Crept scope to include:

* #858: With the "--log-json" flag, log borgmatic's own logs as JSON, not just Borg's.
 * #1204: When verbosity levels differ between console/monitoring/syslog/file, log Borg's output to each one at a different level.
 * When syslog verbosity is enabled, log to systemd's journal (if present) with structured data.

NEWS

@@ -1,6 +1,10 @@
 2.0.14.dev0
  * #485: When running commands (database clients, command hooks, etc.), elevate stderr output to
    borgmatic error logs.
+ * #858: With the "--log-json" flag, log borgmatic's own logs as JSON, not just Borg's.
+ * #1204: When verbosity levels differ between console/monitoring/syslog/file, log Borg's output to
+   each one at a different level.
+ * When syslog verbosity is enabled, log to systemd's journal (if present) with structured data.
 
 2.0.13
  * #1054: Allow the Btrfs hook to create and delete snapshots even when running

borgmatic/borg/break_lock.py

@@ -29,7 +29,7 @@ def break_lock(
         (local_path, 'break-lock')
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
         + (('--debug', '--show-rc') if logger.isEnabledFor(logging.DEBUG) else ())

borgmatic/borg/change_passphrase.py

@@ -32,7 +32,7 @@ def change_passphrase(
         (local_path, 'key', 'change-passphrase')
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
         + (('--debug', '--show-rc') if logger.isEnabledFor(logging.DEBUG) else ())

borgmatic/borg/check.py

@@ -176,7 +176,7 @@ def check_archives(
             + make_check_name_flags(checks_subset, archive_filter_flags)
             + (('--remote-path', remote_path) if remote_path else ())
             + (('--umask', str(umask)) if umask else ())
-            + (('--log-json',) if config.get('log_json') else ())
+            + ('--log-json',)
             + (('--lock-wait', str(lock_wait)) if lock_wait else ())
             + verbosity_flags
             + (('--progress',) if config.get('progress') else ())

borgmatic/borg/compact.py

@@ -31,7 +31,7 @@ def compact_segments(
         (local_path, 'compact')
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (('--progress',) if config.get('progress') else ())
         + (('--cleanup-commits',) if cleanup_commits else ())

borgmatic/borg/create.py

@@ -217,7 +217,7 @@ def make_base_create_command(
         + (('--files-cache', files_cache) if files_cache else ())
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (
             ('--list', '--filter', list_filter_flags)

borgmatic/borg/delete.py

@@ -38,7 +38,7 @@ def make_delete_command(
         + borgmatic.borg.flags.make_flags('dry-run', global_arguments.dry_run)
         + borgmatic.borg.flags.make_flags('remote-path', remote_path)
         + borgmatic.borg.flags.make_flags('umask', config.get('umask'))
-        + borgmatic.borg.flags.make_flags('log-json', config.get('log_json'))
+        + ('--log-json',)
         + borgmatic.borg.flags.make_flags('lock-wait', config.get('lock_wait'))
         + borgmatic.borg.flags.make_flags('list', config.get('list_details'))
         + (

borgmatic/borg/export_key.py

@@ -48,7 +48,7 @@ def export_key(
         (local_path, 'key', 'export')
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
         + (('--debug', '--show-rc') if logger.isEnabledFor(logging.DEBUG) else ())

borgmatic/borg/export_tar.py

@@ -41,7 +41,7 @@ def export_tar_archive(
         (local_path, 'export-tar')
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
         + (('--list',) if config.get('list_details') else ())

borgmatic/borg/extract.py

@@ -49,7 +49,7 @@ def extract_last_archive_dry_run(
     full_extract_command = (
         (local_path, 'extract', '--dry-run')
         + (('--remote-path', remote_path) if remote_path else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + verbosity_flags
         + list_flag
@@ -127,7 +127,7 @@ def extract_archive(
         + (('--remote-path', remote_path) if remote_path else ())
         + numeric_ids_flags
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
         + (('--debug', '--list', '--show-rc') if logger.isEnabledFor(logging.DEBUG) else ())

borgmatic/borg/import_key.py

@@ -44,7 +44,7 @@ def import_key(
         (local_path, 'key', 'import')
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
         + (('--debug', '--show-rc') if logger.isEnabledFor(logging.DEBUG) else ())

