Module: Unicorn::Util

Defined in:
lib/unicorn/util.rb

Overview

:nodoc:

Class Method Summary collapse

Class Method Details

.chown_logs(uid, gid) ⇒ Object


18
19
20
21
22
# File 'lib/unicorn/util.rb', line 18

def self.chown_logs(uid, gid)
  ObjectSpace.each_object(File) do |fp|
    fp.chown(uid, gid) if is_log?(fp)
  end
end

.is_log?(fp) ⇒ Boolean

:stopdoc:

Returns:

  • (Boolean)

7
8
9
10
11
12
13
14
15
16
# File 'lib/unicorn/util.rb', line 7

def self.is_log?(fp)
  append_flags = File::WRONLY | File::APPEND

  ! fp.closed? &&
    fp.stat.file? &&
    fp.sync &&
    (fp.fcntl(Fcntl::F_GETFL) & append_flags) == append_flags
  rescue IOError, Errno::EBADF
    false
end

.reopen_logsObject

This reopens ALL logfiles in the process that have been rotated using logrotate(8) (without copytruncate) or similar tools. A File object is considered for reopening if it is:

1) opened with the O_APPEND and O_WRONLY flags
2) the current open file handle does not match its original open path
3) unbuffered (as far as userspace buffering goes, not O_SYNC)

Returns the number of files reopened

In Unicorn 3.5.x and earlier, files must be opened with an absolute path to be considered a log file.


35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
# File 'lib/unicorn/util.rb', line 35

def self.reopen_logs
  to_reopen = []
  nr = 0
  ObjectSpace.each_object(File) { |fp| is_log?(fp) and to_reopen << fp }

  to_reopen.each do |fp|
    orig_st = begin
      fp.stat
    rescue IOError, Errno::EBADF # race
      next
    end

    begin
      b = File.stat(fp.path)
      next if orig_st.ino == b.ino && orig_st.dev == b.dev
    rescue Errno::ENOENT
    end

    begin
      # stdin, stdout, stderr are special.  The following dance should
      # guarantee there is no window where `fp' is unwritable in MRI
      # (or any correct Ruby implementation).
      #
      # Fwiw, GVL has zero bearing here.  This is tricky because of
      # the unavoidable existence of stdio FILE * pointers for
      # std{in,out,err} in all programs which may use the standard C library
      if fp.fileno <= 2
        # We do not want to hit fclose(3)->dup(2) window for std{in,out,err}
        # MRI will use freopen(3) here internally on std{in,out,err}
        fp.reopen(fp.path, "a")
      else
        # We should not need this workaround, Ruby can be fixed:
        #    http://bugs.ruby-lang.org/issues/9036
        # MRI will not call call fclose(3) or freopen(3) here
        # since there's no associated std{in,out,err} FILE * pointer
        # This should atomically use dup3(2) (or dup2(2)) syscall
        File.open(fp.path, "a") { |tmpfp| fp.reopen(tmpfp) }
      end

      fp.sync = true
      fp.flush # IO#sync=true may not implicitly flush
      new_st = fp.stat

      # this should only happen in the master:
      if orig_st.uid != new_st.uid || orig_st.gid != new_st.gid
        fp.chown(orig_st.uid, orig_st.gid)
      end

      nr += 1
    rescue IOError, Errno::EBADF
      # not much we can do...
    end
  end
  nr
end