"""
Dump database schema and content
"""
import logging
import subprocess
import tempfile
import os
logger = logging.getLogger(__name__)
[docs]def dump_db(engine, hostname, port, dbname, dbuser, dbpass, output):
"""
Dumps a database
Args:
engine: the name of the database system (either monetdb or postgresql)
hostname: the hostname of the database
port: the port of the database server
dbname: the database name to be dumped
dbuser: the user authorised to do the dump
dbpass: the pw for the user
output: the output file to which the dump is written
"""
if engine == "monetdb":
return dump_monetdb(hostname, port, dbname, dbuser, dbpass, output)
elif engine == "postgresql":
return dump_pg(hostname, port, dbname, dbuser, dbpass, output)
else:
raise NotImplementedError("Not able to dump %s" % (engine,))
[docs]def dump_monetdb(hostname, port, dbname, dbuser, dbpass, output_filename):
"""
Dumps a MonetDB database in specified output file
"""
mclient_executable = "mclient"
with tempfile.NamedTemporaryFile() as dotmonetdb, \
open(output_filename, 'w') as output_file:
# NB we need to write *both* user and password into the dotmonetdb
# file: writing just the password will fail.
dotmonetdb.write("user=%s\n" % (dbuser,))
dotmonetdb.write("password=%s\n" % (dbpass,))
dotmonetdb.flush()
try:
env = os.environ
env["DOTMONETDBFILE"]= dotmonetdb.name
subprocess.check_call(
[
mclient_executable,
"-h", hostname,
"-p", str(port),
"-d", dbname,
"--dump"
],
env=env,
stdout=output_file
)
except Exception, e:
logger.error("Failed to dump: %s" % (e,))
raise
[docs]def dump_pg(hostname, port, dbname, dbuser, dbpass, output_filename):
"""
Dumps a PostgreSQL database in specified output file
"""
pg_dump_executable = "pg_dump"
try:
env = os.environ
env["PGPASSWORD"]= dbpass
subprocess.check_call(
[
pg_dump_executable,
"-h", hostname,
"-p", str(port),
"-U", dbuser,
"-f", output_filename,
dbname
],
env=env
)
except Exception, e:
logger.error("Failed to dump: %s" % (e,))
raise
