Class: OpenVZ::Container

Inherits:
Object show all
Defined in:
lib/openvz/container.rb

Overview

OpenVZ::Container

Examples:

Sample Usage

c = Container.new("999")
c.start
c.stop
c.restart
c.mount
c.umount
c.destroy

Configration Access

c = Container.new("999")
puts c.config.privvmpages
c.config.privvmpages = "123:123"

Container Creation

c = Container.new("999")
c.create( :ostemplate => "debian-6.0-bootstrap", :config => "vps.unlimited" )
c.debootstrap( :dist => "squeeze", :mirror => "http://ftp.at.debian.org" )
c.cp_into(:src => "/etc/resolv.conf", :dest => "/etc/resolv.conf")
c.start
c.command("hostname -f")

Author:

  • Stefan Schlesinger

Defined Under Namespace

Classes: Config, StatemachineError

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(ctid = false) ⇒ Container

Returns a new instance of Container.



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# File 'lib/openvz/container.rb', line 37

def initialize(ctid=false)
    @ctid       = ctid
    @vzctl      = "/usr/sbin/vzctl"
    @configfile = "/etc/vz/conf/#{ctid}.conf"

    @config     = Config.new(load_config_file)
    @config.add_observer(self)
end

Instance Attribute Details

#config ⇒ Object

Returns the value of attribute config.



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# File 'lib/openvz/container.rb', line 30

def config
  @config
end

#ctid ⇒ Object (readonly)

Returns the value of attribute ctid.



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# File 'lib/openvz/container.rb', line 31

def ctid
  @ctid
end

#rw config(config) ⇒ Object

OpenVZ::Container

Examples:

Sample Usage

c = Container.new("999")
c.start
c.stop
c.restart
c.mount
c.umount
c.destroy

Configration Access

c = Container.new("999")
puts c.config.privvmpages
c.config.privvmpages = "123:123"

Container Creation

c = Container.new("999")
c.create( :ostemplate => "debian-6.0-bootstrap", :config => "vps.unlimited" )
c.debootstrap( :dist => "squeeze", :mirror => "http://ftp.at.debian.org" )
c.cp_into(:src => "/etc/resolv.conf", :dest => "/etc/resolv.conf")
c.start
c.command("hostname -f")

Author:

  • Stefan Schlesinger



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# File 'lib/openvz/container.rb', line 28

class Container

    attr_accessor :config
    attr_reader :ctid

    class StatemachineError < StandardError;end
    class Config            < ::OpenVZ::ConfigHash ; end


    def initialize(ctid=false)
        @ctid       = ctid
        @vzctl      = "/usr/sbin/vzctl"
        @configfile = "/etc/vz/conf/#{ctid}.conf"

        @config     = Config.new(load_config_file)
        @config.add_observer(self)
    end


    # Start a container
    #
    def start
        cmd = "#{@vzctl} start #{@ctid}"
        execute(cmd)
    end


    # Stop a container
    #
    def stop
        cmd = "#{@vzctl} stop #{@ctid}"
        execute(cmd)
    end


    # Restart a container
    #
    def restart
        cmd = "#{@vzctl} restart #{@ctid}"
        execute(cmd)
    end


    # Mount a container
    #
    def mount
        cmd = "#{@vzctl} mount #{@ctid}"
        execute(cmd)
    end


    # Umount a container
    #
    def umount
        cmd = "#{@vzctl} umount #{@ctid}"
        execute(cmd)
    end


    # Destroy a container
    #
    def destroy
        cmd = "#{@vzctl} destroy #{@ctid}"
        execute(cmd)
    end


    # Checkpoint the container
    #
    def checkpoint(snapshot_path)
        cmd = "#{@vzctl} chkpnt #{@ctid} --dumpfile #{snapshot_path}"
        execute(cmd)
    end


    # Restore a checkpoint
    #
    def restore(snapshot_path)
        cmd = "#{@vzctl} restore #{@ctid} --dumpfile #{snapshot_path}"
        execute(cmd)
    end


