cbor (CBORIO) for comunication between processes.

Gemfile

@@ -3,3 +3,4 @@ gem 'ruby-lxc', git: 'https://git.denkn.at/deac/ruby-lxc'
 gem 'prometheus-client'
 gem 'puma'
 gem 'rack'
+gem 'cbor'

lib/cborio.rb

@@ -0,0 +1,54 @@
+require 'cbor'
+
+class CBORIO
+  include Enumerable
+  def orig_io() @io end
+  def unpacker() @un end
+  def close() @io.close end
+  def write( obj) @io.write CBOR.pack( obj) end
+  def sync() @io.sync end
+  def sync( v) @io.sync = v end
+  def self.pipe() IO.pipe.map &self.method(:new) end
+  def self.popen &exe
+    rd, wr = self.pipe
+    pid =
+      fork do
+        rd.close
+        yield wr
+        exit 0
+      end
+    wr.close
+    [pid, rd]
+  end
+
+  def initialize io
+    @io, @un = io, CBOR::Unpacker.new
+    @io.sync = true
+  end
+
+  def self.open io, &exe
+    if block_given?
+      s = self.new io
+      begin yield s
+      ensure s.close
+      end
+    else self.new io
+    end
+  end
+
+  def read
+    return @un.read  rescue EOFError
+    loop do
+      @un.feed @io.readpartial( 1024)
+      return @un.read  rescue EOFError
+    end
+  end
+
+  def each &exe
+    return to_enum __method__  unless block_given?
+    loop { yield read }
+    self
+  rescue EOFError
+    self
+  end
+end

lib/lxc_collector.rb

@@ -1,35 +1,20 @@
 #!/usr/bin/env ruby
 
 require 'pathname'
-require 'json'
 require 'prometheus/client'
 require 'lxc'
 
 require_relative 'ns'
 require_relative 'file-statfs'
+require_relative 'cborio'
+require_relative 'lxc_extend'
 require_relative 'lxc-exporter/os_release'
 require_relative 'lxc-exporter/mount_info'
-require_relative 'lxc_extend'
-
-=begin
-class LXC::CT
-  def initialize name
-    extend Fiddle::Importer
-    dlload Fiddle.dlopen( nil)
-
-    extern 'lxc_container *lxc_container_new( const char* name, const char* config_path)'
-
-    def initialize name, config = nil
-      lxc_container_new name, config
-    end
-  end
-end
-=end
 
 class LxcCollector
   include Prometheus::Client
 
-  CTStates = { aborting: -1, stopped: 0, starting: 1, stopping: 2, running: 3 }
+  CTStates = { aborting: -1, stopped: 0, starting: 0.75, stopping: 0.25, running: 1 }
 
   def statfs ct, mis
     mis.each do |mi|
@@ -81,32 +66,38 @@ class LxcCollector
       mis = MountInfo.of pid
       NS.change pid, :pid, :mnt do
         name = ct.config_item( 'lxc.uts.name')
+
+        # Filesystems
         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
+          wr.write [:mountpoint, st]
         end
+
+        # OS / Distribution
         osr = OsRelease.read
         if osr
-          wr.puts [:os_release, {
+          wr.write [: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
+          # Special things for Debian(-based) distributions
           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, {
+            wr.write [:pkgs, {
               id: ct.name, name: name, upgradable: upgradable,
               last_update: AptLastUpdateFile.stat.mtime.to_f,
-            }].to_json
+            }]
           end
         end
       end
@@ -116,19 +107,13 @@ class LxcCollector
   end
 
   def collect
-    rd, wr = IO.pipe
-    pid = fork do
-      rd.close
-      forked wr
-    end
-    wr.close
     LXC.containers do |ct|
       labels = { id: ct.name, name: ct.config_item( 'lxc.uts.name') }
       @up.set ct.running? ? 1 : 0, labels: labels
       @state.set CTStates[ct.state], labels: labels
     end
-    rd.each_line do |l|
+    pid, rd = CBORIO.popen( &method( :forked))
-      l = JSON.parse l, symbolize_names: true
+    rd.each do |l|
       case l[0].to_sym
 
       when :mountpoint
@@ -155,7 +140,7 @@ class LxcCollector
       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 }
+        @pkgs_upgradable.set  as.upgradable,  labels: { id: as.id }
       end
     end
     rd.close