Python module for native access to the systemd facilities. Functionality is separated into a number of modules:
- systemd.journal supports sending of structured messages to the journal and reading journal files,
- systemd.daemon wraps parts of libsystemd useful for writing daemons and socket activation,
- systemd.id128 provides functions for querying machine and boot identifiers and a lists of message identifiers provided by systemd,
- systemd.login wraps parts of libsystemd used to query logged in users and available seats and machines.
This module should be packaged for almost all Linux distributions. Use
On Fedora/RHEL/CentOS
dnf install python-systemd python3-systemd
On Debian/Ubuntu/Mint
apt-get install python-systemd python3-systemd
On openSUSE and SLE
zypper in python-systemd
On CentOS, RHEL, and Fedora with Python 2:
dnf install git python-pip gcc python-devel systemd-devel
pip install git+https://github.com/systemd/python-systemd.git#egg=systemd
On Fedora with Python 3:
dnf install git python3-pip gcc python3-devel systemd-devel
pip3 install git+https://github.com/systemd/python-systemd.git#egg=systemd
On Debian or Ubuntu with Python 2:
apt-get install libsystemd-{journal,daemon,login,id128}-dev gcc python-dev pkg-config
On Debian or Ubuntu with Python 3:
apt-get install libsystemd-{journal,daemon,login,id128}-dev gcc python3-dev pkg-config
The project is also available on pypi as systemd-python
.
Quick example:
from systemd import journal
journal.send('Hello world')
journal.send('Hello, again, world', FIELD2='Greetings!', FIELD3='Guten tag')
journal.send('Binary message', BINARY=b'\xde\xad\xbe\xef')
There is one required argument -- the message, and additional fields can be specified as keyword arguments. Following the journald API, all names are uppercase.
The journald sendv call can also be accessed directly:
from systemd import journal
journal.sendv('MESSAGE=Hello world')
journal.sendv('MESSAGE=Hello, again, world', 'FIELD2=Greetings!',
'FIELD3=Guten tag')
journal.sendv('MESSAGE=Binary message', b'BINARY=\xde\xad\xbe\xef')
The two examples should give the same results in the log.
Reading from the journal is often similar to using the journalctl
utility.
Show all entries since 20 minutes ago (journalctl --since "20 minutes ago"
):
from systemd import journal
from datetime import datetime, timedelta
j = journal.Reader()
j.seek_realtime(datetime.now() - timedelta(minutes=20))
for entry in j:
print(entry['MESSAGE'])
Show entries between two timestamps (journalctl --since "50 minutes ago" --until "10 minutes ago"
):
from systemd import journal
from datetime import datetime, timedelta
j = journal.Reader()
since = datetime.now() - timedelta(minutes=50)
until = datetime.now() - timedelta(minutes=10)
j.seek_realtime(since)
for entry in j:
if entry['__REALTIME_TIMESTAMP'] > until:
break
print(entry['MESSAGE'])
Show explanations of log messages alongside entries (journalctl -x
):
from systemd import journal
j = journal.Reader()
for entry in j:
print("MESSAGE: ", entry['MESSAGE'])
try:
print("CATALOG: ", j.get_catalog())
except:
pass
Show entries by a specific executable (journalctl /usr/bin/vim
):
from systemd import journal
j = journal.Reader()
j.add_match('_EXE=/usr/bin/vim')
for entry in j:
print(entry['MESSAGE'])
- Note: matches can be added from many different fields, for example entries from a specific process ID can be matched with the
_PID
field, and entries from a specific unit (ie.journalctl -u systemd-udevd.service
) can be matched with_SYSTEMD_UNIT
. See all fields available at the systemd.journal-fields docs.
Show kernel ring buffer (journalctl -k
):
from systemd import journal
j = journal.Reader()
j.add_match('_TRANSPORT=kernel')
for entry in j:
print(entry['MESSAGE'])
Read entries in reverse (journalctl _EXE=/usr/bin/vim -r
):
from systemd import journal
class ReverseReader(journal.Reader):
def __next__(self):
ans = self.get_previous()
if ans:
return ans
raise StopIteration()
j = ReverseReader()
j.add_match('_EXE=/usr/bin/vim')
j.seek_tail()
for entry in j:
print(entry['MESSAGE'])
- Unlike the native C version of journald's sd_journal_send(), printf-style substitution is not supported. Perform any substitution using Python's % operator or .format() capabilities first.
- A ValueError is raised if sd_journald_sendv() results in an error. This might happen if there are no arguments or one of them is invalid.
A handler class for the Python logging framework is also provided:
import logging
from systemd import journal
logger = logging.getLogger('custom_logger_name')
logger.addHandler(journal.JournalHandler(SYSLOG_IDENTIFIER='custom_unit_name'))
logger.warning("Some message: %s", 'detail')
This module may be compiled against any version of libsystemd. At compilation time, any functionality that is not available in that version of systemd is disabled, and the resulting binary module will depend on symbols that were available at compilation time. This means that the resulting binary module is compatible with that or any later version of libsystemd. To obtain maximum possible functionality, this module must be compile against suitably recent libsystemd.
Online documentation can be found at freedesktop.org
To build it locally run:
make sphinx-html
Or use any other builder, see man sphinx-build
for a list. The compiled docs will be e.g. in docs/html
.
Quick way to view output with all fields as it comes in:
sudo journalctl -f --output=json
python setup.py build_ext -i
python
>>> from systemd import journal
>>> journal.send("Test")