    # Update one or multiple Container properties and keep the configration
    # object up to date
    #
    # @param [Hash] The options to update, eg. `{ :privvmpages => '123:123' }`
    def set(options = {})
        # Construct a set command
        cmd = "#{@vzctl} set #{@ctid} --save"

        options.each do |opt,val|
            cmd << " --#{opt}"
            cmd << " #{val}"
        end

        execute(cmd)

        # Each time we update a setting, reload the configuration.
        @config.load(@ctid)
    end


    # Create a new empty instance from a template.
    #
    # @example Create a new empty container from a template.
    #   The following example will create a container, from an empty
    #   template, which can be used to bootstrap the whole installation
    #   later on. It will as well apply the vps.unlimited template config.
    #
    #   container.create(:ostemplate => "debian-6.0-bootstrap", :config => "vps.unlimited")
    #
    # @param [Hash] options you want to pass to the create statement.
    def create(options={})
        unless options[:ostemplate]
            # We need at least a valid ostemplate
            raise ArgumentError, "Create requires argument :ostemplate."
        end

        cmd = "#{@vzctl} create #{@ctid}"

        options.each do |opt,val|
            cmd << " --#{opt}"
            cmd << " #{val}"
        end

        execute(cmd)

        Log.debug("Reading new container configuration file: #{@configfile}")
        @config     = Config.new(load_config_file)
        @config.add_observer(self)
    end


    # Bootstrap a Debian container, this requires /usr/sbin/debootstrap to
    # be installed. Executing this function usually takes a while.
    #
    # @example Debootstrap a container object.
    #   container.debootstrap(:dist => "squeeze", :mirror => "http://cdn.debian.net/debian")
    #
    # @example Debootstrap a container, include and exclude certain packages.
    #   container.debootstrap(
    #       :dist    => "squeeze",
    #       :mirror  => "http://cdn.debian.net/debian",
    #       :include => "libreadline6,screen,file,less,dnsutils,tcpdump,vim-nox,puppet,facter",
    #       :exclude => "dhcp-client,dhcp3-client,dhcp3-common,dmidecode,gcc-4.2-base,module-init-tools,tasksel,tasksel-data,libdb4.4,libsasl2-2,libgnutls26,libconsole,libgnutls13,libtasn1-3,liblzo2-2,libopencdk10,libgcrypt11",
    #   )
    #
    # @param [Hash] options you want to pass to the bootstrapping tool.
    def debootstrap(options={})
        cmd  = "/usr/sbin/debootstrap"

        options.each do |opt,val|
            unless opt.to_s =~ /dist|dest|mirror/
                cmd << " --#{opt} #{val}"
            end
        end

        cmd << " #{options[:dist]}"
        cmd << " #{@config.ve_private}"
        cmd << " #{options[:mirror]}"

        execute(cmd)

        # FIXME - Remove gettys from inititab automatically. We
        # Need a searchandreplace function first... :-)
        #
        # Util.searchandreplace( "#{@config.ve_private}/etc/inittab",
        #                        "/^(?!#)(.*\/sbin\/getty)/", 
        #                        '#\1')
    end


    # Copy a file from the hardware node into the container.
    #
    # @example Copy resolv.conf
    #     container.cp_into(
    #          :src => '/etc/resolv.conf',
    #          :dst => '/etc/resolv.conf'
    #     )
    #
    # @param [Hash] define
    def cp_into(options={})
        cmd = "/bin/cp #{options[:src]} #{@config.ve_private}/#{options[:dst]}"
        execute(cmd)
    end


    # Run a shell command within the container.
    #
    # @example Update the package sources.
    #    container.command("aptitude update")
    #
    # @param [String] Command to be executed.
    def command(command)
        cmd = "#{@vzctl} exec2 #{@ctid} "
        cmd << command
        execute(cmd)
    end


    # Return the current machine status string.
    # 
    # @example
    #   puts container.status()
    #   exist mounted running
    def status
        cmd = "#{@vzctl} status #{@ctid}"
        status = execute(cmd).split(/\s/)
        Log.debug("Container (#{@ctid}) status requested: #{status}")
        status.drop(2)
    end