borgmatic/borg/info.py

@@ -40,7 +40,7 @@ def make_info_command(
         )
         + flags.make_flags('remote-path', remote_path)
         + flags.make_flags('umask', config.get('umask'))
-        + flags.make_flags('log-json', config.get('log_json'))
+        + ('--log-json',)
         + flags.make_flags('lock-wait', config.get('lock_wait'))
         + (
             (

borgmatic/borg/list.py

@@ -53,7 +53,7 @@ def make_list_command(
         )
         + flags.make_flags('remote-path', remote_path)
         + flags.make_flags('umask', config.get('umask'))
-        + flags.make_flags('log-json', config.get('log_json'))
+        + ('--log-json',)
         + flags.make_flags('lock-wait', config.get('lock_wait'))
         + flags.make_flags('format', list_arguments.format or config.get('file_list_format'))
         + flags.make_flags_from_arguments(list_arguments, excludes=MAKE_FLAGS_EXCLUDES)

borgmatic/borg/mount.py

@@ -32,7 +32,7 @@ def mount_archive(
         (local_path, 'mount')
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
         + (('--debug', '--show-rc') if logger.isEnabledFor(logging.DEBUG) else ())

borgmatic/borg/prune.py

@@ -74,7 +74,7 @@ def prune_archives(
         + make_prune_flags(config, prune_arguments, local_borg_version)
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (
             ('--stats',)

borgmatic/borg/recreate.py

@@ -46,7 +46,7 @@ def recreate_archive(
     recreate_command = (
         (local_path, 'recreate')
         + (('--remote-path', remote_path) if remote_path else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait is not None else ())
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
         + (('--debug', '--show-rc') if logger.isEnabledFor(logging.DEBUG) else ())

borgmatic/borg/rename.py

@@ -25,7 +25,7 @@ def make_rename_command(
         + borgmatic.borg.flags.make_flags('dry-run', dry_run)
         + borgmatic.borg.flags.make_flags('remote-path', remote_path)
         + borgmatic.borg.flags.make_flags('umask', config.get('umask'))
-        + borgmatic.borg.flags.make_flags('log-json', config.get('log_json'))
+        + ('--log-json',)
         + borgmatic.borg.flags.make_flags('lock-wait', config.get('lock_wait'))
         + (tuple(shlex.split(extra_borg_options)) if extra_borg_options else ())
         + borgmatic.borg.flags.make_repository_archive_flags(

borgmatic/borg/repo_create.py

@@ -89,7 +89,7 @@ def create_repository(
         + (('--make-parent-dirs',) if make_parent_directories else ())
         + (('--info',) if logger.getEffectiveLevel() == logging.INFO else ())
         + (('--debug',) if logger.isEnabledFor(logging.DEBUG) else ())
-        + (('--log-json',) if config.get('log_json') else ())
+        + ('--log-json',)
         + (('--lock-wait', str(lock_wait)) if lock_wait else ())
         + (('--remote-path', remote_path) if remote_path else ())
         + (('--umask', str(umask)) if umask else ())

borgmatic/borg/repo_delete.py

@@ -51,7 +51,7 @@ def make_repo_delete_command(
         + borgmatic.borg.flags.make_flags('dry-run', global_arguments.dry_run)
         + borgmatic.borg.flags.make_flags('remote-path', remote_path)
         + borgmatic.borg.flags.make_flags('umask', config.get('umask'))
-        + borgmatic.borg.flags.make_flags('log-json', config.get('log_json'))
+        + ('--log-json',)
         + borgmatic.borg.flags.make_flags('lock-wait', config.get('lock_wait'))
         + borgmatic.borg.flags.make_flags('list', config.get('list_details'))
         + (

borgmatic/borg/repo_info.py

@@ -49,7 +49,7 @@ def display_repository_info(
         )
         + flags.make_flags('remote-path', remote_path)
         + flags.make_flags('umask', config.get('umask'))
-        + flags.make_flags('log-json', config.get('log_json'))
+        + ('--log-json',)
         + flags.make_flags('lock-wait', lock_wait)
         + (('--json',) if repo_info_arguments.json else ())
         + (tuple(shlex.split(extra_borg_options)) if extra_borg_options else ())

