monitor: use nice to run commands with low priority, update README and free disk promise message

stack/monitor/buildout.cfg

@@ -89,7 +89,7 @@ md5sum = 683ea85fc054094248baf5752dd089bf
 [monitor-check-free-disk-space]
 <= monitor-template-base
 filename = check_free_disk.in
-md5sum = bc61a77f8c06615dfa687ed48893bbc1
+md5sum = e48f3804dc367e51a70063ab0e589e9e
 # End templates files
 
 # XXX keep compatibility (with software/ipython_notebook/software.cfg )
@@ -102,7 +102,7 @@ recipe = slapos.recipe.template:jinja2
 filename = template-monitor.cfg
 template = ${:_profile_base_location_}/instance-monitor.cfg.jinja2.in
 rendered = ${buildout:directory}/template-monitor.cfg
-md5sum = be07297494e08377c4dfecb26c2919ef
+md5sum = 2c2aacb9fa97e35818bfa4543dffcb5a
 context =
     key apache_location apache:location
     key gzip_location gzip:location

stack/monitor/instance-monitor.cfg.jinja2.in

@@ -102,13 +102,14 @@ parameter-list =
   raw monitor-user ${monitor-instance-parameter:username}
   htpasswd monitor-password ${monitor-htpassword-file:password-file} ${monitor-instance-parameter:username} ${httpd-monitor-htpasswd:htpasswd-path}
   file promise-timeout ${monitor-promise-timeout-file:file}
-  file free-disk-space-MB ${promise-check-free-disk-space:config-file}
+  file min-free-disk-MB ${promise-check-free-disk-space:config-file}
   ${monitor-instance-parameter:instance-configuration}
 # htpasswd entry:  htpasswd key password-file username htpasswd-file
 
 collector-db = ${monitor-instance-parameter:collector-db}
 collect-script = {{ monitor_collect }}
 python = {{ python_with_eggs }}
+nice-cmd = ${xnice-bin:output}
 
 promise-output-file = ${directory:monitor}/monitor-bootstrap-status
 
@@ -230,9 +231,17 @@ context =
     raw dash_binary {{ dash_executable_location }}
 command = kill -USR1 $(cat ${monitor-httpd-conf-parameter:pid-file})
 
+[xnice-bin]
+recipe = collective.recipe.template
+input = inline:#!/bin/sh
+  # run something at lowest possible priority
+  exec nice -19 chrt --idle 0 ionice -c3 "$@"
+output = ${directory:bin}/xnice
+mode = 700
+
 [monitor-globalstate-wrapper]
 recipe = slapos.cookbook:wrapper
-command-line = {{ monitor_genstatus }} '${monitor-conf:rendered}' '${monitor-instance-info:rendered}'
+command-line = ${xnice-bin:output} {{ monitor_genstatus }} '${monitor-conf:rendered}' '${monitor-instance-info:rendered}'
 wrapper-path = ${directory:bin}/monitor-globalstate
 
 [monitor-configurator-wrapper]

stack/monitor/templates/check_free_disk.in

@@ -34,10 +34,10 @@ if __name__ == '__main__':
         value = int(min_size_str)
         if value >= 200:
           # Minimum value is 200Mb, it's already low
-          min_free_size = int(min_size_str)*1024
+          min_free_size = int(min_size_str)*1024*1024
   else:
     with open(config_file, 'w') as f:
-      f.write(str(min_free_size/1024))
+      f.write(str(min_free_size/(1024*1024)))
   real_free_space = user_free_space(home_path)
   if real_free_space > min_free_size:
     print "Free disk space: OK"
@@ -45,7 +45,7 @@ if __name__ == '__main__':
 
   real_space_g = round(real_free_space/(1024.0*1024*1024), 2)
   min_space_g = round(min_free_size/(1024.0*1024*1024), 2)
-  print 'Free disk space slow: remaning %s G, min is %s G' % (
+  print 'Free disk space low: remaning %s G (threshold: %s G)' % (
     real_space_g, min_space_g)
   print 'You can modify minimum value on your monitor interface.'
   exit(1)