    # Return the current uptime in seconds.
    # Return zero if the container is not running.
    #
    # @example
    #   puts container.uptime()
    #   1188829
    def uptime
      return 0 unless status.include? "running"
      raw = command "cat /proc/uptime"
      Log.debug("Container (#{@ctid}) uptime requested: #{raw}")
      raw.split(/\W/).first.to_i
    end


    ####
    #### Helper methods
    ####


    def state_require(*opts)
        current_state = status
        if current_state & opts
            puts "req: #{opts.join("-")}, cur: #{current_state.join("-")}"
            return true
        else
          raise StateMachineError, "Required container status not met for this action. req: #{opts.join("-")}, cur: #{current_state.join("-")}"
        end
    end


    # Check whether current_state == :require||:validate
    #
    def state(mode, action)
        current_state = self.status()

        if current_state & @statemachine_options[action.to_sym][mode.to_sym]
            return true
        end

        raise StateMachineError,
           "Required container status not met. req: #{@state_control[:action]}, cur: #{state}"
    end


    # Notify Method! :-) Config objects will notify, as soon as they are changed.
    #
    def update(key, value)
        set(key.to_sym => value)
    end


    # Load the container configration file.
    #
    def load_config_file
        data = {}
        if File.exists?(@configfile)
            File.open(@configfile, "r").each_line do |line|
                # strip blank spaces, tabs etc. off the lines
                line.gsub!(/\s*$/, "")
    
                if (line =~ /^([^=]+)="([^=]*)"$/)
                    key = $1.downcase
                    val = $2
    
                    case key
                        when /^ve_(private|root)$/
                            data[key] = val.gsub!(/\$VEID/, @ctid)
                        else
                            data[key] = val
                    end
                end
            end
        end
        data
    end


    # TODO: implement :-)
    #
    # NETIF="ifname=eth0,
    #        bridge=vzbr303,
    #        mac=02:01:79:15:03:02,
    #        host_ifname=veth17915.303,
    #        host_mac=12:01:79:15:03:02"
    #def load_net_config
    #    if @config.netif ### DOES THAT WORK?
    #        str = @config.netif

    #        if str =~ /ifname=([^,]+),bridge=([^,]+),mac=([^,]+),host_ifname=([^,]+),host_mac=([^,]+)/
    #            @net.ifname      = $1
    #            @net.bridge      = $2
    #            @net.mac         = $3
    #            @net.host_ifname = $4
    #            @net.host_mac    = $5
    #            @net.type        = "bridged"
    #            ### MISSING: IP, SUBNET, GATEWAY within VM
    #        end
    #    end
    #end

    # This will give us a nicer object feeling and dynamically
    # exposes variables to the outside.
    #
    # @examples Setting and getting a variable
    # container.config.ipaddress = 1.2.3.4
    #
    #
    #def method_missing(sym, *args)
    #  if sym.to_s =~ /(.+)=$/
    #    self[$1] = args.first
    #  else
    #    self[sym]
    #  end
    #end


    # Execute a System Command
    def execute(cmd)

        Log.debug("#{cmd}")

        s = Shell.new("#{cmd}", :cwd => "/tmp")
        s.runcommand
        if s.status.exitstatus != 0
            raise "Cannot execute: '#{cmd}'. Return code: #{s.status.exitstatus}. Stderr: #{s.stderr}"
        end
        s.stdout
    end
end

Instance Method Details

#checkpoint(snapshot_path) ⇒ Object

Checkpoint the container



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# File 'lib/openvz/container.rb', line 97

def checkpoint(snapshot_path)
    cmd = "#{@vzctl} chkpnt #{@ctid} --dumpfile #{snapshot_path}"
    execute(cmd)
end

#command(command) ⇒ Object

Run a shell command within the container.

Examples:

Update the package sources.

container.command("aptitude update")

Parameters:

  • Command (String) —

    to be executed.



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# File 'lib/openvz/container.rb', line 222

def command(command)
    cmd = "#{@vzctl} exec2 #{@ctid} "
    cmd << command
    execute(cmd)
end

#cp_into(options = {}) ⇒ Object

Copy a file from the hardware node into the container.

