Informatics

  1. GitHub GTP_library
  2. GNU/Linux:
    1. TMux
    2. C Language
    3. Process memory
    4. GDB
    5. ffmpeg
    6. Git
    7. Scanner
    8. Software packages
    9. Network hardware and software discovery
    10. SystemD service
    11. QEMU
    12. PDF manipulation tools
    13. Byte Order Mark - 3 invisible characters
    14. Mobile
    15. Processes and /proc filesystem
    16. TCP dump
    17. Graphical Interface
    18. Bluetooth
    19. asciinema
    20. Picking glibc versions at runtime
    21. Executable binary files
    22. Windowing system
  3. C & C++ language:
    1. Numeric limits
    2. Pointers - asterisk and const
    3. Pointers and memory
    4. Time functions
    5. Binary files
  4. System Administration:
    1. General system administration
    2. Network
    3. traceroute
    4. Disk management
    5. Hardware stress testing
    6. Disk error testing
    7. Linux network tuning
    8. MySQL
    9. O.S. update
    10. Other
    11. Socket connection
    12. SSH
    13. SysLog
    14. Unix filesystem
    15. Windows maintenance
    16. Password management
    17. CGroup
    18. iPXE
    19. SELinux
    20. WireGuard
  5. Containers:
    1. Podman / Docker
    2. Kubernetes (K8s)
  6. Cloud:
    1. Amazon Web Services (AWS)
  7. Boot:
    1. UEFI Shell
  8. Security:
    1. Secret management
    2. GPG
    3. YubiKey 5 NFC
    4. Cryptography
    5. 2 Factor Authentication
  9. Aleph GNU/Linux
  10. Test page
  11. Others - migrated from old site
  12. Selena's corner

Posts

  • [2026-06-08 11:57:32 +0000] DNS delegation and cert manager

    So far I have been exposing my services on service-name.k8s.server.paul.grozav.info, and used cert-manager to generate a certificate for each sub-domain, for each service-name. Certificates are issued by Let’s Encrypt, so before issuing a certificate for a specific domain, LE (Let’s Encrypt) needs to verify you are the owner of that domain. And the proof of ownership is done using a challenge. For specific domain certificate requests, an http challenge is enough. LE can make an HTTP request and expect a token in response, to prove you own that domain.

  • [2016-03-24 18:32:14 +0000] Welcome to my site!

    Check out my site: https://paul.grozav.info/ !