borgmatic/borg/repo_list.py

@@ -77,7 +77,7 @@ def get_latest_archive(
         ),
         *flags.make_flags('remote-path', remote_path),
         *flags.make_flags('umask', config.get('umask')),
-        *flags.make_flags('log-json', config.get('log_json')),
+        + ('--log-json',)
         *flags.make_flags('lock-wait', config.get('lock_wait')),
         *(
             flags.make_flags('consider-checkpoints', consider_checkpoints)
@@ -153,7 +153,7 @@ def make_repo_list_command(
         )
         + flags.make_flags('remote-path', remote_path)
         + flags.make_flags('umask', config.get('umask'))
-        + flags.make_flags('log-json', config.get('log_json'))
+        + ('--log-json',)
         + flags.make_flags('lock-wait', config.get('lock_wait'))
         + (
             (

borgmatic/borg/transfer.py

@@ -33,7 +33,7 @@ def transfer_archives(
         + (('--debug', '--show-rc') if logger.isEnabledFor(logging.DEBUG) else ())
         + flags.make_flags('remote-path', remote_path)
         + flags.make_flags('umask', config.get('umask'))
-        + flags.make_flags('log-json', config.get('log_json'))
+        + ('--log-json',)
         + flags.make_flags('lock-wait', config.get('lock_wait'))
         + flags.make_flags('progress', config.get('progress'))
         + (

borgmatic/commands/borgmatic.py

@@ -660,6 +660,7 @@ def load_configurations(config_filenames, arguments, overrides=None, resolve_env
                         levelno=logging.DEBUG,
                         levelname='DEBUG',
                         msg=f'{config_filename}: Loading configuration file',
+                        name=logger.name,
                     ),
                 ),
             ],
@@ -682,6 +683,7 @@ def load_configurations(config_filenames, arguments, overrides=None, resolve_env
                             levelno=logging.CRITICAL,
                             levelname='CRITICAL',
                             msg=f'{config_filename}: Insufficient permissions to read configuration file',
+                            name=logger.name,
                         ),
                     ),
                 ],
@@ -694,10 +696,11 @@ def load_configurations(config_filenames, arguments, overrides=None, resolve_env
                             levelno=logging.CRITICAL,
                             levelname='CRITICAL',
                             msg=f'{config_filename}: Error parsing configuration file',
+                            name=logger.name,
                         ),
                     ),
                     logging.makeLogRecord(
-                        dict(levelno=logging.CRITICAL, levelname='CRITICAL', msg=str(error)),
+                        dict(levelno=logging.CRITICAL, levelname='CRITICAL', msg=str(error), name=logger.name),
                     ),
                 ],
             )
@@ -710,7 +713,7 @@ def log_record(suppress_log=False, **kwargs):
     Create a log record based on the given makeLogRecord() arguments, one of which must be
     named "levelno". Log the record (unless suppress log is set) and return it.
     '''
-    record = logging.makeLogRecord(kwargs)
+    record = logging.makeLogRecord(dict(kwargs, name=logger.name))
     if suppress_log:
         return record
 
@@ -823,6 +826,7 @@ def collect_highlander_action_summary_logs(configs, arguments, configuration_par
                     levelno=logging.ANSWER,
                     levelname='ANSWER',
                     msg='Bootstrap successful',
+                    name=logger.name,
                 ),
             )
         except (
@@ -845,6 +849,7 @@ def collect_highlander_action_summary_logs(configs, arguments, configuration_par
                     levelno=logging.ANSWER,
                     levelname='ANSWER',
                     msg='Generate successful',
+                    name=logger.name,
                 ),
             )
         except (
@@ -863,6 +868,7 @@ def collect_highlander_action_summary_logs(configs, arguments, configuration_par
                     levelno=logging.CRITICAL,
                     levelname='CRITICAL',
                     msg='Configuration validation failed',
+                    name=logger.name,
                 ),
             )
 
