Merge pull request #71 from jgnagy/feature/preprocess-rendering

Adding render option to apply preprocessing

Gemfile.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    skull_island (2.3.3)
+    skull_island (2.3.4)
       deepsort (~> 0.4)
       erubi (~> 1.8)
       linguistics (~> 2.1)

README.md

@@ -56,6 +56,7 @@ Commands:
   skull_island help [COMMAND]                          # Describe available commands or one specific command
   skull_island import [OPTIONS] [INPUT|-]              # Import a configuration from INPUT
   skull_island migrate [OPTIONS] [INPUT|-] [OUTPUT|-]  # Migrate an older config from INPUT to OUTPUT
+  skull_island render [INPUT|-]                        # Render out preprocessed YAML for troubleshooting
   skull_island reset                                   # Fully reset a gateway (removing all config)
   skull_island version                                 # Display the current installed version of skull_island
 
@@ -149,6 +150,16 @@ To use this functionality, either add the `project` key to your configuration fi
 
 When using the `project` feature of Skull Island, the CLI tool will automatically clean up old resources no longer found in your config file. This is, in fact, the _only_ circumstance under which this tool actually removes resources. Use this feature with care, as it can delete large swaths of your configuration if used incorrectly. It is **critical** that this value is unique since this project functionality is used to delete resources.
 
+#### Troubleshooting Import Failures
+
+If you're having trouble importing some YAML -- especially if you've done a lot of templating or have a lot of embedded ruby in your template -- you can use the `render` command to just output the raw, preprocessed YAML that Skull Island would attempt to import:
+
+```sh
+skull_island render /path/to/some/template.yml
+```
+
+This is safe to do on your local machine since it doesn't connect to a gateway. It will leave `lookup` functions but otherwise will leave the YAML without embedded ruby. This can then be linted with any YAML linter to help discover YAML-related formatting issues, etc., that cause import issues.
+
 ### Migrating
 
 With Skull Island, it is possible to migrate a configuration from a 0.14.x, 1.1.x, 1.2.x, 1.4.x, or 1.5.x gateway to the most recent compatible gateway. If you have a previous export, you can just run `skull_island migrate /path/to/export.yml` and you'll receive a 2.3 compatible config on standard out. If you'd prefer, you can have that config written to a file as well (just like the export command) like so:

lib/skull_island/cli.rb

@@ -132,6 +132,12 @@ def reset
       ].each { |clname| reset_class(clname, options['project']) }
     end
 
+    desc('render [INPUT|-]', 'Render out preprocessed YAML for troubleshooting')
+    def render(input_file = '-')
+      raw ||= acquire_input(input_file, options['verbose'])
+      puts erb_preprocess(raw)
+    end
+
     desc('version', 'Display the current installed version of skull_island')
     def version
       puts "SkullIsland Version: #{SkullIsland::VERSION}"

lib/skull_island/version.rb

@@ -4,6 +4,6 @@ module SkullIsland
   VERSION = [
     2, # Major
     3, # Minor
-    3  # Patch
+    4  # Patch
   ].join('.')
 end