Examples:

Copy resolv.conf

container.cp_into(
     :src => '/etc/resolv.conf',
     :dst => '/etc/resolv.conf'
)

Parameters:

  • define (Hash) 


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# File 'lib/openvz/container.rb', line 210

def cp_into(options={})
    cmd = "/bin/cp #{options[:src]} #{@config.ve_private}/#{options[:dst]}"
    execute(cmd)
end

#create(options = {}) ⇒ Object

Create a new empty instance from a template.

Examples:

Create a new empty container from a template.

The following example will create a container, from an empty
template, which can be used to bootstrap the whole installation
later on. It will as well apply the vps.unlimited template config.

container.create(:ostemplate => "debian-6.0-bootstrap", :config => "vps.unlimited")

Parameters:

  • options (Hash) (defaults to: {}) —

    you want to pass to the create statement.



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# File 'lib/openvz/container.rb', line 141

def create(options={})
    unless options[:ostemplate]
        # We need at least a valid ostemplate
        raise ArgumentError, "Create requires argument :ostemplate."
    end

    cmd = "#{@vzctl} create #{@ctid}"

    options.each do |opt,val|
        cmd << " --#{opt}"
        cmd << " #{val}"
    end

    execute(cmd)

    Log.debug("Reading new container configuration file: #{@configfile}")
    @config     = Config.new(load_config_file)
    @config.add_observer(self)
end

#debootstrap(options = {}) ⇒ Object

Bootstrap a Debian container, this requires /usr/sbin/debootstrap to be installed. Executing this function usually takes a while.

Examples:

Debootstrap a container object.

container.debootstrap(:dist => "squeeze", :mirror => "http://cdn.debian.net/debian")

Debootstrap a container, include and exclude certain packages.

container.debootstrap(
    :dist    => "squeeze",
    :mirror  => "http://cdn.debian.net/debian",
    :include => "libreadline6,screen,file,less,dnsutils,tcpdump,vim-nox,puppet,facter",
    :exclude => "dhcp-client,dhcp3-client,dhcp3-common,dmidecode,gcc-4.2-base,module-init-tools,tasksel,tasksel-data,libdb4.4,libsasl2-2,libgnutls26,libconsole,libgnutls13,libtasn1-3,liblzo2-2,libopencdk10,libgcrypt11",
)

Parameters:

  • options (Hash) (defaults to: {}) —

    you want to pass to the bootstrapping tool.



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# File 'lib/openvz/container.rb', line 177

def debootstrap(options={})
    cmd  = "/usr/sbin/debootstrap"

    options.each do |opt,val|
        unless opt.to_s =~ /dist|dest|mirror/
            cmd << " --#{opt} #{val}"
        end
    end

    cmd << " #{options[:dist]}"
    cmd << " #{@config.ve_private}"
    cmd << " #{options[:mirror]}"

    execute(cmd)

    # FIXME - Remove gettys from inititab automatically. We
    # Need a searchandreplace function first... :-)
    #
    # Util.searchandreplace( "#{@config.ve_private}/etc/inittab",
    #                        "/^(?!#)(.*\/sbin\/getty)/", 
    #                        '#\1')
end

#destroy ⇒ Object

Destroy a container



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# File 'lib/openvz/container.rb', line 89

def destroy
    cmd = "#{@vzctl} destroy #{@ctid}"
    execute(cmd)
end

#execute(cmd) ⇒ Object

Execute a System Command



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# File 'lib/openvz/container.rb', line 359

def execute(cmd)

    Log.debug("#{cmd}")

    s = Shell.new("#{cmd}", :cwd => "/tmp")
    s.runcommand
    if s.status.exitstatus != 0
        raise "Cannot execute: '#{cmd}'. Return code: #{s.status.exitstatus}. Stderr: #{s.stderr}"
    end
    s.stdout
end

#load_config_file ⇒ Object

Load the container configration file.



