module Unicorn::Util
Public Class Methods
reopen_logs()
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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.
# File lib/unicorn/util.rb, line 33 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