Building CLI Apps for Everyone - RubyConf 2015

Video: https://www.youtube.com/watch?v=zv_bCpOCXxo

Many projects rely on command-line tools to provide an efficient and powerful interface to work.

Building tools for everyone can be difficult, because of conflicting environment or OS.

How can we build command-line apps that work for everyone and still write Ruby?

This talk will discuss how to use mruby-cli to build cross-platform apps in Ruby.

Our goal will be to build a CLI app using mruby and produce a self-contained binary that can be shipped to end users.

Since mruby is designed to be embedded and statically compiled, it's also really good at packaging ruby code.

Transcript

1. Building CLI Apps for Everyone
2. Terence Lee @hone02
3. Austin, TX
4. Austin, TX
5. #rubykaraoke
7. @aspleenic
9. Packaging in Ruby
10. story of the heroku toolbelt
11. gem install heroku
12. Requires Ruby to be installed
13. Can't guarantee same version of ruby locally
15. Packaging was a nightmare
16. hk
18. require in ruby is slow
21. Traveling Ruby • no need to rewrite your app • packages your app as a directory • runtime packaging is taken care of • can leverage rubygems ecosystem • native gems limited to precompiled exts
22. sferik
23. No great packaging story
24. I want to build things in Ruby
27. Picking Ruby shouldn't be a technical limitation
28. Making Packaging Possible
29. mruby-cli http://github.com/hone/mruby-cli
30. writing in ruby
31. mrblib ├── [4.0K] mrblib │ ├── [4.0K] mruby-cli │ │ ├── [ 697] cli.rb │ │ ├── [ 424] help.rb │ │ ├── [ 403] option.rb │ │ ├── [1022] options.rb │ │ ├── [8.0K] setup.rb │ │ ├── [ 238] util.rb │ │ └── [ 206] version.rb │ └── [ 53] mruby-cli.rb
32. performance is a feature
33. MRI # hello_world.rb puts 'Hello World'
34. MRI # hello_world.rb puts 'Hello World' $ time ruby hello.rb Hello World real 0m0.041s user 0m0.028s sys 0m0.008s
35. mruby-cli # mrblib/hello.rb def __main__(argv) puts "Hello World" end
36. mruby-cli # mrblib/hello.rb def __main__(argv) puts "Hello World" end $ time mruby/build/host/bin/hello Hello World real 0m0.003s user 0m0.000s sys 0m0.000s
37. No require
38. a single binary for every major platform
39. $ docker-compose run compile Build summary: ================================================ Config Name: x86_64-pc-linux-gnu Output Directory: build/host Included Gems: mruby-print - standard print/puts/p mruby-sprintf - standard Kernel#sprintf method mruby-time - standard Time class mruby-io mruby-mtest hello - hello - Binaries: hello ================================================
40. ================================================ Config Name: x86_64-apple-darwin14 Output Directory: build/x86_64-apple-darwin14 Included Gems: mruby-print - standard print/puts/p mruby-sprintf - standard Kernel#sprintf method mruby-time - standard Time class mruby-io mruby-mtest hello - hello - Binaries: hello ================================================
41. ================================================ Config Name: x86_64-w64-mingw32 Output Directory: build/x86_64-w64-mingw32 Included Gems: mruby-print - standard print/puts/p mruby-sprintf - standard Kernel#sprintf method mruby-time - standard Time class mruby-io mruby-mtest hello - hello - Binaries: hello ================================================
42. $ ls -nlh mruby-cli | awk '{print $5}' 421K
43. simple setup
44. Docker FROM hone/mruby-cli
45. Hello World Example $ mruby-cli --setup hello
46. Hello World Example $ mruby-cli --setup hello $ cd hello
47. Hello World Example $ mruby-cli --setup hello $ cd hello $ docker-compose run compile
48. Hello World Example $ mruby-cli --setup hello $ cd hello $ docker-compose run compile $ docker-compose run shell # mruby/build/host/bin/hello
49. Hello World Example $ mruby-cli --setup hello $ cd hello $ docker-compose run compile $ docker-compose run shell # mruby/build/host/bin/hello Hello World
