linux-admin

Purpose

This skill provides tools for administering Ubuntu Server 24.04 LTS, focusing on package management with apt, user account creation and modification, disk and filesystem operations, kernel parameter tuning via sysctl, and log management.

When to Use

Use this skill for server setup, maintenance, or troubleshooting on Ubuntu 24.04, such as deploying applications, securing user access, optimizing system performance, or analyzing logs in production environments.

Key Capabilities

Package Management (apt): Update repositories, install/uninstall packages, and manage dependencies using
```
apt
```
with flags like
```
-y
```
for non-interactive mode.
User Management: Create, modify, or delete users with commands like
```
useradd
```
,
```
usermod
```
, and
```
userdel
```
, including options for home directories and shells.
Disk/Filesystem: Partition disks with
```
fdisk
```
, format filesystems using
```
mkfs
```
, and mount/unmount with
```
mount
```
and
```
umount
```
, supporting formats like ext4.
Sysctl: Adjust kernel parameters dynamically, e.g., for networking or security, by editing
```
/etc/sysctl.conf
```
and applying with
```
sysctl -p
```
.
Log Management: Query and filter system logs using
```
journalctl
```
, with options like
```
--since
```
for time-based searches and persistent storage in
```
/var/log
```
.

Usage Patterns

Invoke this skill via shell commands in scripts or AI prompts. Always prefix commands with

sudo

for root privileges. Example 1: To install a package and add a user, use a sequence like:

sudo apt update; sudo apt install nginx -y; sudo useradd webuser -m

. Example 2: For disk management and log check, run:

sudo fdisk /dev/sda; sudo mkfs.ext4 /dev/sda1; sudo mount /dev/sda1 /mnt; sudo journalctl -u nginx --since "1 hour ago"

Common Commands/API

Apt Example: Update and install a package:
```
sudo apt update
sudo apt install vim -y
```

User Management Example: Add a user with home directory:

sudo useradd newuser -m -s /bin/bash
sudo passwd newuser

Disk/Filesystem Example: Create and mount a filesystem:

sudo fdisk -l /dev/sdb  # List partitions
sudo mkfs.ext4 /dev/sdb1
sudo mount /dev/sdb1 /mnt/data

Sysctl Example: Set a kernel parameter:

echo "net.core.somaxconn=1024" | sudo tee -a /etc/sysctl.conf
sudo sysctl -p

Log Management Example: Filter logs for a service:

sudo journalctl -u apache2 --since yesterday
sudo journalctl -p err  # Show only errors

Integration Notes

Run commands in a Bash environment on Ubuntu 24.04. For remote access, use SSH; no API keys required for core functions, but if integrating with external tools like monitoring APIs, set env vars like

$LINUX_API_KEY

for authentication. Ensure the AI agent prefixes commands with

sudo

and handles output parsing, e.g., check for

apt

success via exit codes.

Error Handling

Check command exit codes immediately; for example, after

sudo apt install package

, verify with

if [ $? -ne 0 ]; then echo "Installation failed"; fi

. Parse errors from stdout/stderr, e.g.,

apt

errors like "E: Unable to locate package" indicate missing repos—run

sudo apt update

first. For sysctl, if a parameter fails, check

/var/log/syslog

for details. Use

try-catch

in scripts:

command_output=$(sudo apt update 2>&1)
if [[ $command_output == *"ERROR"* ]]; then echo "Handle error"; fi

Graph Relationships

Related to: linux cluster skills like "networking" for firewall integration.
Depends on: None directly, but assumes base Ubuntu setup.
Conflicts with: None specified.

linux-admin

NPX Install

Tags

SKILL.md Content

linux-admin

Purpose

When to Use

Key Capabilities

Usage Patterns

Common Commands/API

Integration Notes

Error Handling

Graph Relationships