Class: OsCtl::Lib::OsProcess

Inherits:
Object
  • Object
show all
Defined in:
lib/libosctl/os_process.rb

Overview

Interface to system processes, reading information from `/proc`

Constant Summary collapse

TICS_PER_SECOND = 
Etc.sysconf(Etc::SC_CLK_TCK).to_i

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(pid) ⇒ OsProcess

Returns a new instance of OsProcess.

Parameters:

  • pid (Integer) 


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# File 'lib/libosctl/os_process.rb', line 76

def initialize(pid)
  @path = File.join('/proc', pid.to_s)
  @pid = pid
  @cache = {}
  @id_maps = {}

  volatile do
    parse_stat
    parse_status
  end
end

Instance Attribute Details

#egid ⇒ Integer (readonly)

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 41

def egid
  @egid
end

#euid ⇒ Integer (readonly)

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 35

def euid
  @euid
end

#name ⇒ String (readonly)

Returns:

  • (String) 


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# File 'lib/libosctl/os_process.rb', line 47

def name
  @name
end

#nice ⇒ Integer (readonly)

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 58

def nice
  @nice
end

#nspid ⇒ Array (readonly)

Returns:

  • (Array) 


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# File 'lib/libosctl/os_process.rb', line 29

def nspid
  @nspid
end

#num_threads ⇒ Integer (readonly)

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 61

def num_threads
  @num_threads
end

#path ⇒ Object (readonly, protected)

Returns the value of attribute path.



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# File 'lib/libosctl/os_process.rb', line 164

def path
  @path
end

#pgrp ⇒ Integer (readonly)

Process group ID

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 26

def pgrp
  @pgrp
end

#pid ⇒ Integer (readonly)

Process ID

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 18

def pid
  @pid
end

#ppid ⇒ Integer (readonly)

Parent process ID

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 22

def ppid
  @ppid
end

#rgid ⇒ Integer (readonly)

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 38

def rgid
  @rgid
end

#rss ⇒ Integer (readonly)

Resident set size

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 55

def rss
  @rss
end

#ruid ⇒ Integer (readonly)

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 32

def ruid
  @ruid
end

#start_time ⇒ Time (readonly)

Time when the process was started

Returns:

  • (Time) 


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# File 'lib/libosctl/os_process.rb', line 73

def start_time
  @start_time
end

#state ⇒ String (readonly)

Returns:

  • (String) 


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# File 'lib/libosctl/os_process.rb', line 44

def state
  @state
end

#sys_time ⇒ Integer (readonly)

Number of seconds this process was scheduled in kernel mode

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 69

def sys_time
  @sys_time
end

#user_time ⇒ Integer (readonly)

Number of seconds this process was scheduled in user mode

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 65

def user_time
  @user_time
end

#vmsize ⇒ Integer (readonly)

Virtual memory size

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 51

def vmsize
  @vmsize
end

Class Method Details

.system_start_time ⇒ Object 



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# File 'lib/libosctl/os_process.rb', line 8

def self.system_start_time
  unless @system_start_time
    @system_start_time = Time.now - File.read('/proc/uptime').strip.split.first.to_i
  end

  @system_start_time
end

Instance Method Details

#cache(key) ⇒ Object (protected) 



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# File 'lib/libosctl/os_process.rb', line 241

def cache(key)
  if @cache.has_key?(key)
    @cache[key]
  else
    @cache[key] = yield
  end
end

#cmdline ⇒ String

Read /proc/<pid>/cmdline

Returns:

  • (String) 


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# File 'lib/libosctl/os_process.rb', line 153

def cmdline
  volatile { File.read(File.join(path, 'cmdline')).gsub("\0", " ").strip }
end

#ct_egid ⇒ Integer?

Returns:

  • (Integer, nil) 


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# File 'lib/libosctl/os_process.rb', line 147

def ct_egid
  uns_host_to_ns('gid', egid)
end

#ct_euid ⇒ Integer?

Returns:

  • (Integer, nil) 


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# File 'lib/libosctl/os_process.rb', line 142

def ct_euid
  uns_host_to_ns('uid', euid)
end

#ct_id ⇒ Array?