50. Hello World Example $ mruby/bin/mruby-cli --setup hello create .gitignore create mrbgem.rake create build_config.rb create Rakefile create Dockerfile create docker-compose.yml create tools/ create tools/hello/ create tools/hello/hello.c create mrblib/ create mrblib/hello.rb create mrblib/hello/ create mrblib/hello/version.rb create bintest/ create bintest/hello.rb create test/ create test/test_hello.rb
51. mruby
52. mruby is the lightweight implementation of the Ruby language complying with part of the ISO standard. mruby can be linked and embedded within your application.
53. used in the wild https://github.com/ximenzi/openwrt-mruby
54. Contributors
55. Differences with MRI
56. no built in File Socket I/O
57. not threadsafe
58. no thread no fork
59. subset of Ruby 1.9
60. procs blocks DHH freedom patching meta programming literals
61. Executing mruby code
62. Interpret (*.rb) $ mruby/bin/mruby -e "puts 'Hello World'" Hello World $ mruby/bin/mruby hello_world.rb Hello World
63. Interactive (mirb) $ mruby/bin/mirb mirb - Embeddable Interactive Ruby Shell > puts 'Hello World' Hello World => nil
64. bytecode (*.mrb) $ mruby/bin/mrbc hello_world.rb
65. bytecode (*.mrb) $ mruby/bin/mrbc hello_world.rb $ ls hello_world.* hello_world.rb hello_world.mrb
66. bytecode (*.mrb) $ mruby/bin/mrbc hello_world.rb $ ls hello_world.* hello_world.rb hello_world.mrb $ mruby/bin/mruby -b hello_world.mrb Hello World
67. Binary C Code (*.c) $ mruby/bin/mrbc -o hello_world.c - Bhello_world hello_world.rb $ cat hello_world.c /* dumped in little endian order. use `mrbc -E` option for big endian CPU. */ #include <stdint.h> const uint8_t #if defined __GNUC__ __attribute__((aligned(4))) #elif defined _MSC_VER __declspec(align(4)) #endif hello_world[] = { 0x45,0x54,0x49,0x52,0x30,0x30,0x30,0x33,0xcb,0xa4,0x00, 0x00,0x00,0x65,0x4d,0x41,...}; This is an FYI No need to read this C code
68. int main(void) { mrb_state *mrb = mrb_open(); mrbc_context *c; mrb_value v; c = mrbc_context_new(mrb); mrb_load_irep_cxt(mrb, hello_world, c); mrbc_context_free(mrb, c); return 0; }
69. int main(void) { mrb_state *mrb = mrb_open(); mrbc_context *c; mrb_value v; c = mrbc_context_new(mrb); mrb_load_irep_cxt(mrb, hello_world, c); mrbc_context_free(mrb, c); return 0; }
70. tools/hello/hello.c #include <stdlib.h> #include <stdio.h> /* Include the mruby header */ #include <mruby.h> #include <mruby/array.h> int main(int argc, char *argv[]) { mrb_state *mrb = mrb_open(); mrb_value ARGV = mrb_ary_new_capa(mrb, argc); int i; int return_value; for (i = 0; i < argc; i++) { mrb_ary_push(mrb, ARGV, mrb_str_new_cstr(mrb, argv[i])); } mrb_define_global_const(mrb, "ARGV", ARGV); // call __main__(ARGV) mrb_funcall(mrb, mrb_top_self(mrb), "__main__", 1, ARGV); return_value = EXIT_SUCCESS; if (mrb->exc) { mrb_print_error(mrb); return_value = EXIT_FAILURE; } mrb_close(mrb); return return_value; } This is an FYI No need to read this C code
71. # mrblib/hello.rb def __main__(argv) puts "Hello World" end
72. mrblib ├── [4.0K] mrblib │ ├── [4.0K] mruby-cli │ │ ├── [ 697] cli.rb │ │ ├── [ 424] help.rb │ │ ├── [ 403] option.rb │ │ ├── [1022] options.rb │ │ ├── [8.0K] setup.rb │ │ ├── [ 238] util.rb │ │ └── [ 206] version.rb │ └── [ 53] mruby-cli.rb
73. Rakefile $ rake -T rake all # build all targets... rake clean # clean all built.. rake compile # compile all the binaries rake release # generate release tarballs rake test # run all tests rake test:bintest # run integration tests rake test:mtest # run mruby & unit tests
74. build_config.rb MRuby::Build.new do |conf| toolchain :gcc conf.enable_bintest conf.enable_debug conf.enable_test gem_config(conf) end
75. build_config.rb MRuby::CrossBuild.new('x86_64-apple-darwin14') do |conf| toolchain :clang [conf.cc, conf.linker].each do |cc| cc.command = 'x86_64-apple-darwin14-clang' end conf.cxx.command = 'x86_64-apple-darwin14-clang++' conf.archiver.command = 'x86_64-apple-darwin14-ar' conf.build_target = 'x86_64-pc-linux-gnu' conf.host_target = 'x86_64-apple-darwin14' gem_config(conf) end