@@ -876,6 +882,7 @@ def collect_highlander_action_summary_logs(configs, arguments, configuration_par
                     levelno=logging.ANSWER,
                     levelname='ANSWER',
                     msg='All configuration files are valid',
+                    name=logger.name,
                 ),
             )
         except (
@@ -968,6 +975,7 @@ def collect_configuration_run_summary_logs(configs, config_paths, arguments, log
                         levelno=logging.INFO,
                         levelname='INFO',
                         msg=f'{config_filename}: Successfully ran configuration file',
+                        name=logger.name,
                     ),
                 )
                 if results:
@@ -1126,6 +1134,7 @@ def main(extra_summary_logs=()):  # pragma: no cover
         getattr(sub_arguments, 'json', False) for sub_arguments in arguments.values()
     )
     log_file_path = get_singular_option_value(configs, 'log_file')
+    log_json = get_singular_option_value(configs, 'log_json')
 
     try:
         configure_logging(
@@ -1135,7 +1144,8 @@ def main(extra_summary_logs=()):  # pragma: no cover
             verbosity_to_log_level(get_verbosity(configs, 'monitoring_verbosity')),
             log_file_path,
             get_singular_option_value(configs, 'log_file_format'),
-            color_enabled=should_do_markup(configs, any_json_flags),
+            log_json,
+            color_enabled=should_do_markup(configs, any_json_flags or log_json),
         )
     except (FileNotFoundError, PermissionError) as error:
         configure_logging(logging.CRITICAL)
@@ -1165,7 +1175,7 @@ def main(extra_summary_logs=()):  # pragma: no cover
     )
     summary_logs_max_level = max(log.levelno for log in summary_logs)
 
-    for message in ('', 'summary:'):
+    for message in ('summary:',) if log_json else ('', 'summary:'):
         log_record(
             levelno=summary_logs_max_level,
             levelname=logging.getLevelName(summary_logs_max_level),

borgmatic/execute.py

@@ -1,5 +1,7 @@
 import collections
+import contextlib
 import enum
+import json
 import logging
 import select
 import subprocess
@@ -89,44 +91,62 @@ def output_buffers_for_process(process, exclude_stdouts):
     )
 
 
-def determine_log_level(output_log_level, came_from_stderr, borg_local_path, command, line):
+def borg_log_data_to_log_record(log_data):
     '''
-    Given the requested output log level, whether the this log line came from stderr, the Borg local
-    path, the command as a sequence, and the line to be logged, return the log level that should be
-    used.
-
-    Borg happens to log everything to stderr (except JSON output), so if this is a Borg command, use
-    the requested log level regardless of whether this is for stdout or stderr. (Otherwise, all Borg
-    logs would show up at ERROR level even if there's no error!)
-
-    But for other commands, elevate stderr logs to ERROR while using the requested log level for
-    stdout. The one exception is if the log came from stderr and the string "warning" appears at the
-    start of the log line. In that case, just elevate the log level to a WARN.
+    Given a log data dict for a single Borg log entry, return it converted to a logging.LogRecord
+    instance.
     '''
+    return logging.makeLogRecord(
+        dict(
+            levelno=logging._nameToLevel.get(log_data.get('levelname')),
+            created=log_data.get('time'),
+            msg=log_data.get('message'),
+            levelname=log_data.get('levelname'),
+            name=log_data.get('name'),
+        )
+    )
+
+
+def log_line(last_lines, captured_output, line, default_log_level, came_from_stderr, borg_local_path, command):
+    '''
+    Given a rolling list of last lines, a list of captured output, the line to be logged, a default
+    log level, whether the this log line came from stderr, the Borg local path, and the command as a
+    sequence, append the line to the last lines and (if the log level is None) the captured output.
+    Then log the line at the requested log level.
+
+    If the command being run is Borg, and the log line is JSON-formatted log data, then grab the log
+    level from it and log the parsed JSON to be consumed later by a Python logging.Formatter.
+
+    But for non-Borg commands, elevate stderr-sourced logs to ERROR. The one exception is if the log
+    came from stderr and the string "warning:" appears at the start of the log line. In that case,
+    just elevate the log level to a WARN.
+    '''
+    log_message = line
+    log_level = default_log_level
+    line_data = None
+
     if borg_local_path and command[0] == borg_local_path:
-        return output_log_level
+        with contextlib.suppress(json.JSONDecodeError, TypeError, KeyError):
+            line_data = json.loads(line)
+            borg_level_name = line_data['levelname']
+            log_message = line_data['message']
+            log_level = logging._nameToLevel.get(borg_level_name)
+    elif came_from_stderr:
+        log_level = logging.WARN if line.lower().startswith('warning:') else logging.ERROR
 
