def external_program_check(to_check=frozenset([PSQL_BIN, LZOP_BIN, PV_BIN])):
"""
Validates the existence and basic working-ness of other programs
Implemented because it is easy to get confusing error output when
one does not install a dependency because of the fork-worker model
that is both necessary for throughput and makes more obscure the
cause of failures. This is intended to be a time and frustration
saving measure. This problem has confused The Author in practice
when switching rapidly between machines.
"""
could_not_run = []
error_msgs = []
def psql_err_handler(popen):
assert popen.returncode != 0
error_msgs.append(
textwrap.fill("Could not get a connection to the database: " "note that superuser access is required")
)
# Bogus error message that is re-caught and re-raised
raise EnvironmentError("INTERNAL: Had problems running psql " "from external_program_check")
with open(os.devnull, "wb") as nullf:
for program in to_check:
try:
if program is PSQL_BIN:
psql_csv_run("SELECT 1", error_handler=psql_err_handler)
else:
if program is PV_BIN:
extra_args = ["--quiet"]
else:
extra_args = []
proc = popen_sp([program] + extra_args, stdout=nullf, stderr=nullf, stdin=subprocess.PIPE)
# Close stdin for processes that default to
# reading from the pipe; the programs WAL-E uses
# of this kind will terminate in this case.
proc.stdin.close()
proc.wait()
except EnvironmentError:
could_not_run.append(program)
if could_not_run:
error_msgs.append("Could not run the following programs, are they installed? " + ", ".join(could_not_run))
if error_msgs:
raise UserException("could not run one or more external programs WAL-E depends upon", "\n".join(error_msgs))
return None
def external_program_check(to_check=frozenset([PSQL_BIN, LZOP_BIN, PV_BIN])):
"""
Validates the existence and basic working-ness of other programs
Implemented because it is easy to get confusing error output when
one does not install a dependency because of the fork-worker model
that is both necessary for throughput and makes more obscure the
cause of failures. This is intended to be a time and frustration
saving measure. This problem has confused The Author in practice
when switching rapidly between machines.
"""
could_not_run = []
error_msgs = []
def psql_err_handler(popen):
assert popen.returncode != 0
error_msgs.append(
textwrap.fill('Could not get a connection to the database: '
'note that superuser access is required'))
# Bogus error message that is re-caught and re-raised
raise EnvironmentError('INTERNAL: Had problems running psql '
'from external_program_check')
with open(os.devnull, 'wb') as nullf:
for program in to_check:
try:
if program is PSQL_BIN:
psql_csv_run('SELECT 1', error_handler=psql_err_handler)
else:
if program is PV_BIN:
extra_args = ['--quiet']
else:
extra_args = []
proc = popen_sp([program] + extra_args,
stdout=nullf,
stderr=nullf,
stdin=subprocess.PIPE)
# Close stdin for processes that default to
# reading from the pipe; the programs WAL-E uses
# of this kind will terminate in this case.
proc.stdin.close()
proc.wait()
except EnvironmentError:
could_not_run.append(program)
if could_not_run:
error_msgs.append(
'Could not run the following programs, are they installed? ' +
', '.join(could_not_run))
if error_msgs:
raise UserException(
'could not run one or more external programs WAL-E depends upon',
'\n'.join(error_msgs))
return None
