1 files changed, 79 insertions, 0 deletions
diff --git a/lib/chef/config_fetcher.rb b/lib/chef/config_fetcher.rb
new file mode 100644
index 0000000000..80a313590b
--- /dev/null
+++ b/lib/chef/config_fetcher.rb
@@ -0,0 +1,79 @@
+require 'chef/application'
+require 'chef/chef_fs/path_utils'
+require 'chef/http/simple'
+require 'chef/json_compat'
+
+class Chef
+  class ConfigFetcher
+
+    attr_reader :config_location
+    attr_reader :config_file_jail
+
+    def initialize(config_location, config_file_jail)
+      @config_location = config_location
+      @config_file_jail = config_file_jail
+    end
+
+    def fetch_json
+      config_data = read_config
+      begin
+        Chef::JSONCompat.from_json(config_data)
+      rescue JSON::ParserError => error
+        Chef::Application.fatal!("Could not parse the provided JSON file (#{config_location}): " + error.message, 2)
+      end
+    end
+
+    def read_config
+      if remote_config?
+        fetch_remote_config
+      else
+        read_local_config
+      end
+    end
+
+    def fetch_remote_config
+      http.get("")
+    rescue SocketError, SystemCallError, Net::HTTPServerException => error
+      Chef::Application.fatal!("Cannot fetch config '#{config_location}': '#{error.class}: #{error.message}", 2)
+    end
+
+    def read_local_config
+      ::File.read(config_location)
+    rescue Errno::ENOENT => error
+      Chef::Application.fatal!("Cannot load configuration from #{config_location}", 2)
+    rescue Errno::EACCES => error
+      Chef::Application.fatal!("Permissions are incorrect on #{config_location}. Please chmod a+r #{config_location}", 2)
+    end
+
+    def config_missing?
+      return false if remote_config?
+
+      # Check if the config file exists, and check if it is underneath the config file jail
+      begin
+        real_config_file = Pathname.new(config_location).realpath.to_s
+      rescue Errno::ENOENT
+        return true
+      end
+
+      # If realpath succeeded, the file exists
+      return false if !config_file_jail
+
+      begin
+        real_jail = Pathname.new(config_file_jail).realpath.to_s
+      rescue Errno::ENOENT
+        Chef::Log.warn("Config file jail #{config_file_jail} does not exist: will not load any config file.")
+        return true
+      end
+
+      !Chef::ChefFS::PathUtils.descendant_of?(real_config_file, real_jail)
+    end
+
+    def http
+      Chef::HTTP::Simple.new(config_location)
+    end
+
+    def remote_config?
+      !!(config_location =~ %r{^(http|https)://})
+    end
+  end
+end