-    if came_from_stderr:
-        return logging.WARN if line.lower().startswith('warning:') else logging.ERROR
-
-    return output_log_level
-
-
-def append_last_lines(last_lines, captured_output, line, log_level):
-    '''
-    Given a rolling list of last lines, a list of captured output, a line to append, and an output
-    log level, append the line to the last lines and (if necessary) the captured output. Then log
-    the line at the requested log level.
-    '''
-    last_lines.append(line)
+    last_lines.append(log_message)
 
     if len(last_lines) > ERROR_OUTPUT_MAX_LINE_COUNT:
         last_lines.pop(0)
 
     if log_level is None:
-        captured_output.append(line)
+        captured_output.append(log_message)
+        return
+
+    if line_data:
+        logger.handle(borg_log_data_to_log_record(line_data))
     else:
-        logger.log(log_level, line)
+        logger.log(log_level, log_message)
 
 
 def log_outputs(processes, exclude_stdouts, output_log_level, borg_local_path, borg_exit_codes):  # noqa: PLR0912
@@ -190,17 +210,14 @@ def log_outputs(processes, exclude_stdouts, output_log_level, borg_local_path, b
 
                     # Keep the last few lines of output in case the process errors, and we need the
                     # output for the exception below.
-                    append_last_lines(
-                        buffer_last_lines[ready_buffer],
-                        captured_outputs[ready_process],
-                        line,
-                        determine_log_level(
-                            output_log_level,
-                            (ready_buffer == ready_process.stderr),
-                            borg_local_path,
-                            command,
-                            line,
-                        ),
+                    log_line(
+                        last_lines=buffer_last_lines[ready_buffer],
+                        captured_output=captured_outputs[ready_process],
+                        line=line,
+                        default_log_level=output_log_level,
+                        came_from_stderr=(ready_buffer == ready_process.stderr),
+                        borg_local_path=borg_local_path,
+                        command=command,
                     )
 
         if not still_running:
@@ -231,17 +248,14 @@ def log_outputs(processes, exclude_stdouts, output_log_level, borg_local_path, b
                         if not line:
                             break
 
-                        append_last_lines(
-                            last_lines,
-                            captured_outputs[process],
-                            line,
-                            determine_log_level(
-                                output_log_level,
-                                (output_buffer == process.stderr),
-                                borg_local_path,
-                                command,
-                                line,
-                            ),
+                        log_line(
+                            last_lines=last_lines,
+                            captured_output=captured_outputs[process],
+                            line=line,
+                            default_log_level=output_log_level,
+                            came_from_stderr=(output_buffer == process.stderr),
+                            borg_local_path=borg_local_path,
+                            command=command,
                         )
 
                 if len(last_lines) == ERROR_OUTPUT_MAX_LINE_COUNT:

borgmatic/logger.py

@@ -1,7 +1,9 @@
 import enum
+import json
 import logging
 import logging.handlers
 import os
+import socket
 import sys
 
 
@@ -85,6 +87,54 @@ class Multi_stream_handler(logging.Handler):
             handler.setLevel(level)
 
 
+DEFAULT_JOURNALD_PRIORITY = 6
+
+
+class JournaldHandler(logging.Handler):
+    def __init__(self, journald_socket_path):
+        super().__init__()
+
+        add_custom_log_levels()
+
+        self.journald_socket_path = journald_socket_path
+        self.log_level_to_journald_priority = {
+            logging.ERROR: 3,
+            logging.WARNING: 4,
+            logging.ANSWER: 5,
+            logging.INFO: 6,
+            logging.DEBUG: 7,
+        }
+
+    def emit(self, record):
+        sock = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
+
+        try:
+            message_parts = []
+            entry = dict(
+                LOGGER_NAME=record.name,
+                MESSAGE=record.getMessage(),
+                PRIORITY=self.log_level_to_journald_priority.get(record.levelno, DEFAULT_JOURNALD_PRIORITY),
+                SYSLOG_IDENTIFIER='borgmatic',
+                SYSLOG_PID=os.getpid(),
+                UNIT=record.name,
+            )
+
+            for key, value in entry.items():
+                key = key.upper().encode('utf-8')
+                value = str(value).encode('utf-8')
+
+                # Multi-line and single-line values use different formats on the wire.
+                if b'\n' in value:
+                    message_parts.extend((key, b'\n'))
+                    message_parts.extend((len(value).to_bytes(8, 'little'), value, b'\n'))
+                else:
+                    message_parts.extend((key, b'=', value, b'\n'))
+
+            sock.sendto(b''.join(message_parts), self.journald_socket_path)
+        finally:
+            sock.close()
+
+
 class Log_prefix_formatter(logging.Formatter):
     def __init__(self, fmt='{prefix}{message}', *args, style='{', **kwargs):
         self.prefix = None
@@ -97,6 +147,31 @@ class Log_prefix_formatter(logging.Formatter):
         return super().format(record)
 
