Journald MCP Server

Journald MCP Server

An MCP server for accessing systemd journal logs.

Features

• List systemd units from journal logs
• List syslog identifiers from journal logs
• Get datetime of first journal entry
• Filter journal entries by datetime range (since/until)
• Filter by systemd unit or syslog identifier
• Filter by message content (case-insensitive substring matching)
• Natural language datetime parsing (e.g., "2 hours ago", "yesterday at 3pm")
• List units and identifiers within specific time ranges

Installation

# Install dependencies
uv sync

Usage

Run as non-root: Give the user systemd-journal group access usermod -aG systemd-journal $USER

Run the server with:

uv run server.py [OPTIONS]

CLI Options

• --transport: Transport protocol to use (stdio, sse, or streamable-http). Default: stdio
• --port: Port to listen on for HTTP transport (ignored for stdio transport). Default: 3002
• --log-level: Logging level (DEBUG, INFO, WARNING, ERROR, CRITICAL). Default: INFO

Examples

1. Run with stdio transport (default, for MCP clients that communicate via stdin/stdout):

    python server.py

2. Run with HTTP transport on custom port:

    python server.py --transport streamable-http --port 8080

3. Run with SSE transport:

    python server.py --transport sse --port 3000

4. Run with debug logging:

    python server.py --log-level DEBUG

MCP Integration

The server provides the following MCP resources and tools:

Resources

• journal://units: List unique systemd units from journal logs (all accessible time)
• journal://syslog-identifiers: List unique syslog identifiers from journal logs (all accessible time)
• journal://first-entry-datetime: Get the datetime of the first entry in the journal
• journal://units/{since}/{until}: List unique systemd units within a specified time range
• journal://syslog-identifiers/{since}/{until}: List unique syslog identifiers within a specified time range

Tools

• get_journal_entries: Get journal entries with datetime filtering
  • Parameters: since (optional), until (optional), unit (optional), identifier (optional), message_contains (optional), limit (default: 100)
  • Returns: List of entries with timestamp, unit, identifier, and message
  • Example: Get logs from last 2 hours containing "error": since="2 hours ago", message_contains="error"
• get_recent_logs: Get recent journal logs from the last N minutes
  • Parameters: minutes (default: 60), unit (optional), limit (default: 50)
  • Returns: Formatted string of recent log messages

Datetime Input Format

The server uses natural language datetime parsing via the dateparser library. Supported formats include:

• Relative times: "2 hours ago", "yesterday at 3pm", "last week", "now"
• Absolute times: "2024-01-15 14:30", "2024-01-15T14:30:00"
• Mixed: "today at 9am", "tomorrow 3pm"

All times are interpreted as UTC and returned in human-readable format: "YYYY-MM-DD HH:MM:SS UTC"

Development

This project uses:

• Python 3.12+
• MCP FastMCP
• systemd-python for journal access
• Click for CLI interface
• dateparser for natural language datetime parsing

Project Structure

journald-mcp-server/
├── journald_mcp_server/     # Main package
│   ├── __init__.py
│   ├── server.py           # MCP server implementation
│   └── datetime_utils.py   # Datetime parsing and formatting utilities
├── tests/                  # Test suite
│   ├── __init__.py
│   └── test_server.py
├── server.py              # Entry point wrapper
├── pyproject.toml
└── README.md

Running Tests

python -m pytest tests/