Allow --hostname to receive a comma separated list of hosts and work on them in parallel

.travis.yml

@@ -3,7 +3,6 @@
 language: ruby
 install: true
 script: "script/cibuild"
-before_install: gem install bundler
 
 matrix:
   include:

doc/optionsref.md

@@ -9,7 +9,8 @@
 
 ```
 Usage: octocatalog-diff [command line options]
-    -n, --hostname HOSTNAME          Use PuppetDB facts from last run of hostname
+    -n HOSTNAME1[,HOSTNAME2[,...]],  Use PuppetDB facts from last run of a hostname or a comma separated list of multiple hostnames
+        --hostname
         --basedir DIRNAME            Use an alternate base directory (git checkout of puppet repository)
     -f, --from FROM_BRANCH           Branch you are coming from
     -t, --to TO_BRANCH               Branch you are going to
@@ -856,14 +857,17 @@ Puppet control repo template, the value of this should be 'hieradata', which is
 
   <tr>
     <td valign=top>
-      <pre><code>-n HOSTNAME
---hostname HOSTNAME</code></pre>
+      <pre><code>-n HOSTNAME1[,HOSTNAME2[,...]]
+--hostname HOSTNAME1[,HOSTNAME2[,...]]</code></pre>
     </td>
     <td valign=top>
-      Use PuppetDB facts from last run of hostname
+      Use PuppetDB facts from last run of a hostname or a comma separated list of multiple hostnames
     </td>
     <td valign=top>
-      Set hostname, which is used to look up facts in PuppetDB, and in the header of diff display. (<a href="../lib/octocatalog-diff/cli/options/hostname.rb">hostname.rb</a>)
+      Set hostname, which is used to look up facts in PuppetDB, and in the header of diff display.
+This option can recieve a single hostname, or a comma separated list of
+multiple hostnames, which are split into an Array. Multiple hostnames do not
+work with the `catalog-only` or `bootstrap-then-exit` options. (<a href="../lib/octocatalog-diff/cli/options/hostname.rb">hostname.rb</a>)
     </td>
   </tr>
 

lib/octocatalog-diff/cli.rb

@@ -11,6 +11,7 @@
 require_relative 'version'
 
 require 'logger'
+require 'parallel'
 require 'socket'
 
 module OctocatalogDiff
@@ -116,16 +117,34 @@ def self.cli(argv = ARGV, logger = Logger.new(STDERR), opts = {})
       end
 
       # Compile catalogs and do catalog-diff
-      catalog_diff = OctocatalogDiff::API::V1.catalog_diff(options.merge(logger: logger))
-      diffs = catalog_diff.diffs
-
-      # Display diffs
-      printer_obj = OctocatalogDiff::Cli::Printer.new(options, logger)
-      printer_obj.printer(diffs, catalog_diff.from.compilation_dir, catalog_diff.to.compilation_dir)
+      node_set = options.delete(:node)
+      node_set = [node_set] unless node_set.is_a?(Array)
+      catalog_diff = nil
+      all_diffs = []
+
+      # run multiple node diffs in parallel
+      Parallel.map(node_set, in_threads: 4) do |node|
+        options[:node] = node
+        catalog_diff = OctocatalogDiff::API::V1.catalog_diff(options.merge(logger: logger))
+        diffs = catalog_diff.diffs
+
+        # Display diffs
+        printer_obj = OctocatalogDiff::Cli::Printer.new(options, logger)
+        printer_obj.printer(diffs, catalog_diff.from.compilation_dir, catalog_diff.to.compilation_dir)
+
+        # Append any diffs for final exit status
+        all_diffs << diffs
+      end
 
       # Return the resulting diff object if requested (generally for testing) or otherwise return exit code
       return catalog_diff if opts[:INTEGRATION]
-      diffs.any? ? EXITCODE_SUCCESS_WITH_DIFFS : EXITCODE_SUCCESS_NO_DIFFS
+
+      all_diffs.each do |diff|
+        next unless diff.any?
+        return EXITCODE_SUCCESS_WITH_DIFFS
+      end
+
+      EXITCODE_SUCCESS_NO_DIFFS
     end
 
     # Parse command line options with 'optparse'. Returns a hash with the parsed arguments.

lib/octocatalog-diff/cli/options.rb

@@ -11,7 +11,7 @@ class Cli
     # This class contains the option parser. 'parse_options' is the external entry point.
     class Options
       # The usage banner.
-      BANNER = 'Usage: catalog-diff -n <hostname> [-f <from environment>] [-t <to environment>]'.freeze
+      BANNER = 'Usage: catalog-diff -n <hostname>[,<hostname>...] [-f <from environment>] [-t <to environment>]'.freeze
 
       # An error class specifically for passing information to the document build task.
       class DocBuildError < RuntimeError; end

lib/octocatalog-diff/cli/options/hostname.rb

@@ -1,15 +1,26 @@
 # frozen_string_literal: true
 
 # Set hostname, which is used to look up facts in PuppetDB, and in the header of diff display.
+# This option can recieve a single hostname, or a comma separated list of
+# multiple hostnames, which are split into an Array. Multiple hostnames do not
+# work with the `catalog-only` or `bootstrap-then-exit` options.
 # @param parser [OptionParser object] The OptionParser argument
 # @param options [Hash] Options hash being constructed; this is modified in this method.
 
 OctocatalogDiff::Cli::Options::Option.newoption(:hostname) do
   has_weight 1
 
   def parse(parser, options)
-    parser.on('--hostname HOSTNAME', '-n', 'Use PuppetDB facts from last run of hostname') do |hostname|
-      options[:node] = hostname
+    parser.on(
+      '--hostname HOSTNAME1[,HOSTNAME2[,...]]',
+      '-n',
+      'Use PuppetDB facts from last run of a hostname or a comma separated list of multiple hostnames'
+    ) do |hostname|
+      options[:node] = if hostname.include?(',')
+        hostname.split(',')
+      else
+        hostname
+      end
     end
   end
 end

octocatalog-diff.gemspec

@@ -27,6 +27,7 @@ EOF
   s.add_runtime_dependency 'diffy', '>= 3.1.0'
   s.add_runtime_dependency 'httparty', '>= 0.11.0'
   s.add_runtime_dependency 'hashdiff', '>= 0.3.0'
+  s.add_runtime_dependency 'parallel', '>= 1.12.0'
   s.add_runtime_dependency 'rugged', '>= 0.25.0b2'
 
   s.add_development_dependency 'rspec', '~> 3.4.0'

spec/octocatalog-diff/tests/cli/options/hostname_spec.rb

@@ -8,5 +8,10 @@
       result = run_optparse(['-n', 'octonode.rspec'])
       expect(result.fetch(:node, 'key-not-defined')).to eq('octonode.rspec')
     end
+
+    it 'should set multiple nodes when passed a series of nodes' do
+      result = run_optparse(['-n', 'octonode1.rspec,octonode2.rspec'])
+      expect(result.fetch(:node, 'key-not-defined')).to eq(%w[octonode1.rspec octonode2.rspec])
+    end
   end
 end