List all Ubuntu servers configured in the inventory (servers.json), with their connection details.

Call this first to discover valid values for the 'server' parameter used by every other ubuntu_* tool.

Args:

• response_format ('markdown' | 'json'): output format (default 'markdown')

Returns: name, host, port, username and description for each configured server. Does not contact the servers, so a listed server is not necessarily reachable right now.

Get a one-shot health overview of an Ubuntu server: hostname, OS release, kernel, uptime, load average, memory usage, disk usage, whether a reboot is required, and any failed systemd services.

This is the best first call when asked "how is server X doing?" — it gathers everything in a single SSH round trip.

Args:

• server (string): server name from the inventory (see ubuntu_list_servers)

• response_format ('markdown' | 'json'): output format (default 'markdown')

Returns: the sections listed above; memory and disk are the raw 'free -h' / 'df -h' tables.

List systemd services on an Ubuntu server, optionally filtered by state.

Args:

• server (string): server name from the inventory (see ubuntu_list_servers)

• state ('all' | 'running' | 'failed'): filter (default 'all')

• limit (number): max services to return, 1-200 (default 50)

• offset (number): skip this many for pagination (default 0)

• response_format ('markdown' | 'json'): output format (default 'markdown')

Returns: unit name, active/sub state, and description per service, with pagination metadata (total, has_more, next_offset).

Example: state='failed' answers "is anything broken on web-01?"

Show detailed status of one systemd service: the full 'systemctl status' output (state, recent log lines, PID, memory) plus whether it is enabled at boot.

Args:

• server (string): server name from the inventory (see ubuntu_list_servers)

• service (string): unit name, e.g. 'nginx' or 'ssh'

Returns: raw status text plus parsed active_state ('active'/'inactive'/'failed') and enabled state ('enabled'/'disabled'/'static').

Error handling: reports if the unit does not exist and suggests ubuntu_list_services to find the right name.

Start, stop, restart, reload, enable, or disable a systemd service. Runs via 'sudo -n', so the server must allow passwordless sudo for the configured user.

Args:

• server (string): server name from the inventory (see ubuntu_list_servers)

• service (string): unit name, e.g. 'nginx'

• action ('start' | 'stop' | 'restart' | 'reload' | 'enable' | 'disable'): what to do

Returns: confirmation plus the service's state after the action.

Error handling: if sudo requires a password the error explains how to configure passwordless sudo. 'reload' fails for services that don't support it — use 'restart' instead.

List pending apt package updates on an Ubuntu server, flag security updates, and report whether a reboot is required. Does NOT install anything.

Args:

• server (string): server name from the inventory (see ubuntu_list_servers)

• refresh_cache (boolean): run 'apt-get update' first via sudo -n for current results (default false)

• limit (number): max packages to list, 1-200 (default 50)

• response_format ('markdown' | 'json'): output format (default 'markdown')

Returns: total pending updates, security update count, reboot-required flag, and per-package old → new versions.

To actually install updates, use ubuntu_run_command with sudo, e.g. command='apt-get upgrade -y' sudo=true — after confirming with the user.

Read recent log lines from an Ubuntu server — either from the systemd journal (journalctl) or from a log file — optionally filtered to lines containing a search string.

Args:

• server (string): server name from the inventory (see ubuntu_list_servers)

• source ('journal' | 'file'): where to read from (default 'journal')

• unit (string, journal only): systemd unit, e.g. 'nginx' — omit for the whole journal

• path (string, file only, required): absolute file path, e.g. '/var/log/syslog'

• lines (number): how many recent lines, 1-1000 (default 100)

• since (string, journal only): time filter like '1 hour ago' or 'today'

• grep (string): only lines containing this text (case-insensitive fixed string)

• use_sudo (boolean): read as root for protected logs (default false)

Returns: the matching log lines as plain text.

Error handling: permission errors suggest use_sudo=true or adding the user to the 'adm'/'systemd-journal' groups.

Examples:

• "errors in nginx logs in the last hour" -> source='journal', unit='nginx', since='1 hour ago', grep='error'

• "last 50 lines of /var/log/auth.log" -> source='file', path='/var/log/auth.log', lines=50

Run an arbitrary shell command on a configured Ubuntu server over SSH and return stdout, stderr, and the exit code.

Prefer the specialized tools when they fit (ubuntu_system_overview, ubuntu_list_services, ubuntu_service_status, ubuntu_check_updates, ubuntu_tail_log) — they produce cleaner output. Use this tool for everything they don't cover.

Args:

• server (string): server name from the inventory (see ubuntu_list_servers)

• command (string): shell command line; pipes and redirects work

• sudo (boolean): run as root via 'sudo -n' — requires passwordless sudo on the server (default false)

• timeout_seconds (number): 1-300, default 30

Returns: exit code plus stdout/stderr text, also available as structured content.

Error handling:

• Unknown server names return the list of valid names.

• A non-zero exit code is NOT a tool error — inspect stderr to understand what the command reported.

• If sudo fails with "a password is required", the server lacks passwordless sudo; the output includes the fix.