ecn-robots/pgdb.py

'Python interface to PostgreSQL for managing database nodes.'

from subprocess import Popen, PIPE

class Db(object):
    
    def __init__(self,name):
        self._name = name
        self._p = Popen('/usr/bin/psql -Aqt -U postgres', stdin=PIPE, stdout=PIPE, stderr=PIPE, shell=True)

    def _run(self, command,args=[]):
        execfn = [command] + list(args)
	try:
            p = Popen(execfn, stdout=PIPE, stderr=PIPE)
	    return p.communicate()
        except Exception,e:
	    print str(e)
	return -1

    def _runsql(self, sql, db='postgres'):
	given_sql = sql
        sql = sql +'\echo this is the end' +'\n'
        self._p.stdout.flush()
        self._p.stdin.write(str(sql))
	out = ""
	out  = self._p.stdout.readline()
	while out.find("this is the end") == -1:
	    out = out +self._p.stdout.readline()
        lout = out.replace('this is the end','')
	return lout.strip()
    
    def _get_owner(self):
        sql = "SELECT pg_get_userbyid(datdba) FROM pg_database WHERE datname ='"+self.sanitize(self._name)+"';"
	own = self._runsql(sql)
        return own

    def _set_owner(self, owner):
        sql = "ALTER DATABASE "+self._name+" OWNER TO "+self.sanitize(owner)+";"
        own = self._runsql(sql)
	return own
    
    db_owner = property(_get_owner, _set_owner)

    @property
    def db_OID(self):
        sql = "SELECT oid FROM pg_database WHERE datname = '"+self.sanitize(self._name)+"';"
	oid = self._runsql(sql)
	return oid

    @property
    def db_info(self):
        information = {'size':'', 'encoding':'', 'collation':'','ctype':''}
        information['size'] = self._runsql("SELECT pg_size_pretty(pg_database_size('"+self.sanitize(self._name)+"'));")
        information['encoding'], information['collation'], \
	    information['ctype'] = self._runsql("SELECT pg_encoding_to_char(encoding), datcollate, datctype FROM pg_database WHERE datname='"+self.sanitize(self._name)+"';").split('|')
        return information

    @property
    def db_connections(self):
        sql = "SELECT numbackends from pg_stat_database WHERE datname = '"+self.sanitize(self._name)+"';"
	cncs = self._runsql(sql)
	return cncs
    
    def user_exists(self, user):
        sql = "SELECT rolname FROM pg_authid WHERE rolname = '"+self.sanitize(user)+"';"
	u = self._runsql(sql)
	if (u == ""):
	    return False
	return True

    def db_exists(self, xdb):
        sql = "SELECT datname FROM pg_database WHERE datname = '"+self.sanitize(xdb)+"';"
	d = self._runsql(sql)
        if (d == ""):
	    return False
	return True

    def db_delete(self):
        if self.db_exists(self._name) == True:
            sql = "DROP DATABASE "+self.sanitize(self._name)+";"
	    drop = self._runsql(sql)
	    return drop
        return "Failed"

    def db_create(self, own, coll, ctyp, enc=u'UTF8'):
        if self.db_exists(self._name) == False:
	    sql = "CREATE DATABASE "+self.sanitize(self._name)+" WITH OWNER = "+self.sanitize(own)+" ENCODING = '"+self.sanitize(enc)+"' LC_COLLATE = '"+self.sanitize(coll)+"' LC_CTYPE = '"+self.sanitize(ctyp)+"';"
	    create = self._runsql(sql)
	    return create
        return "Failed"

    def db_dump(self, path, method):
        dump = Popen(['/usr/bin/pg_dump', '-U','postgres','-F'+ method, self._name], stdout=PIPE)
	fl = open(path,"wb")
	gz = Popen(['gzip'], stdin = dump.stdout, stdout = fl)
	fl.close
	return "Finished dumping "+self._name


    def db_rename(self,old, new):
        if self.db_exists(new) == True or self.db_exists(old) == False:
	    return "Cannot"
	sql = "ALTER DATABASE "+self.sanitize(old)+" RENAME TO "+self.sanitize(new)+";"
	rename = self._runsql(sql)
	return rename

    def copy():
        pass

    def db_list(self):
        sql = "SELECT datname FROM pg_database WHERE datname NOT IN ('template0', 'template1', 'postgres');"
	dbl = self._runsql(sql)
	return dbl

    def usr_list(self):
        sql = "SELECT rolname FROM pg_authid WHERE rolcanlogin=true;"
	usrl = self._runsql(sql)
	return usrl

    def usr_add(self, us, passw):
        sql = "CREATE ROLE "+self.sanitize(us)+" WITH NOSUPERUSER NOCREATEDB NOCREATEROLE NOCREATEUSER LOGIN PASSWORD '"+self.sanitize(passw)+"';"
        usra = self._runsql(sql)
        return usra

    def usr_delete(self, us):
        sql = "DROP ROLE IF EXISTS "+self.sanitize(us)+";"
        usrd = self._runsql(sql)
        return usrd
    
    def sanitize(self,s):
        mset = '0123456789ABCDEFGHIJKLMNOPRSTUVXYZabcdefghijklmnoprstuvxyz-_.'
        return ''.join([c for c in s if c in mset])

def _test():
    test = Db(u'postgres')
    print    test.db_list()
    print    test.usr_list()
    print test.db_info['encoding'], test.info['collation'], test.info['ctype']
    print test.sanitize("aaaa-fgdg?sd/!_fb*gs'h;s'hdghj.dn ")
if __name__ == '__main__':
    _test()