plugins/omf_resctl.py

   1 #
   2 # NodeManager plugin - first step of handling omf_controlled slices
   3 #
   4
   5 """
   6 Overwrites the 'resctl' tag of slivers controlled by OMF so slivermanager.py does the right thing
   7 """
   8
   9 import os, os.path
  10 import glob
  11 import subprocess
  12
  13 import tools
  14 import logger
  15
  16 priority = 50
  17
  18 def start():
  19     pass
  20
  21 ### the new template for v6
  22 # hard-wire this for now
  23 # once the variables are expanded, this is expected to go into
  24 config_ple_template="""---
  25 # Example:
  26 # _slicename_ = nicta_ruby
  27 # _hostname_ = planetlab1.research.nicta.com.au
  28 # _xmpp_server_ = xmpp.planet-lab.eu
  29
  30 :uid: _slicename_@_hostname_
  31 :uri: xmpp://_slicename_-_hostname_-<%= "#{Process.pid}" %>:_slicename_-_hostname_-<%= "#{Process.pid}" %>@_xmpp_server_
  32 :environment: production
  33 :debug: false
  34
  35 :auth:
  36   :root_cert_dir: /home/_slicename_/root_certs
  37   :entity_cert: /home/_slicename_/entity.crt
  38   :entity_key: /home/_slicename_/.ssh/id_rsa
  39 """
  40
  41 # the path where the config is expected from within the sliver
  42 yaml_slice_path="/etc/omf_rc/config.yml"
  43 # the path for the script that we call when a change occurs
  44 omf_rc_trigger_script="omf_rc_plc_trigger"
  45
  46 ### this returns the kind of virtualization on the node
  47 # either 'vs' or 'lxc'
  48 # also caches it in /etc/planetlab/virt for next calls
  49 # could be promoted to core nm if need be
  50 virt_stamp="/etc/planetlab/virt"
  51 def get_node_virt ():
  52     try:
  53         return file(virt_stamp).read().strip()
  54     except:
  55         pass
  56     logger.log("Computing virt..")
  57     vs_retcod=subprocess.call ([ 'vserver', '--help' ])
  58     if vs_retcod == 0:
  59         virt='vs'
  60     else:
  61         virt='lxc'
  62     with file(virt_stamp,"w") as f:
  63         f.write(virt)
  64     return virt
  65
  66 def command_in_slice (slicename, argv):
  67     # with vserver this can be done using vserver .. exec <trigger-script>
  68     # with lxc this is less clear as we are still discussing how lxcsu should behave
  69     # ideally we'd need to run lxcsu .. <trigger-script>
  70     virt=get_node_virt()
  71     if virt=='vs':
  72         return [ 'vserver', slicename, 'exec', ] + argv
  73     elif virt=='lxc':
  74         return [ 'lxcsu', slicename, ] + argv
  75     logger.log("command_in_slice: WARNING: could not find a valid virt")
  76     return argv
  77
  78 def GetSlivers(data, conf = None, plc = None):
  79     logger.log("omf_resctl.GetSlivers")
  80     if 'accounts' not in data:
  81         logger.log_missing_data("omf_resctl.GetSlivers",'accounts')
  82         return
  83
  84     try:
  85         xmpp_server=data['xmpp']['server']
  86         if not xmpp_server:
  87             # we have the key but no value, just as bad
  88             raise Exception
  89     except:
  90         # disabled feature - bailing out
  91         logger.log("omf_resctl: PLC_OMF config unsufficient (not enabled, or no server set), -- plugin exiting")
  92         return
  93
  94     hostname = data['hostname']
  95
  96     def is_omf_friendly (sliver):
  97         for chunk in sliver['attributes']:
  98             if chunk['tagname']=='omf_control': return True
  99
 100     for sliver in data['slivers']:
 101         # skip non OMF-friendly slices
 102         if not is_omf_friendly (sliver): continue
 103         slicename=sliver['name']
 104         yaml_template = config_ple_template
 105         yaml_contents = yaml_template\
 106             .replace('_xmpp_server_',xmpp_server)\
 107             .replace('_slicename_',slicename)\
 108             .replace('_hostname_',hostname)
 109         yaml_full_path="/vservers/%s/%s"%(slicename,yaml_slice_path)
 110         yaml_full_dir=os.path.dirname(yaml_full_path)
 111         if not os.path.isdir(yaml_full_dir):
 112             try: os.makedirs(yaml_full_dir)
 113             except OSError: pass
 114
 115         config_changes=tools.replace_file_with_string(yaml_full_path,yaml_contents)
 116         logger.log("yaml_contents length=%d, config_changes=%r"%(len(yaml_contents),config_changes))
 117         # would make sense to also check for changes to authorized_keys
 118         # would require saving a copy of that some place for comparison
 119         # xxx todo
 120         keys_changes = False
 121         if config_changes or keys_changes:
 122             # instead of restarting the service we call a companion script
 123             try:
 124                 # the trigger script actually needs to be run in the slice context of course
 125                 # xxx we might need to use
 126                 # slice_command=['bash','-l','-c',omf_rc_trigger_script]
 127                 slice_command = [omf_rc_trigger_script]
 128                 to_run = command_in_slice (slicename, slice_command)
 129                 sp=subprocess.Popen(to_run, stdout=subprocess.PIPE,stderr=subprocess.STDOUT)
 130                 (out,err)=sp.communicate()
 131                 retcod=sp.returncode
 132                 # we don't wait for that, try to display a retcod for info purpose only
 133                 # might be None if that config script lasts or hangs whatever
 134                 logger.log("omf_resctl: %s: called OMF rc control script (imm. retcod=%r)"%(slicename,retcod))
 135                 logger.log("omf_resctl: got stdout\n%s"%out)
 136                 logger.log("omf_resctl: got stderr\n%s"%err)
 137             except:
 138                 import traceback
 139                 traceback.print_exc()
 140                 logger.log_exc("omf_resctl: WARNING: Could not call trigger script %s"%\
 141                                    omf_rc_trigger_script, name=slicename)
 142         else:
 143             logger.log("omf_resctl: %s: omf_control'ed sliver has no change" % slicename)