From e225cc96dbc081c457c2e5ad174988e49d062760 Mon Sep 17 00:00:00 2001
From: Denis Knauf <d.knauf@nfotex.com>
Date: Fri, 13 Oct 2023 22:50:09 +0200
Subject: [PATCH] renamed to lxc-exporter. os-release, apt update / upgradable.

---
 config.ru                            |   4 +-
 pvect-exporter.rb => lxc-exporter.rb | 203 +++++++++++++++++++--------
 2 files changed, 146 insertions(+), 61 deletions(-)
 rename pvect-exporter.rb => lxc-exporter.rb (53%)
 mode change 100644 => 100755

diff --git a/config.ru b/config.ru
index 7795fe1..d7e04c2 100644
--- a/config.ru
+++ b/config.ru
@@ -1,12 +1,12 @@
 require 'rack'
-require_relative 'pvect-exporter'
+require_relative 'lxc-exporter'
 require 'prometheus/client/formats/text'
 
 run lambda {|env|
   req = Rack::Request.new env
   case req.path
   when "/metrics"
-    collector = PveCtCollector.new
+    collector = LxcCollector.new
     [200, {"Content-Type" => "text/plain"}, [Prometheus::Client::Formats::Text.marshal( collector.collect)]]
   else
     [404, {"Content-Type" => "text/plain"}, ["Not found\nYou want to try /metrics?\n"]]
diff --git a/pvect-exporter.rb b/lxc-exporter.rb
old mode 100644
new mode 100755
similarity index 53%
rename from pvect-exporter.rb
rename to lxc-exporter.rb
index 4ae292a..f2608b9
--- a/pvect-exporter.rb
+++ b/lxc-exporter.rb
@@ -26,7 +26,6 @@ end
 class File
   module Statfs
     Magics = {}
-#=begin
     Line = <<~EOF
       ADFS	0xadf5
       AFFS	0xadff
@@ -121,7 +120,6 @@ class File
         end
       Magics[v] = n.downcase.to_sym
     end
-#=end
 
     extend Fiddle::Importer
     dlload Fiddle.dlopen( nil)
@@ -164,17 +162,12 @@ class File
 end
 
 class NS
-  #extend FFI::Library
-  #ffi_lib 'c'
-  #attach_function :setns_without_exception_handling, :setns, %i[int int], :int
   extend Fiddle::Importer
   dlload Fiddle.dlopen( nil)
   SetNS_Function = Fiddle::Function.new handler['setns'], [Fiddle::TYPE_VOIDP, Fiddle::TYPE_VOIDP], Fiddle::TYPE_INT
 
   class <<self
     def setns fd, t
-      #r = setns_without_exception_handling fd.to_i, t.to_i
-      #SystemCallError.new "setns(#{fd.to_i})", FFI::LastError.error  if -1 == r
       r = SetNS_Function.call fd.to_i, t.to_i
       SystemCallError.new "setns(#{fd.to_i})", Fiddle.last_error  if -1 == r
       r
@@ -247,81 +240,173 @@ class MountInfo
   end
 end
 
-=begin
-LxcStartExe = Pathname.new "/usr/bin/lxc-start"
-def get_running_ct_pids &block
-  return to_enum( __method__)  unless block_given?
+class OsRelease
+  Path = Pathname.new '/etc/os-release'
+  class <<self
+    def parse txt
+      r =
+        txt.each_line.
+        map do |l|
+          k, v =
+            *case l.chomp
+            when /^([^=]+)="(.*)"$/ then [$1, $2]
+            when /^([^=]+)=(.*)$/ then [$1,$2]
+            else next
+            end
+          [ k.downcase.to_sym, v.sub( /^"/, '').sub( /"$/, '') ]
+        end.
+        compact.
+        to_h
+      new r
+    end
 
-  cts = []
-  Pathname.new( "/proc").each_child do |fn|
-    next  if /\D/ =~ fn.basename.to_s
-    exepath = fn + 'exe'
-    next  unless exepath.exist? and LxcStartExe == exepath.readlink
-    pid = fn.basename.to_s.to_i
-    cts.push pid
+    def read()  parse Path.read  if Path.exist?  end
   end
 