Return container pool and id as a tuple or nil

Returns:

  • (Array, nil) 


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# File 'lib/libosctl/os_process.rb', line 106

def ct_id
  cache(:ct_id) do
    volatile do
      File.open(File.join(path, 'cgroup'), 'r') do |f|
        # It's not enough to check the first cgroup, it can happen that
        # the process remains only in some cgroups that belong to
        # the container, e.g. on an incorrect shutdown.
        f.each_line do |line|
          _id, _subsys, path = line.split(':')

          next if /^\/osctl\/pool\.([^\/]+)/ !~ path
          pool = $1

          next if /ct\.([^\/]+)\/user\-owned(\/|$)/ !~ path
          ctid = $1

          return [pool, ctid]
        end
      end

      nil
    end
  end
end

#ct_pid ⇒ Integer

Return PID as seen in the container's PID namespace

Returns:

  • (Integer) 


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# File 'lib/libosctl/os_process.rb', line 100

def ct_pid
  nspid[1]
end

#ct_rgid ⇒ Integer?

Returns:

  • (Integer, nil) 


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# File 'lib/libosctl/os_process.rb', line 137

def ct_rgid
  uns_host_to_ns('gid', rgid)
end

#ct_ruid ⇒ Integer?

Returns:

  • (Integer, nil) 


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# File 'lib/libosctl/os_process.rb', line 132

def ct_ruid
  uns_host_to_ns('uid', ruid)
end

#flush ⇒ Object

Flush cache and read fresh information from `/proc`



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# File 'lib/libosctl/os_process.rb', line 158

def flush
  @cache.clear
  @id_maps.clear
end

#grandparent ⇒ OsProcess

Returns:



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# File 'lib/libosctl/os_process.rb', line 94

def grandparent
  parent.parent
end

#id_map(type) ⇒ Object (protected) 



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# File 'lib/libosctl/os_process.rb', line 217

def id_map(type)
  @id_maps[type] ||= parse_id_map(type)
end

#parent ⇒ OsProcess

Returns:



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# File 'lib/libosctl/os_process.rb', line 89

def parent
  self.class.new(ppid)
end

#parse_id_map(type) ⇒ Object (protected) 



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# File 'lib/libosctl/os_process.rb', line 221

def parse_id_map(type)
  volatile do
    id_map = OsCtl::Lib::IdMap.new

    File.open(File.join(path, "#{type}_map"), 'r') do |f|
      f.each_line do |line|
        id_map.add_from_string(line, separator: ' ')
      end
    end

    id_map
  end
end

#parse_stat ⇒ Object (protected) 



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# File 'lib/libosctl/os_process.rb', line 166

def parse_stat
  File.open(File.join(path, 'stat'), 'r') do |f|
    line = f.readline
    fields = line[line.rindex(')') + 1..-1].split

    # The third field in /proc/<pid>/stat (State) is the first in here, i.e.
    # substract 3 from field index documented in man proc to get
    # the appropriate field
    @state = fields[0]
    @ppid = fields[1].to_i
    @pgrp = fields[2].to_i
    @user_time = fields[11].to_i / TICS_PER_SECOND
    @sys_time = fields[12].to_i / TICS_PER_SECOND
    @nice = fields[16].to_i
    @num_threads = fields[17].to_i
    @start_time = self.class.system_start_time + (fields[19].to_i / TICS_PER_SECOND)
    @vmsize = fields[20].to_i
    @rss = fields[21].to_i
  end
end

#parse_status ⇒ Object (protected) 



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# File 'lib/libosctl/os_process.rb', line 187

def parse_status
  File.open(File.join(path, 'status'), 'r') do |f|
    f.each_line do |line|
      parts = line.split(':')
      next if parts.count != 2

      k = parts[0].strip
      v = parts[1].strip

      case k
      when 'NSpid'
        @nspid = v.split.map(&:to_i)

      when 'Uid'
        @ruid, @euid, @svuid, @fsuid = v.split.map(&:to_i)

      when 'Gid'
        @rgid, @egid, @svgid, @fsgid = v.split.map(&:to_i)

      when 'Name'
        @name = v
      end
    end
  end
end

#uns_host_to_ns(type, host_id) ⇒ Object (protected) 



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# File 'lib/libosctl/os_process.rb', line 213

def uns_host_to_ns(type, host_id)
  id_map(type).host_to_ns(host_id)
end

#volatile ⇒ Object (protected) 



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# File 'lib/libosctl/os_process.rb', line 235

def volatile
  yield
rescue Errno::ENOENT
  raise Exceptions::OsProcessNotFound, pid
end