(#11583) Add basic coverage to the ec2 fact

The only goal here is to add coverage based on the current behaviour so we have
something to work with when other contributors work on the code.

We've only added very simple bad-case testing (ie. timeout) to match the code
at the moment, however the good-case testing covers flat & structured meta-data
and user-data. While we test both ec2 and eucalyptus cases, we only check basic
user-data for eucalyptus for now (as the code is the same in both cases).

spec/unit/ec2_spec.rb

@@ -0,0 +1,149 @@
+#!/usr/bin/env rspec
+
+require 'spec_helper'
+
+describe "ec2 facts" do
+  let(:api_prefix) { "http://169.254.169.254" }
+
+  describe "when running on ec2" do
+    before :each do
+      # Return fake kernel
+      Facter.stubs(:value).with(:kernel).returns("Linux")
+
+      # Return something upon connecting to the root so the EC2 code continues
+      # with its evaluation.
+      Object.any_instance.expects(:open).with("#{api_prefix}:80/").\
+        at_least_once.returns("2008-02-01\nlatest")
+
+      # Return a non-eucalyptus mac address
+      Facter.expects(:value).with(:macaddress).\
+        at_least_once.returns("12:31:39:04:5A:34")
+
+      # Fake EC2 arp response
+      ec2arp = "? (10.240.93.1) at fe:ff:ff:ff:ff:ff [ether] on eth0\n"
+      Facter::Util::Resolution.expects(:exec).with("arp -an").\
+        at_least_once.returns(ec2arp)
+    end
+
+    it "should create flat meta-data facts" do
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/meta-data/").\
+        at_least_once.returns(StringIO.new("foo"))
+
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/meta-data/foo").\
+        at_least_once.returns(StringIO.new("bar"))
+
+      # No user-data
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/user-data/").\
+        at_least_once.returns(StringIO.new(""))
+
+      Facter.collection.loader.load(:ec2)
+      Facter.fact(:ec2_foo).value.should == "bar"
+    end
+
+    it "should create flat meta-data facts with comma seperation" do
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/meta-data/").\
+        at_least_once.returns(StringIO.new("foo"))
+
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/meta-data/foo").\
+        at_least_once.returns(StringIO.new("bar\nbaz"))
+
+      # No user-data
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/user-data/").\
+        at_least_once.returns(StringIO.new(""))
+
+      Facter.collection.loader.load(:ec2)
+      Facter.fact(:ec2_foo).value.should == "bar,baz"
+    end
+
+    it "should create structured meta-data facts" do
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/meta-data/").\
+        at_least_once.returns(StringIO.new("foo/"))
+
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/meta-data/foo/").\
+        at_least_once.returns(StringIO.new("bar"))
+
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/meta-data/foo/bar").\
+        at_least_once.returns(StringIO.new("baz"))
+
+      # No user-data
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/user-data/").\
+        at_least_once.returns(StringIO.new(""))
+
+      Facter.collection.loader.load(:ec2)
+      Facter.fact(:ec2_foo_bar).value.should == "baz"
+    end
+
+    it "should create ec2_user_data fact" do
+      # No meta-data
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/meta-data/").\
+        at_least_once.returns(StringIO.new(""))
+
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/user-data/").\
+        at_least_once.returns(StringIO.new("test"))
+
+      Facter.collection.loader.load(:ec2)
+      Facter.fact(:ec2_userdata).value.should == ["test"]
+    end
+  end
+
+  describe "when running on eucalyptus" do
+    before :each do
+      # Return fake kernel
+      Facter.stubs(:value).with(:kernel).returns("Linux")
+
+      # Return something upon connecting to the root so the EC2 code continues
+      # with its evaluation.
+      Object.any_instance.expects(:open).with("#{api_prefix}:80/").\
+        at_least_once.returns("2008-02-01\nlatest")
+
+      # Return a eucalyptus mac address
+      Facter.expects(:value).with(:macaddress).\
+        at_least_once.returns("d0:0d:1a:b0:a1:00")
+    end
+
+    it "should create ec2_user_data fact" do
+      # No meta-data
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/meta-data/").\
+        at_least_once.returns(StringIO.new(""))
+
+      Object.any_instance.expects(:open).\
+        with("#{api_prefix}/2008-02-01/user-data/").\
+        at_least_once.returns(StringIO.new("test"))
+
+      Facter.collection.loader.load(:ec2)
+      Facter.fact(:ec2_userdata).value.should == ["test"]
+    end
+  end
+
+  describe "when ec2 url times out" do
+    before :each do
+      # Return fake kernel
+      Facter.stubs(:value).with(:kernel).returns("Linux")
+
+      # Emulate a timeout when connecting by throwing an exception
+      Object.any_instance.expects(:open).with("#{api_prefix}:80/").\
+        at_least_once.throws(Timeout::Error)
+
+      # Return a eucalyptus mac address
+      Facter.expects(:value).with(:macaddress).\
+        at_least_once.returns("d0:0d:1a:b0:a1:00")
+    end
+
+    it "should not raise exception" do
+      expect { Facter.collection.loader.load(:ec2) }.to_not raise_error
+    end
+  end
+end