T4777: Ability to get logs in machine-readable format

Ability to get logs in JSON format
Possible filter by unit. Options for count lines,
UTC time, facility or logs since boot

1 files changed, 94 insertions, 0 deletions

diff --git a/src/op_mode/log.py b/src/op_mode/log.py
new file mode 100755
index 000000000..b0abd6191
--- /dev/null
+++ b/src/op_mode/log.py
@@ -0,0 +1,94 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2022 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+import json
+import re
+import sys
+import typing
+
+from jinja2 import Template
+
+from vyos.util import rc_cmd
+
+import vyos.opmode
+
+journalctl_command_template = Template("""
+--no-hostname
+--quiet
+
+{% if boot %}
+  --boot
+{% endif %}
+
+{% if count %}
+  --lines={{ count }}
+{% endif %}
+
+{% if reverse %}
+  --reverse
+{% endif %}
+
+{% if since %}
+  --since={{ since }}
+{% endif %}
+
+{% if unit %}
+  --unit={{ unit }}
+{% endif %}
+
+{% if utc %}
+  --utc
+{% endif %}
+
+{% if raw %}
+{# By default show 100 only lines for raw option if count does not set #}
+{# Protection from parsing the full log by default #}
+{%    if not boot %}
+  --lines={{ '' ~ count if count else '100' }}
+{%    endif %}
+  --no-pager
+  --output=json
+{% endif %}
+""")
+
+
+def show(raw: bool,
+         boot: typing.Optional[bool],
+         count: typing.Optional[int],
+         facility: typing.Optional[str],
+         reverse: typing.Optional[bool],
+         utc: typing.Optional[bool],
+         unit: typing.Optional[str]):
+    kwargs = dict(locals())
+
+    journalctl_options = journalctl_command_template.render(kwargs)
+    journalctl_options = re.sub(r'\s+', ' ', journalctl_options)
+    rc, output = rc_cmd(f'journalctl {journalctl_options}')
+    if raw:
+        # Each 'journalctl --output json' line is a separate JSON object
+        # So we should return list of dict
+        return [json.loads(line) for line in output.split('\n')]
+    return output
+
+
+if __name__ == '__main__':
+    try:
+        res = vyos.opmode.run(sys.modules[__name__])
+        if res:
+            print(res)
+    except (ValueError, vyos.opmode.Error) as e:
+        print(e)
+        sys.exit(1)