-  Pathname.new( "/proc").each_child do |fn|
-    next  if /\D/ =~ fn.basename.to_s
-    statuspath = fn + 'status'
-    ppid = statuspath.read.match( /^PPid:\s+(\d+)$/)[1].to_i
-    next  unless cts.include? ppid
-    yield fn.basename.to_s.to_i
+  def initialize( h)  @h = h.freeze  end
+  def to_h()  @h.dup  end
+  def []( n)  @h[n]  end
+
+  def missing_method n, *a
+    if a.empty? and @h.has_key?( n)
+      @h[n]
+    else
+      super n, *a
+    end
   end
 end
-pids = get_running_ct_pids
-=end
 
-class PveCtCollector
-  def fetch
-    LXC.list_containers.map {|n|LXC::Container.new n}.select( &:running?).each do |ct|
-      pid = ct.init_pid
-      mis = MountInfo.of pid
-      NS.change pid, :pid, :mnt do
-        mis.each do |mi|
-          next if %w[devpts devtmpfs fuse.lxcfs].include? mi.type
-          statfs = File::Statfs.new mi.mp
-          yield ct, mi.mp, statfs
-        end
-      end
+class LxcCollector
+  def statfs ct, mis
+    mis.each do |mi|
+      next if %w[devpts devtmpfs fuse.lxcfs].include? mi.type
+      statfs = File::Statfs.new mi.mp
+      yield ct, mi.mp, statfs
     end
   end
 
   def initialize registry = nil
     @prometheus ||= Prometheus::Client::Registry.new
-    @info   = Prometheus::Client::Gauge.new :pvect_filesystem_info,            labels: %i[id mountpoint name fstype], docstring: 'CT Info'
-    @totalb = Prometheus::Client::Gauge.new :pvect_filesystem_total_bytes,     labels: %i[id mountpoint], docstring: 'Total bytes in filesystem'
-    @freeb  = Prometheus::Client::Gauge.new :pvect_filesystem_free_bytes,      labels: %i[id mountpoint], docstring: 'Free bytes in filesystem'
-    @availb = Prometheus::Client::Gauge.new :pvect_filesystem_available_bytes, labels: %i[id mountpoint], docstring: 'Free bytes available to unprivileged user'
-    @totalf = Prometheus::Client::Gauge.new :pvect_filesystem_total_files,     labels: %i[id mountpoint], docstring: 'Total files in filesystem'
-    @freef  = Prometheus::Client::Gauge.new :pvect_filesystem_free_files,      labels: %i[id mountpoint], docstring: 'Free files in filesystem'
-    [@info, @totalb, @freeb, @availb, @totalf, @freef].each {|g| @prometheus.register g }
+    @info   = Prometheus::Client::Gauge.new :lxc_filesystem_info,           
+      labels: %i[id mountpoint name fstype], docstring: 'CT Info'
+    @totalb = Prometheus::Client::Gauge.new :lxc_filesystem_total_bytes,    
+      labels: %i[id mountpoint], docstring: 'Total bytes in filesystem'
+    @freeb  = Prometheus::Client::Gauge.new :lxc_filesystem_free_bytes,     
+      labels: %i[id mountpoint], docstring: 'Free bytes in filesystem'
+    @availb = Prometheus::Client::Gauge.new :lxc_filesystem_available_bytes,
+      labels: %i[id mountpoint], docstring: 'Free bytes available to unprivileged user'
+    @totalf = Prometheus::Client::Gauge.new :lxc_filesystem_total_files,    
+      labels: %i[id mountpoint], docstring: 'Total files in filesystem'
+    @freef  = Prometheus::Client::Gauge.new :lxc_filesystem_free_files,     
+      labels: %i[id mountpoint], docstring: 'Free files in filesystem'
+    @os_release = Prometheus::Client::Gauge.new :lxc_os_release_info,       
+      labels: %i[id name os_id os_name os_pretty_name os_version_codename],
+      docstring: 'OS release info'
+    @os_version = Prometheus::Client::Gauge.new :lxc_os_version_id,
+      labels: %i[id], docstring: 'OS release (distribution) version'
+    @pkgs_upgradable = Prometheus::Client::Gauge.new :lxc_packages_upgradable,
+      labels: %i[id], docstring: 'Count of upgradable packages'
+    @pkgs_last_update = Prometheus::Client::Gauge.new :lxc_packages_last_update,
+      labels: %i[id], docstring: 'Last successfull source update'
+    [
+      @info, @totalb, @freeb, @availb, @totalf, @freef,
+      @os_release, @os_version,
+      @pkgs_upgradable, @pkgs_last_update
+    ].each {|g| @prometheus.register g }
+  end
+
+  def running_containers &exe
+    return to_enum __method__  unless block_given?
+    LXC.
+      list_containers.
+      map {|n| LXC::Container.new n }.
+      select( &:running?).
+      each &exe
+  end
+
+  AptLastUpdateFile = Pathname.new '/var/cache/apt/pkgcache.bin'
+
+  def forked wr
+    running_containers do |ct|
+      pid = ct.init_pid
+      mis = MountInfo.of pid
+      NS.change pid, :pid, :mnt do
+        name = ct.config_item( 'lxc.uts.name')
+        statfs ct, mis do |ct, mp, st|
+          next  unless st.fstypename and 0 < st.blocks
+          st = st.to_h.merge mp: mp, id: ct.name, name: name
+          wr.puts [:mountpoint, st].to_json
+        end
+        osr = OsRelease.read
+        if osr
+          wr.puts [:os_release, {
+            id: ct.name, name: name,
+            os_id:               osr[:id],
+            os_name:             osr[:name],
+            os_pretty_name:      osr[:pretty_name],
+            os_version_id:       osr[:version_id].to_i,
+            os_version_codename: osr[:version_codename]
+          }].to_json
+          case osr[:id].to_sym
+          when :debian
+            upgradable = nil
+            pid = 
+              IO.popen %w[apt list --upgradable], err: "/dev/null" do |apt|
+                upgradable = apt.readlines.length - 1
+              end
+            wr.puts [:pkgs, {
+              id: ct.name, name: name, upgradable: upgradable,
+              last_update: AptLastUpdateFile.stat.mtime.to_f,
+            }].to_json
+          end
+        end
+      end
+    end
+    wr.close
+    exit 0
   end
 
