DevOps  Systems Administration 

Debian

August 29, 2022

 Table of Contents


  1. Debian: The grandaddy of Linux Operating Systems

  2. Amazing Utilities


    1. top

    2. ps

  3. How to find basic hardware information

  4. Keeping software up to date

  5. Updating hostname

  6. OpenVPN

  7. Ubuntu won’t let me in

  8. UNIX/Linux Closing ports

  9. Reclaim Disk Storage

  10. Unknown modifications

  11. Services

  12. unable to resolve host X: Name or service not known

  13. WARNING: apt does not have a stable CLI interface. Use with caution in scripts.

  14. Provide Welcome Message


    1. For Bash Accounts

    2. For Zsh Accounts


      1. How to add attributes on files to secure from deletion

      2. How to unset attribute on Files

      3. How to Secure /etc/passwd and /etc/shadow files

      4. Append data without Modifying existing data on a File

      5. How to Secure Directories

  15. Crons

  16. /etc/resolv.conf

  17. Unable to correct problems, you have held broken packages

  18. Cron logs

  19. SSH Timeouts

  20. Immutable files

  21. Crons not working for victord

  22. Optimizing chmod operations

  23. Failed to resolve “fs-f9777714.efs.ca-central-1.amazonaws.com”

  24. /etc/hosts

  25. stunnel[651]: LOG3[0]: s_connect: s_poll_wait 10.3.5.252:2049: TIMEOUTconnect exceeded No more addresses to connect

  26. Unable to install ZSH

  27. Renaming hosts and hostnames

  28. Background Jobs

  29. Installing Debian Desktop

  30. How to fix a corrupted sudo

  31. Too many open files

  32. Certificate Renewal

  33. Looking up “demo1” failed. You have set the “FQDNLookup” option

  34. [oh-my-zsh] theme ‘puma’ not found

  35. Adding/Deleting Users on a Debian Server


    1. Change Password (passwd)

    2. Create an Account (adduser)

    3. Delete an Account (deluser)

    4. Modify an Account’s properties (usermod)

    5. Change login shell (chsh)

    6. Change user information (chfn)

  36. Disabling user accounts

  37. Enabling user accounts

  38. APT – keeping software packages up-to-date

  39. How to view installed packages

  40. How to search packages

  41. The following packages have unmet dependencies

  42. Uninstalling PHP

  43. Packages can’t be upgraded

  44. Debian: How To Install an Apache, MySQL, and PHP (LAMP) Stack on Debian


    1. Update your Debian

    2. a)     Generate SSH key pair

    3. b)     Install Git

    4. c)      Install oh my zsh

    5. d)     Sync my puma.zsh.theme

    6. e)     Sync my .zshrc

    7. Install Apache 2.4

    8. Install MySQL 8.0

    9. Install PHP 8.0

    10. Configure HTTPS

    11. Install MySQL Workbench

    12. Install Java 11

    13. Install NetBeans

    14. a)          Setup Xdebug

  45. Apache Intro

  46. Apache configtest

  47. Apache helpers


    1. To enable and disable Apache Modules (a2enmod/a2dismod)

    2. To enable and disable Apache Virtual Hosts (a2ensite/a2dissite)

    3. To enable and disable Apache configurations (a2enconf/a2disconf)

    4. Summary of hosts, modules, and configurations that must be enabled

  48. MySQL 8.0 Server

  49. MySQL 8.0 Client

  50. Apache: ELinks: SSL error

  51. Apache: client denied by server configuration: /var/www/html/public/

  52. PHP Fatal error:  Uncaught Error: Undefined constant PDO::MYSQL_ATTR_USE_BUFFERED_QUERY

  53. AH00558: apache2: Could not reliably determine the server’s fully qualified domain name

  54. PHP helpers


    1. To enable and disable Apache Modules (a2enmod/a2dismod)

    2. Summary of modules that must be enabled

  55. Debian not serving HTTPS

  56. PHP curl

  57. Debian 11 – Unable to parse XSD from our BOS ISAPI

  58. Drupal is not working

  59. Ubuntu

  60. Amazing Utilities


    1. top


      1. i

      2. Toogle: Iddle

      3. u

      4. Filter by:  effective

  61. How to find basic hardware information

  62. Keeping software up to date

  63. Updating hostname

  64. OpenVPN

  65. Ubuntu won’t let me in

  66. UNIX/Linux Closing ports

  67. Reclaim Disk Storage

  68. Unknown modifications

  69. Services

  70. Could not get lock /var/lib/dpkg/lock-frontend – open (11: Resource temporarily unavailable)

  71. update : ubuntu > reloading sshd service

  72. Ubuntu: How To Install an Apache, MySQL, and PHP (LAMP) Stack on Ubuntu


    1. Update your Ubuntu

    2. Install Apache 2.4

    3. Install MySQL

    4. Install PHP 7.2

    5. Configure HTTPS


      1. Introduction

  73. Adding/Deleting Users on an Ubuntu Server


    1. Prerequisites

    2. Adding a User

    3. Granting a User Sudo Privileges


      1. Adding the New User to the Sudo Group

      2. Specifying Explicit User Privileges in /etc/sudoers

    4. Testing Your User’s Sudo Privileges

    5. Deleting a User

    6. Conclusion

  74. Switch to root user

  75. Unable to login to CentOS

  76. Creating Groups

  77. Removing user from group

  78. Restring user access with sudo and sudoers

  79. Using SUDO without a password

  80. Using nano as editor with visudo

  81. How to Change the login shell of the user

  82. Downloading files owned by other users

  83. Login without a password


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Written By victord On August 29, 2022