 
+def log_record_to_json(record, **extra):
+    '''
+    Given a logging.LogRecord, return it as a JSON-encoded string containing relevant attributes.
+    Add in any extra kwargs that are given.
+    '''
+    return json.dumps(
+        dict(
+            type='log_message',
+            time=record.created,
+            message=record.getMessage(),
+            levelname=record.levelname,
+            name=record.name,
+            **extra,
+        )
+    )
+
+
+class Json_formatter(logging.Formatter):
+    def __init__(self, fmt='{message}', *args, style='{', **kwargs):
+        super().__init__(*args, fmt=fmt, style=style, **kwargs)
+
+    def format(self, record):
+        return log_record_to_json(record)
+
+
 class Color(enum.Enum):
     RESET = 0
     RED = 31
@@ -321,6 +396,10 @@ def flush_delayed_logging(target_handlers):
         root_logger.removeHandler(delayed_handler)
 
 
+JOURNALD_SOCKET_PATH = '/run/systemd/journal/socket'
+SYSLOG_PATHS = ('/dev/log', '/var/run/syslog', '/var/run/log')
+
+
 def configure_logging(
     console_log_level,
     syslog_log_level=None,
@@ -328,6 +407,7 @@ def configure_logging(
     monitoring_log_level=None,
     log_file=None,
     log_file_format=None,
+    log_json=False,
     color_enabled=True,
 ):
     '''
@@ -364,7 +444,9 @@ def configure_logging(
         },
     )
 
-    if color_enabled:
+    if log_json:
+        console_handler.setFormatter(Json_formatter())
+    elif color_enabled:
         console_handler.setFormatter(Console_color_formatter())
     else:
         console_handler.setFormatter(Log_prefix_formatter())
@@ -373,28 +455,34 @@ def configure_logging(
     handlers = [console_handler]
 
     if syslog_log_level != logging.DISABLED:
-        syslog_path = None
-
-        if os.path.exists('/dev/log'):
-            syslog_path = '/dev/log'
-        elif os.path.exists('/var/run/syslog'):
-            syslog_path = '/var/run/syslog'
-        elif os.path.exists('/var/run/log'):
-            syslog_path = '/var/run/log'
-
-        if syslog_path:
-            syslog_handler = logging.handlers.SysLogHandler(address=syslog_path)
-            syslog_handler.setFormatter(
-                Log_prefix_formatter(
-                    'borgmatic: {levelname} {prefix}{message}',
+        if os.path.exists(JOURNALD_SOCKET_PATH):
+            journald_handler = JournaldHandler(JOURNALD_SOCKET_PATH)
+            journald_handler.setLevel(syslog_log_level)
+            handlers.append(journald_handler)
+        else:
+            syslog_path = next(
+                (
+                    path
+                    for path in SYSLOG_PATHS
+                    if os.path.exists(path)
                 ),
+                None,
             )
-            syslog_handler.setLevel(syslog_log_level)
-            handlers.append(syslog_handler)
+
+            if syslog_path:
+                syslog_handler = logging.handlers.SysLogHandler(address=syslog_path)
+                syslog_handler.setFormatter(
+                    Log_prefix_formatter(
+                        'borgmatic: {levelname} {prefix}{message}',
+                    ),
+                )
+                syslog_handler.setLevel(syslog_log_level)
+                handlers.append(syslog_handler)
 
     if log_file and log_file_log_level != logging.DISABLED:
         file_handler = logging.handlers.WatchedFileHandler(log_file)
         file_handler.setFormatter(
+            Json_formatter() if log_json else
             Log_prefix_formatter(
                 log_file_format or '[{asctime}] {levelname}: {prefix}{message}',
             ),