ascii.io - no non-sense asciicasting for serious hackers

My RubyShift 2012 conf talk title "ascii.io - no nonsense asciicasting for serious hackers".

Transcript

1. ascii.io NO NON-SENSE ASCIICASTING FOR SERIOUS HACKERS
2. MARCIN KULIK
3. I WORK AT
4. I CURRENTLY WORK ON: kanbanery.com
5. I SHARE AT GITHUB & TWITTER AS SICKILL
6. YOU MAY KNOW ME FROM: racksh, ascii.io, git-dude, vim-pasta, bitpocket, coloration, stderred... All of them available at https://github.com/sickill/
7. Quick history lesson
9. VT100 RELEASED IN 1978 FOUNDATION FOR TERMINALS WE USE
10. Ruby developer workflow
11. rake git vim rails {generate, console, ...}
12. Screencasts
13. "Recording the work in your terminal with screen capture software and serving it as a video is like recording your text reply as an .mp3 file and sending it via email" - Me.
14. typescript
15. /usr/bin/script
16. # man script NAME script — make typescript of terminal session DESCRIPTION script makes a typescript of everything printed on your terminal. It is useful for students who need a hardcopy record of an interactive session as proof of an assignment, as the typescript file can be printed out later with lpr(1).
17. RECORDING: $ script -t session1 2>session1.time
18. /usr/bin/scriptreplay
19. # man scriptreplay NAME scriptreplay - play back typescripts, using timing information DESCRIPTION This program replays a typescript, using timing information to ensure that output happens at the same speed as it originally appeared when the script was recorded.
20. REPLAYING: $ scriptreplay foo.time foo
21. Sharing
22. Requirements for sharing Simplest possible recording in the terminal Simplest possible replay in the browser
23. ascii.io was born
24. "ASCII.IO is the simplest way to record your terminal and share the recordings with your fellow geeks. Simply record and upload your terminal session with single command, and ASCII.IO will play it back in your browser."
25. Quick demo
26. 4 building blocks of ascii.io
27. terminal recorder http://ascii.io/ site with an API in-browser player background job for thumbnails
28. The recorder
29. Recording is covered /USR/BIN/SCRIPT
30. Well, on Linux yes
31. On OSX /usr/bin/script is crippled
32. A little bit of Yak Shaving
33. script.c 433 LINES OF C CODE CREATES PTY - PSEUDO-TERMINAL
34. How script.c works
35. it has its STDIN and STDOUT connected to the terminal app it forks and execs shell in child process it gets file descriptors for spawned process' STDIN and STDOUT it proxies STDIN and STDOUT and saves STDOUT to a file
36. Requirements for the recorder
37. works on both Linux and OSX has minimum dependencies has simplest possible installation is targetted not at Rubyists only
38. script.rb?
39. script.rb pros Ruby! Ruby has PTY module in stdlib
40. script.rb cons WELL... RUBY
41. Requires ruby installed
42. PTY module differs between 1.8 / 1.9
43. I don't control user environment DOES USER HAVE 1.8 OR 1.9? NO RUBY AT ALL?
44. script.py?
45. script.py pros Python is preinstalled on Linux/OSX Python has pty module in stdlib
46. pty module haven't changed in years
47. LIKE IN 10+ YEARS
48. script.py then! ~400 LOC no dependencies records STDOUT + timing saves environment info uploads
49. "It was just safer to use Python here" - Me.
50. Term recording ✔
51. The site
52. Requirements for the site Replaying asciicast Browsing through asciicasts Basic (optional) profile
53. Next slide will be boring...
54. I built the site in Rails
55. The player
56. Flash?
57. "That Steve guy famously said it's proprietary and closed, too." http://isflashdeadyet.com/
58. Java applet?
60. Ruby?
61. Javascript?
62. Javascript then! TECHNICALLY COFFEESCRIPT :)
63. HTML5 based VT100/102 implementation
64. Multiple renderers: <pre> and <canvas> Fast Tested with Jasmine
65. Renderers 2 AVAILABLE NOW: <pre> based, with "copy & paste" <canvas> based, faster, no "copy & paste" TODO: WebGL based one
66. Fast & responsive THANKS TO HTML5 requestAnimationFrame WebWorker
67. Soon to be extracted from ascii.io
68. Replaying ✔
69. Thumbnails
71. Requirements for thumbnail generation
72. happens in background job after uploading takes terminal snapshot at 10 sec mark thumbnail just text
73. ffmpeg? WELL, NO. IT'S NOT VIDEO FILE.
74. Xvfb + xterm + scriptreplay? WELL, NO. SCRIPTREPLAY DOESN'T DO SNAPSHOTS.
75. Xvfb + xterm + scriptreplay + screenshot? WELL, NO. I WANT TEXT.
76. scriptreplay won't do then...
77. nodejs maybe?
78. Maybe, via: standalone nodejs bin therubyracer gem
79. Something told me to man tmux
80. tmux?
81. "tmux is a terminal multiplexer: it enables a number of terminals to be created, accessed, and controlled from a single screen. tmux may be detached from a screen and continue running in the background, then later reattached."
82. How tmux fits here???
83. $ man tmux capture-pane [-b buffer-index] [-E end-line] [-S start-line] [-t target-pane] Capture the contents of a pane to the specified buffer, or a new buffer if none is specified.
84. $ man tmux save-buffer [-a] [-b buffer-index] path Save the contents of the specified paste buffer to path. The -a option appends to rather than overwriting the file.
85. scriptreplay will do then!
86. Plan
87. BACKGROUND JOB THAT: creates new, detached tmux session runs `scriptreplay` in it waits for 10 sec runs `tmux capture-pane` runs `tmux save-buffer`
88. // app/jobs/capture_job.rb class CaptureJob def self.perform(...) system "tmux new -s $SESS_ID -d -x $X -y $Y 'scriptreplay ....'" sleep 10 system "tmux capture-pane -t $SESS_ID" system "tmux save-buffer -" system "tmux kill-session -t $SESS_ID &>/dev/null" end end
89. Don't go this way USE BASH!
90. // script/capture.sh #!/bin/bash tmux new -s $SESS_ID -d -x $COLS -y $LINES "scriptreplay ...." sleep 10 tmux capture-pane -t $SESS_ID tmux save-buffer - tmux kill-session -t $SESS_ID &>/dev/null
91. Thumbnails ✔
92. It's open-source
93. SOURCE ON FACEBOOK, ERRR.. ON GITHUB Web app: github.com/sickill/ascii.io Recorder: github.com/sickill/ascii.io-cli CONTRIBUTE!
94. Run your own (private) instance
95. That's easy create S3 bucket for files easily deploy to Heroku export ASCII_IO_API_URL=http://your- app.herokuapp.com in .bashrc
96. Example use cases
97. Tutorials Rails blog app in 15 minutes? ;) Vim git shell tricks
98. Bug reporting app starts leaking memory app starts eating CPU
99. Auto-recording of shell sessions
100. # end of .bashrc if [ -z "$RECORDING" ]; then export RECORDING=1 ASCII_IO_API_URL=http://localhost:3000 exec asciiio -y fi Thx @roy & @_solnic_ !
101. Summary
102. Use Ruby where it feels natural
103. You need to learn other languages & technologies
104. Believe in what you do!
105. Thanks! QUESTIONS PLEASE!