Trustworthy expert guide to your Synology and UGREEN NAS.

Code: [Select] yay pcsclite-openrc sudo pacman -S pcsc-tools sudo rc-update add pcscd default sudo rc-service pcscd start sudo groupadd pcscd sudo usermod -aG pcscd $USER `pcsc_scan` still doesn't detect it. Yet `lsusb` shows: `Bus 001 Device 012: ID...

Linux administrators are allowed to create "normal user accounts" with a range from 1000 to 60000 uids, where uid 0 is reserved for "root users" and "system users" are allowed uids from 1 to 999.

Turns out it's because I did not create `plugdev` as a system group. I tried Code: [Select] sudo groupdel plugdev sudo groupadd -r plugdev and after rebooting it works.

The Unsung Hero: Deep Dive into groupadd on Ubuntu Introduction Maintaining a...

I am strugling trying use saga processing scripts in headless mode. I have a dockerfile wich build pyqgis environment. But i cant use saga qgis script. My dockerfile: FROM ubuntu:22.04 USER root ENV TZ=America/Cuiaba RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone ENV DEBIAN_FRONTEND=noninteractive RUN apt update && apt upgrade -y RUN apt install -y \ gcc \ libc-dev \ build-essential \ python3-dev \ python3-pip \ vim \ wget \ libreoffice RUN groupadd -g 10004 sysuser_c RUN groupadd -g 1003 psacln RUN groupadd -g 10005 x_project RUN useradd -ms /bin/bash -u 1000 -g 10005 -G sysuser_c,psacln zagros_general RUN mkdir /etc/zagros WORKDIR /etc/zagros COPY ./requirements.txt /etc/zagros/requirements.txt RUN python3 -m pip install --upgrade pip RUN pip install -r /etc/zagros/requirements.txt RUN echo "deb https://qgis.org/ubuntu jammy main" >> /etc/apt/sources.list RUN echo "deb-src https://qgis.org/ubuntu jammy main" >> /etc/apt/sources.list RUN wget -qO - https://qgis.org/downloads/qgis-2022.gpg.key | gpg --no-default-keyring --keyring gnupg-ring:/etc/apt/trusted.gpg.d/qgis-archive.gpg --import RUN chmod a+r /etc/apt/trusted.gpg.d/qgis-archive.gpg RUN apt update RUN apt install -y \ gdal-bin \ libgdal-dev \ xvfb \ python3-qgis \ qgis \ qgis-plugin-grass \ qgis-providers \ saga COPY ./map_proc/. /etc/zagros/ RUN chown -R zagros_general:x_project /etc/zagros RUN chmod -R 774 /etc/zagros RUN pip3 install pymodis RUN apt-get install unoconv RUN unoconv -l -v USER zagros_general Build image - Local machine docker build --no-cache -f Dockerfile -t zagros_general_dock:1.0 . Mount/run container with builted image (need change local path) docker run -it --network host --restart=unless-stopped --name zagros_general --mount type=bind,source=/home/rangeldr04/Documents/GitHub/zagros_general/map_proc,target=/etc/zagros -d zagros_general_dock:1.0 Minimal script to try: import sys from qgis.core import QgsApplication from qgis.analysis import QgsNativeAlgorithms QgsApplication.setPrefixPath("/usr", True) qgs = QgsApplication([], False) qgs.initQgis() sys.path.append('/usr/share/qgis/python/plugins') sys.path.append('/usr/share/qgis/python/plugins/processing') import processing from processing.core.Processing import Processing Processing.initialize() qgs.processingRegistry().addProvider(QgsNativeAlgorithms()) print("\n=== Providers list ===") for provider in QgsApplication.processingRegistry().providers(): print(f"- {provider.id()} ({provider.name()})") # Verifica especificamente o SAGA saga_provider = QgsApplication.processingRegistry().providerById('saga') if saga_provider is None: print("\n❌ SAGA not available.") else: print("\n✅ SAGA available!") print(f"Number of algorithims: {len(saga_provider.algorithms())}") # Encerra o QGIS qgs.exitQgis() Try: Docker exec -it zagros_general /bin/bash QT_QPA_PLATFORM=offscreen python3 test_saga.py

