Initial commit

Author: Martin Roy

.travis.yml

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+language: bash
+
+script:
+  - bash test.sh

Dockerfile

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+FROM ruby:latest AS config-builder
+
+RUN mkdir /workspace/
+WORKDIR /workspace/
+
+COPY ./tools/* ./

README.md

@@ -1,2 +1,21 @@
 # ruby-yaml-erb-tools
+
 Tool set for parsing YAML and ERB files using ruby 
+
+## config.rb
+
+`Usage: config.rb --yaml config.yaml example.txt.erb`
+
+will output the parsed template using the yaml file
+
+## print_key.rb
+
+`Usage: print_key.rb --yaml config.yaml parent.child`
+
+will output the parsed value at the given path
+
+# Usage in dockerfiles
+
+You might need to build a container using templates... try multi stage build.
+
+See `test/Dockerfile` for an example

test.sh

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+#!/usr/bin/env bash -eux
+
+docker build --tag ruby-yaml-erb-tools-test .
+
+(cd test && docker build --tag processor .)
+
+[[ "This is the value" == "$(docker run -it --rm processor cat /processed/example.txt | tr -d '\r?\n')" ]]
+[[ "value" == "$(docker run -it --rm processor cat /processed/key.txt | tr -d '\r?\n')" ]]
+
+echo Test Pass!

test/Dockerfile

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+FROM ruby-yaml-erb-tools-test AS builder
+
+COPY config.yaml example.txt.erb ./
+
+RUN mkdir -p output/
+
+RUN /bin/bash -c "./config.rb --yaml config.yaml example.txt.erb > output/example.txt";
+
+RUN /bin/bash -c "./print_key.rb --yaml config.yaml parent.child > output/key.txt";
+
+
+FROM alpine
+
+COPY --from=builder /workspace/output/* /processed/

test/config.yaml

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+parent:
+  child: value

test/example.txt.erb

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+This is the <%= @parent['child'] %>

tools/config.rb

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+#!/usr/bin/env ruby
+require 'erb'
+require 'json'
+require 'yaml'
+require 'optparse'
+require 'ostruct'
+
+class ERBContext
+  def initialize(hash)
+    raise ArgumentError, 'hash must be a Hash object' unless hash.is_a?(::Hash)
+    hash.each do |key, value|
+      instance_variable_set :"@#{key}", value
+    end
+  end
+
+  def render(template)
+    template.result binding
+  end
+
+  class << self
+    def render(hash, template, safe_level = nil, trim_mode = nil, eoutvar = '_erbout')
+      tmpl = ::ERB.new(template, safe_level, trim_mode, eoutvar)
+      context = new(hash)
+      context.render tmpl
+    end
+  end
+end
+
+def file_or_stdin(args, stdin = ::STDIN)
+  if args.empty? || args.first == '-'
+    yield stdin
+  else
+    File.open args.first, 'r' do |f|
+      yield f
+    end
+  end
+end
+
+def main
+  options = OpenStruct.new
+
+  parser = OptionParser.new do |opts|
+    opts.banner = 'Usage: %s [options] file.erb' % $0
+    opts.on '-y', '--yaml=YAML-FILE', 'YAML file to populate local variables for the template' do |yaml_file|
+      File.open yaml_file, 'r' do |f|
+        options.yaml = YAML::load(f)
+      end
+    end
+  end
+
+  if (args = parser.parse(ARGV)).length > 1
+    STDERR.puts '%s: cannot render more than 1 file at a time!' % $0
+    exit 1
+  end
+
+  file_or_stdin args do |input|
+    puts ERBContext.render(options.yaml || {}, input.read, nil, '-')
+  end
+end
+
+main if __FILE__ == $0

tools/print_key.rb

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+#!/usr/bin/env ruby
+require 'yaml'
+require 'optparse'
+require 'ostruct'
+
+def key_or_stdin(args, stdin = ::STDIN)
+  if args.empty? || args.first == '-'
+    yield stdin
+  else
+    yield args.first
+  end
+end
+
+def main
+  options = OpenStruct.new
+
+  parser = OptionParser.new do |opts|
+    opts.banner = 'Usage: %s [options] key' % $0
+    opts.on '-y', '--yaml=YAML-FILE', 'YAML file to read the key from' do |yaml_file|
+      File.open yaml_file, 'r' do |f|
+        options.yaml = YAML::load(f)
+      end
+    end
+  end
+
+  if (args = parser.parse(ARGV)).length > 1
+    STDERR.puts '%s: cannot render more than 1 key at a time!' % $0
+    exit 1
+  end
+
+  key_or_stdin args do |input|
+    content = options.yaml
+    input.split(".").each do |part|
+      content = content[part]
+    end
+    puts content
+  end
+end
+
+main if __FILE__ == $0