cli/env.rb

@@ -0,0 +1,52 @@
+module PDK::CLI
+  @env_cmd = @base_cmd.define_command do
+    name 'env'
+    usage _('env')
+    summary _('(Experimental) Output environment variables for specific Puppet context')
+    description _(<<-EOF
+[experimental] Aids in setting a CLI context for a specified version of Puppet by outputting export commands for necessary environment variables.
+EOF
+                 )
+
+    PDK::CLI.puppet_version_options(self)
+    PDK::CLI.puppet_dev_option(self)
+
+    run do |opts, args, _cmd|
+      require 'pdk/util'
+      require 'pdk/util/ruby_version'
+
+      PDK::CLI::Util.validate_puppet_version_opts(opts)
+
+      PDK::CLI::Util.analytics_screen_view('env')
+
+      # Ensure that the correct Ruby is activated before running command.
+      puppet_env = PDK::CLI::Util.puppet_from_opts_or_env(opts)
+      PDK::Util::RubyVersion.use(puppet_env[:ruby_version])
+
+      resolved_env = {
+        'PDK_RESOLVED_PUPPET_VERSION': puppet_env[:gemset][:puppet],
+        'PDK_RESOLVED_RUBY_VERSION': puppet_env[:ruby_version],
+      }
+
+      resolved_env['GEM_HOME'] = PDK::Util::RubyVersion.gem_home
+      gem_path = PDK::Util::RubyVersion.gem_path
+      resolved_env['GEM_PATH'] = gem_path.empty? ? resolved_env['GEM_HOME'] : gem_path
+
+      # Make sure invocation of Ruby prefers our private installation.
+      package_binpath = PDK::Util.package_install? ? File.join(PDK::Util.pdk_package_basedir, 'bin') : nil
+
+      resolved_env['PATH'] = [
+        PDK::Util::RubyVersion.bin_path,
+        File.join(resolved_env['GEM_HOME'], 'bin'),
+        PDK::Util::RubyVersion.gem_paths_raw.map { |gem_path_raw| File.join(gem_path_raw, 'bin') },
+        package_binpath,
+        PDK::Util::Env['PATH'],
+      ].compact.flatten.join(File::PATH_SEPARATOR)
+
+      resolved_env.each do |var, val|
+        puts "export #{var}=\"#{val}\""
+      end
+      exit 0
+    end
+  end
+end

spec/unit/pdk/cli/env_spec.rb

@@ -0,0 +1,90 @@
+require 'spec_helper'
+require 'pdk/cli'
+
+describe 'Running `pdk env`' do
+  let(:command_args) { ['env'] }
+  let(:command_result) { { exit_code: 0 } }
+
+  context 'when it calls env successfully' do
+    after(:each) do
+      expect {
+        PDK::CLI.run(command_args)
+      }.to exit_zero
+    end
+
+    before(:each) do
+      allow(PDK::Util::RubyVersion).to receive(:gem_home).and_return("/opt/puppetlabs/pdk/share/cache/ruby/2.4.0")
+      allow(PDK::Util::RubyVersion).to receive(:gem_path).and_return("/opt/puppetlabs/pdk/private/ruby/2.4.3/lib")
+      allow(PDK::Util::RubyVersion).to receive(:bin_path).and_return("/opt/puppetlabs/pdk/private/ruby/2.4.3/bin")
+      allow(PDK::Util::RubyVersion).to receive(:gem_paths_raw).and_return(["/opt/puppetlabs/pdk/private/ruby/2.4.3/lib"])
+      allow(PDK::Util::Env).to receive(:[]).and_call_original
+      allow(PDK::Util::Env).to receive(:[]).with('PATH').and_return('/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin')
+
+      allow(PDK::CLI::Util).to receive(:puppet_from_opts_or_env)
+        .and_return(ruby_version: '2.4.3', gemset: { puppet: '5.4.0' })
+      allow(PDK::Util::RubyVersion).to receive(:use)
+    end
+
+    context 'and called with no arguments' do
+      it 'sends a "env" screen view to analytics' do
+        expect(analytics).to receive(:screen_view).with(
+          'env',
+          output_format: 'default',
+          ruby_version:  RUBY_VERSION,
+        )
+      end
+
+      it 'outputs export commands for environment variables' do
+        output_regexes = [
+          /export PDK_RESOLVED_PUPPET_VERSION="\d\.\d+\.\d+"/,
+          /export PDK_RESOLVED_RUBY_VERSION="\d\.\d+\.\d+"/,
+          /export GEM_HOME=.*/,
+          /export GEM_PATH=.*/,
+          /export PATH=.*/
+        ]
+
+        output_regexes.each do |regex|
+          expect($stdout).to receive(:puts).with(a_string_matching(regex))
+        end
+      end
+    end
+
+    context 'and called with a puppet version' do
+      let(:command_args) { super() + %w[--puppet-version=6] }
+
+      it 'outputs export commands for environment variables' do
+        output_regexes = [
+          /export PDK_RESOLVED_PUPPET_VERSION="\d\.\d+\.\d+"/,
+          /export PDK_RESOLVED_RUBY_VERSION="\d\.\d+\.\d+"/,
+          /export GEM_HOME=.*/,
+          /export GEM_PATH=.*/,
+          /export PATH=.*/
+        ]
+
+        output_regexes.each do |regex|
+          expect($stdout).to receive(:puts).with(a_string_matching(regex))
+        end
+      end
+
+      # context 'with a conflicting environment variable' do
+      #   before(:each) do
+      #     allow(PDK::Util::Env).to receive(:[]).with('PDK_PUPPET_VERSION').and_return('5.1')
+      #   end
+
+      #   it 'outputs export commands for environment variables' do
+      #     output_regexes = [
+      #       /export PDK_RESOLVED_PUPPET_VERSION="\d\.\d+\.\d+"/,
+      #       /export PDK_RESOLVED_RUBY_VERSION="\d\.\d+\.\d+"/,
+      #       /export GEM_HOME=.*/,
+      #       /export GEM_PATH=.*/,
+      #       /export PATH=.*/
+      #     ]
+
+      #     output_regexes.each do |regex|
+      #       expect($stdout).to receive(:puts).with(a_string_matching(regex))
+      #     end
+      #   end
+      # end
+    end
+  end
+end