   def collect
     rd, wr = IO.pipe
     pid = fork do
       rd.close
-      fetch do |ct, mp, st|
-        next  unless st.fstypename and 0 < st.blocks
-        wr.puts st.to_h.merge( mp: mp, id: ct.name, name: ct.config_item( 'lxc.uts.name')).to_json
-      end
-      wr.close
-      exit 0
+      forked wr
     end
     wr.close
     rd.each_line do |l|
-      st = OpenStruct.new JSON.parse( l)
-      labels = {id: st.id, mountpoint: st.mp}
-      @info.set 1, labels: labels.merge( name: st.name, fstype: st.fstypename)
-      @totalb.set st.bsize*st.blocks, labels: labels
-      @freeb.set  st.bsize*st.bfree,  labels: labels
-      @availb.set st.bsize*st.bavail, labels: labels
-      @totalf.set st.files, labels: labels
-      @freef.set  st.ffree, labels: labels
+      l = JSON.parse l, symbolize_names: true
+      case l[0].to_sym
+      when :mountpoint
+        st = OpenStruct.new l[1]
+        labels = {id: st.id, mountpoint: st.mp}
+        @info.set 1, labels: labels.merge( name: st.name, fstype: st.fstypename)
+        @totalb.set st.bsize*st.blocks, labels: labels
+        @freeb.set  st.bsize*st.bfree,  labels: labels
+        @availb.set st.bsize*st.bavail, labels: labels
+        @totalf.set st.files, labels: labels
+        @freef.set  st.ffree, labels: labels
+      when :os_release
+        osr = OpenStruct.new l[1]
+        @os_release.set 1, labels: { id: osr.id, name: osr.name,
+          os_id: osr.os_id,
+          os_name: osr.os_name,
+          os_pretty_name: osr.os_pretty_name,
+          os_version_codename: osr.os_version_codename
+        }
+        @os_version.set osr.os_version_id, labels: {id: osr.id}
+      when :pkgs
+        as = OpenStruct.new l[1]
+        @pkgs_last_update.set as.last_update, labels: { id: as.id }
+        @pkgs_upgradable.set  as.upgradable, labels: { id: as.id }
+      end
     end
     rd.close
     Process.wait pid
     @prometheus
   end
 end
+
+if Pathname.new( __FILE__).expand_path == Pathname.new( $0).expand_path
+  require 'prometheus/client/formats/text'
+  puts Prometheus::Client::Formats::Text.marshal( LxcCollector.new.collect)
+end