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# File 'lib/openvz/container.rb', line 295

def load_config_file
    data = {}
    if File.exists?(@configfile)
        File.open(@configfile, "r").each_line do |line|
            # strip blank spaces, tabs etc. off the lines
            line.gsub!(/\s*$/, "")

            if (line =~ /^([^=]+)="([^=]*)"$/)
                key = $1.downcase
                val = $2

                case key
                    when /^ve_(private|root)$/
                        data[key] = val.gsub!(/\$VEID/, @ctid)
                    else
                        data[key] = val
                end
            end
        end
    end
    data
end

#mount ⇒ Object

Mount a container



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# File 'lib/openvz/container.rb', line 73

def mount
    cmd = "#{@vzctl} mount #{@ctid}"
    execute(cmd)
end

#restart ⇒ Object

Restart a container



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# File 'lib/openvz/container.rb', line 65

def restart
    cmd = "#{@vzctl} restart #{@ctid}"
    execute(cmd)
end

#restore(snapshot_path) ⇒ Object

Restore a checkpoint



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# File 'lib/openvz/container.rb', line 105

def restore(snapshot_path)
    cmd = "#{@vzctl} restore #{@ctid} --dumpfile #{snapshot_path}"
    execute(cmd)
end

#set(options = {}) ⇒ Object

Update one or multiple Container properties and keep the configration object up to date

Parameters:

  • The (Hash) —

    options to update, eg. ‘{ :privvmpages => ’123:123’ }‘



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# File 'lib/openvz/container.rb', line 115

def set(options = {})
    # Construct a set command
    cmd = "#{@vzctl} set #{@ctid} --save"
    
    options.each do |opt,val|
        cmd << " --#{opt}"
        cmd << " #{val}"
    end

    execute(cmd)

    # Each time we update a setting, reload the configuration.
    @config.load(@ctid)
end

#start ⇒ Object

Start a container



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# File 'lib/openvz/container.rb', line 49

def start
    cmd = "#{@vzctl} start #{@ctid}"
    execute(cmd)
end

#state(mode, action) ⇒ Object

Check whether current_state == :require||:validate

Raises:

  • (StateMachineError) 


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# File 'lib/openvz/container.rb', line 274

def state(mode, action)
    current_state = self.status()

    if current_state & @statemachine_options[action.to_sym][mode.to_sym]
        return true
    end

    raise StateMachineError,
       "Required container status not met. req: #{@state_control[:action]}, cur: #{state}"
end

#state_require(*opts) ⇒ Object 



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# File 'lib/openvz/container.rb', line 261

def state_require(*opts)
    current_state = status
    if current_state & opts
        puts "req: #{opts.join("-")}, cur: #{current_state.join("-")}"
        return true
    else
      raise StateMachineError, "Required container status not met for this action. req: #{opts.join("-")}, cur: #{current_state.join("-")}"
    end
end

#status ⇒ Object

Return the current machine status string.

Examples:

puts container.status()
exist mounted running


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# File 'lib/openvz/container.rb', line 234

def status
    cmd = "#{@vzctl} status #{@ctid}"
    status = execute(cmd).split(/\s/)
    Log.debug("Container (#{@ctid}) status requested: #{status}")
    status.drop(2)
end

#stop ⇒ Object

Stop a container



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# File 'lib/openvz/container.rb', line 57

def stop
    cmd = "#{@vzctl} stop #{@ctid}"
    execute(cmd)
end

#umount ⇒ Object

Umount a container



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# File 'lib/openvz/container.rb', line 81

def umount
    cmd = "#{@vzctl} umount #{@ctid}"
    execute(cmd)
end

#update(key, value) ⇒ Object

Notify Method! :-) Config objects will notify, as soon as they are changed.



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# File 'lib/openvz/container.rb', line 288

def update(key, value)
    set(key.to_sym => value)
end

#uptime ⇒ Object

Return the current uptime in seconds. Return zero if the container is not running.

Examples:

puts container.uptime()
1188829


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# File 'lib/openvz/container.rb', line 248

def uptime
  return 0 unless status.include? "running"
  raw = command "cat /proc/uptime"
  Log.debug("Container (#{@ctid}) uptime requested: #{raw}")
  raw.split(/\W/).first.to_i
end