Feature string navigation for HTTP source API JSON

Allow HTTP API to place host array in arbitrary place defined as: hosts_location: a.b[0].c

Also support arrays in mapping keys: key: location[0].is.here[2]

3 files changed, 47 insertions, 16 deletions

diff --git a/.rubocop.yml b/.rubocop.yml
index 20567f4..c9feb24 100644
--- a/.rubocop.yml
+++ b/.rubocop.yml
@@ -30,6 +30,9 @@ Style/FormatStringToken:
 Style/RescueModifier:
   Enabled: false
 
+Style/MultilineBlockChain:
+  Enabled: false
+
 # Do not attempt to police vendored code, and exclude special cases
 AllCops:
   Exclude:
diff --git a/lib/oxidized/source/http.rb b/lib/oxidized/source/http.rb
index 55dcd4c..bf1e74c 100644
--- a/lib/oxidized/source/http.rb
+++ b/lib/oxidized/source/http.rb
@@ -39,21 +39,20 @@ module Oxidized
 
       response = http.request(request)
       data = JSON.parse(response.body)
+      data = string_navigate(data, @cfg.hosts_location) if @cfg.hosts_location?
       data.each do |node|
         next if node.empty?
         # map node parameters
         keys = {}
         @cfg.map.each do |key, want_position|
-          want_positions = want_position.split('.')
-          keys[key.to_sym] = node_var_interpolate node.dig(*want_positions)
+          keys[key.to_sym] = node_var_interpolate string_navigate(node, want_position)
         end
         keys[:model] = map_model keys[:model] if keys.has_key? :model
 
         # map node specific vars
         vars = {}
         @cfg.vars_map.each do |key, want_position|
-          want_positions = want_position.split('.')
-          vars[key.to_sym] = node_var_interpolate node.dig(*want_positions)
+          vars[key.to_sym] = node_var_interpolate string_navigate(node, want_position)
         end
         keys[:vars] = vars unless vars.empty?
 
@@ -61,20 +60,17 @@ module Oxidized
       end
       nodes
     end
-  end
-end
 
-if RUBY_VERSION < '2.3'
-  class Hash
-    def dig(key, *rest)
-      value = self[key]
-      if value.nil? || rest.empty?
-        value
-      elsif value.respond_to?(:dig)
-        value.dig(*rest)
-      else # foo.bar.baz (bar exist but is not hash)
-        return nil
+    private
+
+    def string_navigate object, wants
+      wants.split(".").map do |want|
+        head, match, _tail = want.partition(/\[\d+\]/)
+        match.empty? ? head : [head, match[1..-2].to_i]
+      end.flatten.each do |want|
+        object = object[want] if object.respond_to? :each
       end
+      object
     end
   end
 end
diff --git a/spec/source/http_spec.rb b/spec/source/http_spec.rb
new file mode 100644
index 0000000..d3df551
--- /dev/null
+++ b/spec/source/http_spec.rb
@@ -0,0 +1,32 @@
+require 'spec_helper'
+require 'oxidized/source/http'
+
+describe Oxidized::HTTP do
+  before(:each) do
+    Oxidized.asetus = Asetus.new
+    Oxidized.setup_logger
+  end
+
+  describe "#string_navigate" do
+    h1 = {}
+    h1["inventory"] = [{ "ip" => "10.10.10.10" }]
+    h1["jotain"] = { "2" => "jotain" }
+    it "should be able to navigate multilevel-hash" do
+      http = Oxidized::HTTP.new
+      http.class.must_equal Oxidized::HTTP
+      http.send(:string_navigate, h1, "jotain.2").must_equal "jotain"
+    end
+    it "should be able to navigate multilevel-hash" do
+      Oxidized::HTTP.new.send(:string_navigate, h1, "jotain.2").must_equal "jotain"
+    end
+    it "should be able to navigate hash/array combination" do
+      Oxidized::HTTP.new.send(:string_navigate, h1, "inventory[0].ip").must_equal "10.10.10.10"
+    end
+    it "should return nil on non-existing string key" do
+      Oxidized::HTTP.new.send(:string_navigate, h1, "jotain.3").must_equal nil
+    end
+    it "should return nil on non-existing array index" do
+      Oxidized::HTTP.new.send(:string_navigate, h1, "inventory[3]").must_equal nil
+    end
+  end
+end