class ClusterMgr(object):
'''
The ClusterMgr provides an interface to create and remove clusters
as well as list active clusters. Internally it uses a MongoDB
instance for persistence
__init__ - constructor that connects to the database
list_clusters - list all clusters
alloc_new - allocate a new cluster instance using a ConfigSpec
remove - removes a cluster
'''
def __init__(self):
'''
Constructor
'''
self._dbcon = AutoOamMongo()
self._db = self._dbcon.db().clusters
def list_clusters(self):
'''Returns the list of clusters as (name, id) tuples.'''
ret = []
for c in self._db.find():
name='ERROR -no name'
try:
name=c['name']
except:
pass
ret.append( (str(name), str(c['_id'])) )
return ret
def alloc_new(self,name, configspec, vmitype, chefmode=True):
'''Allocates a new cluster.
@param name - name for the cluster (ideally unique)
@param configspec - a ConfigSpec instance
@param vmitype - string specifying vmi type (supported: 'vagrant')
'''
cid = self._db.insert({})
try:
configspec.validate()
cluster = Cluster( name, configspec, cid, chefmode=chefmode )
VMI.Create(vmitype, cluster)
self._db.update(
{ '_id' : cluster.id() },
{ u'name' : name,
u'config' : configspec.jsonmap,
u'vmi' : cluster.get_vmi().jsonmap(),
u'machines' : cluster.machines()} )
except Exception as exc:
import traceback
Log.error('Cluster creation failed: %s' % exc)
Log.error( traceback.format_exc() )
self._db.remove( { '_id' : cid } )
raise Exception('Failed to create cluster: %s' % name)
return cluster
def attach(self,name):
'''Attempts to attach to an existing cluster.
@param name - cluster name to attach to
raises eusterception of number found is not found
'''
try:
cursor = self._db.find({'name' : name})
defn = cursor[0]
cluster = Cluster(defn['name'], ConfigSpec(json.dumps(defn['config'])), defn['_id'],machines=defn['machines'], attach=True)
VMI.Attach(cluster, defn['vmi'])
return cluster
except Exception as err:
raise Exception("Error attaching to cluster %s: %s!" % (name,err))
def destroy(self,cluster):
'''Destroys the cluster and removes from the database. DESTRUCTIVE operation.'''
crit = { '_id' : cluster.id() }
clusterdefn = self._db.find_one( crit )
if not clusterdefn:
Log.error("Cluster id %s not in database!" % cluster.id())
else:
try:
cluster.destroy()
self._db.remove( crit )
return True
except Exception as err:
Log.error("Unable to destroy cluster: %s" % err)
return False
def destroy_by_id(self,idnum):
'''Destroys the cluster and removes from the database. DESTRUCTIVE operation.'''
crit = { '_id' : self._dbcon.getobjectid( idnum ) }
clusterdefn = self._db.find_one( crit )
if not clusterdefn:
Log.error("id %s not in database!" % idnum)
else:
try:
self._db.remove( crit )
return True
except Exceptionoammongo.py as err:
Log.error("Unable to destroy cluster by id: %s" % err)
return False
