Merge pull request #9508 from chef/btm/knife-yaml

Add a `knife yaml convert` tool

2 files changed, 99 insertions, 0 deletions

diff --git a/lib/chef/knife/core/ui.rb b/lib/chef/knife/core/ui.rb
index 03b11a1b4d..893daa04e9 100644
--- a/lib/chef/knife/core/ui.rb
+++ b/lib/chef/knife/core/ui.rb
@@ -140,6 +140,14 @@ class Chef
         log("#{color("FATAL:", :red, :bold)} #{message}")
       end
 
+      # Print a message describing a fatal error and exit 1
+      #
+      # @param message [String] the text string
+      def fatal!(message)
+        fatal(message)
+        exit 1
+      end
+
       def color(string, *colors)
         if color?
           pastel.decorate(string, *colors)
diff --git a/lib/chef/knife/yaml_convert.rb b/lib/chef/knife/yaml_convert.rb
new file mode 100644
index 0000000000..a5b75e5691
--- /dev/null
+++ b/lib/chef/knife/yaml_convert.rb
@@ -0,0 +1,91 @@
+#
+# Author:: Bryan McLellan <btm@loftninjas.org>
+# Copyright:: Copyright 2020, Chef Software Inc.
+# License:: Apache License, Version 2.0
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+require "yaml"
+require_relative "../knife"
+class Chef::Knife::YamlConvert < Chef::Knife
+
+  banner "knife yaml convert YAML_FILENAME [RUBY_FILENAME]"
+
+  def run
+    if name_args.empty?
+      ui.fatal!("Please specify the file name of a YAML recipe to convert to Ruby")
+    elsif name_args.size >= 3
+      ui.fatal!("knife yaml convert YAML_FILENAME [RUBY_FILENAME]")
+    end
+
+    yaml_file = @name_args[0]
+    unless ::File.exist?(yaml_file) && ::File.readable?(yaml_file)
+      ui.fatal("Input YAML file '#{yaml_file}' does not exist or is unreadable")
+    end
+
+    ruby_file = if @name_args[1]
+                  @name_args[1] # use the specified output filename if provided
+                else
+                  if ::File.extname(yaml_file) == ".yml" || ::File.extname(yaml_file) == ".yaml"
+                    yaml_file.gsub(/\.(yml|yaml)$/, ".rb")
+                  else
+                    yaml_file + ".rb" # fall back to putting .rb on the end of whatever the yaml file was named
+                  end
+                end
+
+    if ::File.exist?(ruby_file)
+      ui.fatal!("Output Ruby file '#{ruby_file}' already exists")
+    end
+
+    yaml_contents = IO.read(yaml_file)
+
+    # YAML can contain multiple documents (--- is the separator), let's not support that.
+    if ::YAML.load_stream(yaml_contents).length > 1
+      ui.fatal!("YAML recipe '#{yaml_file}' contains multiple documents, only one is supported")
+    end
+
+    # Unfortunately, per the YAML spec, comments are stripped when we load, so we lose them on conversion
+    yaml_hash = ::YAML.safe_load(yaml_contents)
+    unless yaml_hash.is_a?(Hash) && yaml_hash.key?("resources")
+      ui.fatal!("YAML recipe '#{source_file}' must contain a top-level 'resources' hash (YAML sequence), i.e. 'resources:'")
+    end
+
+    ui.warn("No resources found in '#{yaml_file}'") if yaml_hash["resources"].size == 0
+
+    ::File.open(ruby_file, "w") do |file|
+      file.write(resource_hash_to_string(yaml_hash["resources"], yaml_file))
+    end
+    ui.info("Converted '#{yaml_file}' to '#{ruby_file}'")
+  end
+
+  # Converts a Hash of resources to a Ruby recipe
+  # returns a string ready to be written to a file or stdout
+  def resource_hash_to_string(resource_hash, filename)
+    ruby_contents = []
+    ruby_contents << "# Autoconverted recipe from #{filename}\n"
+
+    resource_hash.each do |r|
+      type = r.delete("type")
+      name = r.delete("name")
+
+      ruby_contents << "#{type} \"#{name}\" do"
+      r.each do |k, v|
+        ruby_contents << "  #{k} \"#{v}\""
+      end
+      ruby_contents << "end\n"
+    end
+
+    ruby_contents.join("\n")
+  end
+end