76. $ docker-compose run compile Build summary: ================================================ Config Name: host Output Directory: build/host Binaries: mrbc Included Gems: mruby-print - standard print/puts/p mruby-sprintf - standard Kernel#sprintf method mruby-time - standard Time class mruby-io mruby-mtest hello - hello - Binaries: hello mruby-compiler - mruby compiler library mruby-bin-mrbc - mruby compiler executable ================================================
77. mrbgem.rake MRuby::Gem::Specification.new('hello') do |spec| spec.license = 'MIT' spec.authors = ['Terence Lee'] spec.summary = 'hello world' spec.bins = ['hello'] spec.add_dependency 'mruby-print', :core => 'mruby- print' spec.add_dependency 'mruby-mtest', :mgem => 'mruby- mtest' spec.add_dependency 'mruby-yaml', :github => 'hone/mruby-yaml' end
78. mrbgem.rake MRuby::Gem::Specification.new('hello') do |spec| spec.license = 'MIT' spec.authors = ['Terence Lee'] spec.summary = 'hello world' spec.bins = ['hello'] spec.add_dependency 'mruby-print', :core => 'mruby- print' spec.add_dependency 'mruby-mtest', :mgem => 'mruby- mtest' spec.add_dependency 'mruby-yaml', :github => 'hone/mruby-yaml' end
79. core mrbgems ├── [4.0K] mruby-array-ext ├── [4.0K] mruby-bin-debugger ├── [4.0K] mruby-bin-mirb ├── [4.0K] mruby-bin-mrbc ├── [4.0K] mruby-bin-mruby ├── [4.0K] mruby-bin-mruby-config ├── [4.0K] mruby-bin-strip ├── [4.0K] mruby-compiler ├── [4.0K] mruby-enumerator
80. mrbgem.rake MRuby::Gem::Specification.new('hello') do |spec| spec.license = 'MIT' spec.authors = ['Terence Lee'] spec.summary = 'hello world' spec.bins = ['hello'] spec.add_dependency 'mruby-print', :core => 'mruby- print' spec.add_dependency 'mruby-mtest', :mgem => 'mruby- mtest' spec.add_dependency 'mruby-yaml', :github => 'hone/mruby-yaml' end
81. mgem list
82. mrbgem.rake MRuby::Gem::Specification.new('hello') do |spec| spec.license = 'MIT' spec.authors = ['Terence Lee'] spec.summary = 'hello world' spec.bins = ['hello'] spec.add_dependency 'mruby-print', :core => 'mruby- print' spec.add_dependency 'mruby-mtest', :mgem => 'mruby- mtest' spec.add_dependency 'mruby-yaml', :github => 'hone/mruby-yaml' end
83. build_config.rb MRuby::Build.new do |conf| toolchain :gcc conf.enable_bintest conf.enable_debug conf.enable_test gem_config(conf) end
84. build_config.rb def gem_config(conf) # be sure to include this gem conf.gem File.expand_path(File. dirname(__FILE__)) conf.gem :github => 'hone/mruby-yaml' end
85. Testing
86. mtest module MRubyCLI class TestUtil < MTest::Unit::TestCase def test_camelize assert_equal "GoodNightMoon", Util.camelize ("good_night_moon") assert_equal "FooBarBaz", Util.camelize("foo- bar-baz") end end end MTest::Unit.new.run
87. mtest (cont.) $ docker-compose run mtest >>> Test host <<< mrbtest - Embeddable Ruby Test .....S... # Running tests: .. Finished tests in 0.000305s, 6557.3770 tests/s, 26229.5082 assertions/s. 2 tests, 8 assertions, 0 failures, 0 errors, 0 skips
88. bintest require 'open3' require 'tmpdir' BIN_PATH = File.join(File.dirname(__FILE__), ".. /mruby/bin/hello") assert('setup') do output, status = Open3.capture2("#{BIN_PATH}") assert_true status.success?, "Process did not exit cleanly" assert_include output, "Hello World" end
89. bintest (cont.) $ docker-compose run bintest . Total: 1 OK: 1 KO: 0 Crash: 0 Time: 0.01 seconds
90. Gotchas
91. no stdlib
92. Can't leverage Rubygems
93. mrbgems that have native extensions need to support cross compiling
94. jruby-launcher
95. jruby/jruby -- bin/
96. jruby/jruby-launcher
97. jruby.cpp /* * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER. * * Copyright 1997-2008, 2010 Sun Microsystems, Inc. All rights reserved. * * The contents of this file are subject to the terms of either the GNU * General Public License Version 2
98. mjruby https://github.com/jkutner/mjruby
99. mjruby/test
100. mruby-cli & you
101. Young Community
102. mruby/mruby on github
104. Building a CLI App • download the mruby-cli binary • install Docker Toolbox • mruby-cli --setup calculator • add new functionality ◦ modify to build a calculator or just start with addition • docker-compose run compile • modify, recompile • tweet at me (@hone02)
105. Friday Hug!
106. #rubykaraoke
107. Let's build things in Ruby
108. Thank You @hone02 https://github.com/hone/mruby-cli