(#5132) Provide a query REST interface for inventory

This REST interface returns a list of nodes that match a fact query.
Fact queries can use (in)equality testing as a string comparison, and >,
<, >=, <= numerical comparisons.  Multiple tests can be done as AND
comparisons, not OR.

The fact queries need to be prefixed by facts, and the comparisons other
than equality are specified with a .comparison_type after the fact name.

This will be better explained in the REST documentation on the website.

Searches that don't match anything now return empty array instead of a
404 error.

7 files changed, 59 insertions, 3 deletions

diff --git a/lib/puppet/defaults.rb b/lib/puppet/defaults.rb
index ab127602b..c7bebf8f5 100644
--- a/lib/puppet/defaults.rb
+++ b/lib/puppet/defaults.rb
@@ -116,6 +116,7 @@ module Puppet
     :catalog_terminus => ["compiler", "Where to get node catalogs.  This is useful to change if, for instance,
       you'd like to pre-compile catalogs and store them in memcached or some other easily-accessed store."],
     :facts_terminus => [Puppet.application_name.to_s == "master" ? 'yaml' : 'facter', "The node facts terminus."],
+    :inventory_terminus => [ "$facts_terminus", "Should usually be the same as the facts terminus" ],
     :httplog => { :default => "$logdir/http.log",
       :owner => "root",
       :mode => 0640,
diff --git a/lib/puppet/indirector/indirection.rb b/lib/puppet/indirector/indirection.rb
index 309eed7b6..9095e48f8 100644
--- a/lib/puppet/indirector/indirection.rb
+++ b/lib/puppet/indirector/indirection.rb
@@ -238,6 +238,7 @@ class Puppet::Indirector::Indirection
     if result = terminus.search(request)
       raise Puppet::DevError, "Search results from terminus #{terminus.name} are not an array" unless result.is_a?(Array)
       result.each do |instance|
+        next unless instance.respond_to? :expiration
         instance.expiration ||= self.expiration
       end
       return result
diff --git a/lib/puppet/indirector/inventory/yaml.rb b/lib/puppet/indirector/inventory/yaml.rb
new file mode 100644
index 000000000..c6b1a14aa
--- /dev/null
+++ b/lib/puppet/indirector/inventory/yaml.rb
@@ -0,0 +1,47 @@
+require 'puppet/node/inventory'
+require 'puppet/indirector/yaml'
+
+class Puppet::Node::Inventory::Yaml < Puppet::Indirector::Yaml
+  desc "Return node names matching the fact query"
+
+  # Return the path to a given node's file.
+  def yaml_dir_path
+    base = Puppet.run_mode.master? ? Puppet[:yamldir] : Puppet[:clientyamldir]
+    File.join(base, 'facts', '*.yaml')
+  end
+
+  def node_matches?(facts, options)
+    options.each do |key, value|
+      type, name, operator = key.to_s.split(".")
+      operator ||= 'eq'
+
+      next unless type == "facts"
+      return false unless facts.values[name]
+
+      return false unless case operator
+      when "eq"
+        facts.values[name].to_s == value.to_s
+      when "le"
+        facts.values[name].to_f <= value.to_f
+      when "ge"
+        facts.values[name].to_f >= value.to_f
+      when "lt"
+        facts.values[name].to_f < value.to_f
+      when "gt"
+        facts.values[name].to_f > value.to_f
+      when "ne"
+        facts.values[name].to_s != value.to_s
+      end
+    end
+    return true
+  end
+
+  def search(request)
+    node_names = []
+    Dir.glob(yaml_dir_path).each do |file|
+      facts = YAML.load_file(file)
+      node_names << facts.name if node_matches?(facts, request.options)
+    end
+    node_names
+  end
+end
diff --git a/lib/puppet/network/http/api/v1.rb b/lib/puppet/network/http/api/v1.rb
index dd4612a14..2a4736365 100644
--- a/lib/puppet/network/http/api/v1.rb
+++ b/lib/puppet/network/http/api/v1.rb
@@ -57,9 +57,8 @@ module Puppet::Network::HTTP::API::V1
     # fix to not need this, and our goal is to move away from the complication
     # that leads to the fix being too long.
     return :singular if indirection == "facts"
-
-    # "status" really is singular
     return :singular if indirection == "status"
+    return :plural if indirection == "inventory"
 
     result = (indirection =~ /s$/) ? :plural : :singular
 
diff --git a/lib/puppet/network/http/handler.rb b/lib/puppet/network/http/handler.rb
index 61ae2d2fc..e5aa1c56f 100644
--- a/lib/puppet/network/http/handler.rb
+++ b/lib/puppet/network/http/handler.rb
@@ -116,7 +116,7 @@ module Puppet::Network::HTTP::Handler
   def do_search(indirection_request, request, response)
     result = indirection_request.model.search(indirection_request.key, indirection_request.to_hash)
 
-    if result.nil? or (result.is_a?(Array) and result.empty?)
+    if result.nil?
       return do_exception(response, "Could not find instances in #{indirection_request.indirection_name} with '#{indirection_request.key}'", 404)
     end
 
diff --git a/lib/puppet/node.rb b/lib/puppet/node.rb
index 2453cd1d5..e8d58e6be 100644
--- a/lib/puppet/node.rb
+++ b/lib/puppet/node.rb
@@ -3,6 +3,7 @@ require 'puppet/indirector'
 # A class for managing nodes, including their facts and environment.
 class Puppet::Node
   require 'puppet/node/facts'
+  require 'puppet/node/inventory'
   require 'puppet/node/environment'
 
   # Set up indirection, so that nodes can be looked for in
diff --git a/lib/puppet/node/inventory.rb b/lib/puppet/node/inventory.rb
new file mode 100644
index 000000000..fd99163b0
--- /dev/null
+++ b/lib/puppet/node/inventory.rb
@@ -0,0 +1,7 @@
+require 'puppet/node'
+require 'puppet/indirector'
+
+class Puppet::Node::Inventory
+  extend Puppet::Indirector
+  indirects :inventory, :terminus_setting => :inventory_terminus
+end