Crystal in Operation

サーバ管理業務に便利なCrystal言語の機能紹介。

Transcript

1. Crystal
   in
   Operation
   Crystal
   
   2018/07/18 Crystal.tokyo #7
   

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2. 61:+
   • ʕ·ᴥ·ʔAKJ )C
   @arcage arcage
   • =A37.8(/>D &$"
   • .80!'2,95*=A
   ?
   • B/0
   • ;/ &$"
   • &4
   
   • 6@- %4<#'
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3. :6*!.
   maillog
   )$#
   SMTP AUTH;/(
   IP "
   %8
   9&0.
   -
   +,"
   '
   /)51
   23
   10742"
   1$43"
   24$44"
   2018/07/18 Crystal.tokyo #7
   

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4. 
   
   
   
   https://crystal-lang.org/api/
   2018/07/18 Crystal.tokyo #7
   

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5. UTF-8
   
   
   2018/07/18 Crystal.tokyo #7
   

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6. IO#set_encoding
   #
   • #set_encoding
   • encoding: ICONV.-"
   • invalid: :skip or nil
   &)$UTF-8,
   • ' /+
   File.open("./data.txt") do |file|
   # Shift_JIS*0%
   # (!0
   file.set_ecoding("Shift_JIS", :skip)
   end
   # File.open
   #
   File.open("./data.txt", "w"
   encoding: "Shift_JIS",
   invalid: :skip)
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7. 
   
   
   2018/07/18 Crystal.tokyo #7
   

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8. File::Info#modification_time
   
   &
   0.24File::Stat
   • %
   • #ino #?
   • #mtime → #modification_time
   • #atime#utime #?
   f_info = File.info("./README.md")
   f_info.modification_time
   #=> 2018-02-02 05:11:53.379574681 UTC
   f_info.permissions
   #=> rw-r--r-- (0o644)
   f_info.size
   #=> 11325_u64
   # !"(inode$)
   f_info.same_file?(other_f_info)
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9. gz
   2018/07/18 Crystal.tokyo #7
   

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10. class Zlib::Reader
    gz
    •
    •
    
    Zlib::Reader IO
    •
    require "zlib"
    File.open("./maillog.gz") do |file|
    Zlib::Reader.open(file) do |gz|
    gz.each_line do |line|
    # ...
    end
    end
    end
    2018/07/18 Crystal.tokyo #7
    

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11. zip
    2018/07/18 Crystal.tokyo #7
    

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12. class Zip::Reader
    zip
    •
    • !
    Zip::Reader::Entry
    • Zip /
    • #io
    
    require "zip"
    Zip::Reader.open("./logs.zip") do |zip|
    zip.each_entry do |entry|
    entry.io.each_line do |line|
    # ...
    end
    end
    end
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13. 
    
    2018/07/18 Crystal.tokyo #7
    

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14. method system
    
    • 0
    true
    • 0 false
    system("which", ["cc"])
    #=> true
    #
    
    system("whic", ["cc"])
    #=> false
    # (Process::Status)
    $?.exit_code
    #=> 32512
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15. method ` ←
    
    •
    
    cc_path = `which cc`
    #=> "/usr/bin/cc\n"
    #
    
    cc_path = `whic cc`
    #=> ""
    #
    $?.exit_code
    #=> 32512
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16. class Process
    
    
    •
    
    • #wait
    • STDIN/OUT/ERR
    prc = Process.new("which", ["cc"])
    exit_status = prc.wait
    exit_status.exit_code
    #=> 0
    String.build { |io|
    Process.new("which", ["cc"]
    output: io).wait
    }
    #=> "/usr/bin/cc\n"
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17. 
    ID
    
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18. class Process
    
    • ID
    •
    
    • CPU
    …
    
    •
    
    • kill
    Process.pid
    #=> 9651
    Process.executable_path
    #=> "/home/user/bin/exec_file"
    Process.times
    #=> Process::Tms(@utime=0.0, @stime=0.0,
    @cutime=0.0, @cstime=0.0)
    Process.find_executable("cc")
    #=> "/usr/bin/cc"
    Process.kill(6523)
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19. UNIX
    
    
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20. enum Signal
    $!
    !
    • #trap do ... end
    • #reset
    Signal::INT.trap do
    # Ctrl+C
    "
    end
    Signal::HUP.trap do
    # !#
    end
    #
    Signal::INT.reset
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21. 
    
    
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22. module System
    CPU Sytem.hostname
    #=> "myhost.example.org"
    Sytem.cpu_count
    #=> 8_u64
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23. 97-I3F
    
    
    • 8.BG#$@
    • )*6(;&:5 Ruby 90D → Crystal 25D
    • =2H%'!%8.4
    • crystal run trial & error +C
    • 0EA1C?
    ,
    • "& %-I/
    2018/07/18 Crystal.tokyo #7
    

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24. 
    
    
    
    
    ……
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25. 
    
    
    https://guthub.com/arcage/***
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26. 
    
    crystal-logreader
    • !
    •
    tail -F
    require "logreader"
    log = LogReader.new("/var/log/maillog")
    log.each do |line|
    #...
    end
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27. 
    ip2country
    •
    • en/fr/es/de/ja/zh/ko
    ! /
    RIR delegations
    umpirsky/country-list
    require "ip2country"
    ip2c = IP2Country.new
    ip2c.lookup("8.8.8.8")
    #=> "United Status"
    ip2c.lookup("8.8.8.8", "ja")
    #=> "
    "
    ip2c = IP2Country.new("ja")
    ip2c.lookup("8.8.8.8")
    #=> "
    "
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28. %(
    
    crystal-email
    • UTF-8#
    • $&
    • HTML
    • AUTH PLAIN/LOGIN #
    • STARTTLS #
    • 'concurrent"
    Gmail
    
    • Thanks @sdogruyol!
    require "email"
    EMail.send("smtp.example.org") do
    from "you@example.org"
    to "other@example.org"
    subject ")!"
    message """
    attach "photo.jpg"
    end
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29. 
    crystal-patlite
    • PATLITE
    • PHN
    
    //
    //
    require "patlite"
    ip = "192.169.100.100"
    port = 10000
    plite = Patlite::PHN.new(ip, port)
    plite.set do
    green_on
    end
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30. 8
    #
    29
    -
    +," (!
    /*51
    10642"
    1%43"
    24%44"
    maillog *%$
    SMTP AUTH :/)
    IP" &7
    9'0.
    23
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31. 
    
    
    
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