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Viewing changes to hooks/charmhelpers/contrib/hahelpers/cluster.py

  • Committer: James Page
  • Date: 2015-01-13 09:19:48 UTC
  • mfrom: (70 trunk)
  • mto: This revision was merged to the branch mainline in revision 95.
  • Revision ID: james.page@ubuntu.com-20150113091948-2xyc9gnqoc1jkxma
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hooks/charmhelpers/contrib/hahelpers/cluster.py
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import subprocess
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import os
 
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from socket import gethostname as get_unit_hostname
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import six
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    WARNING,
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    unit_get,
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)
 
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from charmhelpers.core.decorators import (
 
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    retry_on_exception,
 
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)
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class HAIncompleteConfig(Exception):
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    pass
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class CRMResourceNotFound(Exception):
 
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    pass
 
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def is_elected_leader(resource):
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    """
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    Returns True if the charm executing this is the elected cluster leader.
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    return False
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def is_crm_leader(resource):
 
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@retry_on_exception(5, base_delay=2, exc_type=CRMResourceNotFound)
 
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def is_crm_leader(resource, retry=False):
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    """
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    Returns True if the charm calling this is the elected corosync leader,
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    as returned by calling the external "crm" command.
 
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    We allow this operation to be retried to avoid the possibility of getting a
 
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    false negative. See LP #1396246 for more info.
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    """
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    cmd = [
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        "crm", "resource",
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        "show", resource
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    ]
 
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    cmd = ['crm', 'resource', 'show', resource]
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    try:
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        status = subprocess.check_output(cmd).decode('UTF-8')
 
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        status = subprocess.check_output(cmd, stderr=subprocess.STDOUT)
 
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        if not isinstance(status, six.text_type):
 
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            status = six.text_type(status, "utf-8")
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    except subprocess.CalledProcessError:
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        return False
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    else:
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        if get_unit_hostname() in status:
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            return True
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        else:
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            return False
 
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        status = None
 
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    if status and get_unit_hostname() in status:
 
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        return True
 
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    if status and "resource %s is NOT running" % (resource) in status:
 
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        raise CRMResourceNotFound("CRM resource %s not found" % (resource))
 
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    return False
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def is_leader(resource):