Identity & Access Management (IAM) is the backbone of modern cybersecurity, ensuring only authorized users access specific resources. Let’s break down its core components and practical implementations. Role-Based Access Control (RBAC) RBAC assigns permissions based on predefined roles (e.g., "HR Manager," "DevOps Engineer"). Linux Implementation Create a role-based group sudo groupadd devops Assign a user to the group sudo usermod -aG devops username…

OK, hacked at it some more (thankyou o3 for the assist). Let me know if this gets you rolling… Codex Task #!/usr/bin/env bash set -euo pipefail export DEBIAN_FRONTEND=noninteractive # 1. Install the minimal binaries apt-get update -qq apt-get install -yqq --no-install-recommends \ mysql-server-core-8.0 mysql-client-core-8.0 passwd # 2. Ensure the mysql system account exists if ! id -u mysql >/dev/null 2>&1; then groupadd --system mysql useradd --system --gid mysql --home /nonexistent \ --shell /usr/sbin/nologin mysql fi # 3. Data directories **and** secure-file-priv directory mkdir -p /var/lib/mysql \ /var/lib/mysql-files \ /var/run/mysqld chown -R mysql:mysql /var/lib/mysql /var/lib/mysql-files /var/run/mysqld chmod 750 /var/lib/mysql-files # MySQL expects owner-only access:contentReference[oaicite:1]{index=1} # 4. Initialise and start detached mysqld --initialize-insecure --user=mysql # empty root pwd:contentReference[oaicite:2]{index=2} mysqld --daemonize --user=mysql \ --socket=/var/run/mysqld/mysqld.sock \ --pid-file=/var/run/mysqld/mysqld.pid # 5. Wait until the server is ready until mysqladmin --socket=/var/run/mysqld/mysqld.sock ping --silent; do sleep 1; done #verify # Should print exactly one mysqld line ps -fp $(cat /var/run/mysqld/mysqld.pid) # Fast “is it alive?” check mysqladmin --socket=/var/run/mysqld/mysqld.sock ping # → mysqld is alive # A few server counters & compile flags mysqladmin --socket=/var/run/mysqld/mysqld.sock version

In my second week, I dove into more advanced topics, focusing on user management, file permissions, and file systems. Here’s what I learned: ## 💪 What I Learned This Week **1. User Account Management👥** I have learned how to switch between the users, how to create and manage users and groups using: * `sudo -i` to switch to root user * `su - username` to switch to another user * `useradd` and related flags to create users * `usermod` to modify user attributes * `groupadd` to create groups * `passwd` to set the password for the users **2. Linux File System📂** I took a deeper dive into Linux file systems, focusing on the structure and organisation of files on disk. I explored: * The differences between ext4, XFS and other file systems * How inode works in managing file metadata * The importance of block storage and its role in organizing file data Understanding Linux file systems gave me insight into how data is stored and retrieved on disk, which is essential when working with larger systems or setting up new environments. **3. Linux File Structure📂** I explored the hierarchical layout of the Linux root directory (/). I learned what each central directory is responsible for, including: * /bin – Essential command binaries * /sbin – System binaries for administrative tasks * /usr – User programs and data (Unix System Resources) * /etc – Configuration files for the system * /home – Home directories for all users * /var – Variable files like logs, spool files, etc. * /tmp – Temporary files * /dev, /proc, /sys – Special directories for device files and kernel information Understanding the file structure helped me navigate the system more confidently and organise my work better as a DevOps learner! **4. Types of Files 📚** I understand the various file types in the Linux system and their uses. The file types are: * Regular Files (-) * Directory (d) * Symbolic link (l) * Character Device files (c) * Block Device Files (b) * Named pipe or FIFO files (p) * Socket Files (s) **5. File Permissions🔐** I learned about the importance of file permissions in Linux and how they control who can access and modify files: * The reason to change the permissions: Security 🛡️, Access Control 👨‍💻, Team collaborations 🤝, Functionality ⚙️ * r (read), w (write), and x (execute) permissions for user, group, and others * Using chmod to change file permissions * Symbols like (+) to add and (-) to remove and (a) allow all(everyone) permissions. Understanding file permissions was crucial to managing file access in a multi-user system and protecting sensitive data. **6. User Permissions🧑‍💻** I learned how to manage file and directory permissions for different users and groups. Specifically, I practiced using: * `chown` – to change the owner of a file or directory. * `chgrp` – to change the group ownership of a file or directory. This knowledge is crucial in a multi-user environment to control access, maintain security, and manage collaboration across different teams. **7. Access Control List🛡️** I explored Access Control Lists (ACLs), which provide more granular control over file permissions. I used: * getfacl to view the ACLs of files * setfacl to set permissions for specific users or groups This was a great way to control permissions beyond the basic user/group/others model. ## What’s Next on the Journey? ### Next Steps 🚀 Now that I’ve covered the basics of file permissions, user management, and file systems, I’m ready to dive deeper into the following topics: * Working with .tar files and compressed archives * Mastering regular expressions for efficient text processing * Understanding system processes, logs, and service management * Exploring Linux networking for DevOps tasks * Continuing with hands-on practice on AWS EC2 instances ## 🙌 Final Thoughts My Learning Journey is just beginning, and I’m excited to see where this path takes me as I gain more experience in DevOps. If you're on a similar journey, let’s learn together. 😊 Thanks for reading!

Setting up and managing groups on Linux systems can help when you need to assign specific privileges to particular groups of people.

These are my notes for setting up a “deploy-to-remote-webserver” workflow with ssh and an sftp-only chroot, in case someone might find it useful. Compiled from various bits and pieces around the internet. Setting up SSH Add a group: groupadd -r remote-deploy. This will add a system group Create a folder for authorized keys for users in that group: mkdir -p /etc/ssh/authorized Modify ssh_config AuthorizedKeysFile /etc/ssh/authorized/%u .ssh/authorized_keys Match Group remote-deploy ChrootDirectory %h ForceCommand internal-sftp AllowTcpForwarding no X11Forwarding no PasswordAuthentication no Setting up the chroot jail It is important that the path up until the home folder is owned by root:root. Below that, create a folder that is owned by the user and any supplementary group you might need to access (e.g. www-data) mkdir -p /path/to/chroot/jail/deploy-user chown -R root:root /path/to/chroot/jail/deploy-user chmod -R 755 /path/to/chroot/jail/deploy-user mkdir /path/to/chroot/jail/deploy-user/public chown deploy-user:www-data /path/to/chroot/jail/deploy-user chmod 755 /path/to/chroot/jail/deploy-user Setting up the individual user(s) Add a user to the group created above: useradd -g remote-deploy -M -d /path/to/chroot/jail -s /usr/sbin/nologin deploy-user Generate a new pair of keys and move the public key to the newly configured added keystore ssh-keygen -o deploy-user -t ed25519 mv deploy-user.pub /etc/ssh/authorized/deploy-user Setting up the gitlab pipeline Obtain the host key frm the remote host. To be able to make the variable masked in Gitlab later, it needs to be encoded: ssh-keyscan -q deploy-host.example.com 2>/dev/null | bas64 -w0 Log into your gitlab instance, go to Settings->CI/CD->Variables Click on “Add variable” Set “Masked and Hidden” and “Protect variable” Add a comment like “SSH host key for deploy host” Set name to SSH_HOST_KEY Paste output of the keyscan command Create another variable with the same Settings Add a comment like “SSH private key for deploy user” Set name to SSH_PRIVATE_KEY Paste output of base64 -w0 deploy-user, where deploy-user is the private key generated above Setting up ssh in the pipeline script mkdir ~/.ssh echo -n $SSH_HOST_KEY | base64 -d > ~/.ssh/known_hosts # If necessary, start ssh-agent eval `ssh-agent` echo -n $SSH_PRIVATE_KEY | base64 -d | ssh-add -

Avec ce tutoriel, apprenez à gérer les groupes sous Linux avec la découverte du fichier group et l'utilisation de commandes comme usermod, groupadd et groupmod.