OCI landing zone DEMO

  • Grateful for the Opportunity – Excited About the OCI Journey Ahead

    I would like to take a moment to sincerely thank the hiring team for the opportunity to interview for this Oracle Cloud Infrastructure (OCI) role.

    The chance to engage in a conversation around OCI architecture, infrastructure automation, and cloud best practices is something I genuinely value.

    Throughout my experience working with cloud infrastructure, automation, and DevOps practices, I have developed a strong appreciation for well-designed enterprise architectures.

    What excites me most about this opportunity is the focus on building robust OCI landing zones.

    I am looking forward to the interview discussion and, hopefully, the opportunity to contribute to the team’s success. Regardless of the outcome, I truly appreciate the time and consideration from the team.

    Thank you again for this opportunity—I am genuinely excited about what lies ahead.

  • Infrastructure behind the website

    Below is a ASCII architecture diagram of:

    • OCI CIS Landing Zone
    • DRG as hub
    • Multiple VCNs (3-tier landing zone)
    • My WordPress setup (LB → App VCN → VM → DB)

    Made via https://github.com/oci-landing-zones/terraform-oci-core-landingzone and OCI Resource Manager.

                                   
                                        INTERNET
                                            |
                                            |
                             +--------------------------------+
                             |  DNS (DuckDNS)                |
                             | constantininterview.duckdns.org
                             +----------------+---------------+
                                              |
                                              | HTTPS (443) / HTTP (80)
                                              v
                             +--------------------------------+
                             | OCI PUBLIC LOAD BALANCER       |
                             |--------------------------------|
                             | - HTTPS                        |
                             | - HTTP → HTTPS redirect        |
                             | - Listeners: 80 / 443          |
                             +----------------+---------------+
                                              |
                                              |
                          =====================================================
                          |          OCI CIS LANDING ZONE                     |
                          |                                                   |
                          =====================================================
                                              |
                                     +--------+--------+
                                     |       DRG        |
                                     |   (Hub Router)   |
                                     +--------+--------+
                                              |
            -------------------------------------------------------------------------------
            |                     |                     |                      |
            |                     |                     |                      |
            v                     v                     v                      v
    
    +------------------+ +------------------+ +------------------+ +------------------+
    | APP VCN 1        | | APP VCN 2        | | APP VCN 3        | | BASTION VCN      |
    | 192.168.0.0/24   | | 192.168.1.0/24   | | 192.168.2.0/24   | | 10.0.0.0/24      |
    | WordPress stack  | | future workload  | | future workload  | | admin access     |
    +--------+---------+ +--------+---------+ +--------+---------+ +--------+---------+
             |                    |                    |                    |
             |                    |                    |                    |
             v                    v                    v                    v
    
    --------------------------- APP VCN 1 (WORDPRESS) ----------------------------
    
       +--------------------------------------------------------------+
       | PUBLIC SUBNET (WEB TIER)                                    |
       | - Load Balancer backend                                      |
       +----------------------------+---------------------------------+
                                    |
                                    v
       +--------------------------------------------------------------+
       | PRIVATE SUBNET (APP TIER)                                   |
       |                                                              |
       | WORDPRESS VM (Ubuntu)                                        |
       | - Apache                                                     |
       | - PHP                                                        |
       | - WordPress CMS                                              |
       | - Certbot (Let’s Encrypt)                                    |
       +----------------------------+---------------------------------+
                                    |
                                    v
       +--------------------------------------------------------------+
       | PRIVATE SUBNET (DB TIER)                                    |
       |                                                              |
       | MariaDB / MySQL                                              |
       | - WordPress database                                         |
       | - Not publicly accessible                                    |
       +--------------------------------------------------------------+
    
    
    --------------------------- BASTION VCN ----------------------------
    
       +--------------------------------------------------------------+
       | PUBLIC SUBNET                                                |
       |                                                              |
       | Bastion Host (Jump Server)                                   |
       | - SSH access point                                           |
       | - No direct public access to app/db                          |
       +----------------------------+---------------------------------+
                                    |
                                    | SSH via DRG routing
                                    v
                    APP VCN private subnets (WordPress / DB access)
    
    
    --------------------------- TRAFFIC FLOW ----------------------------
    
    User
      |
      | HTTPS
      v
    Load Balancer
      |
      | HTTP/HTTPS backend traffic
      v
    WordPress VM
      |
      | SQL (private network only)
      v
    Database
    
    
    Admin / Dev
      |
      | SSH (only via Bastion)
      v
    Bastion Host
      |
      | DRG routing
      v
    Private App / DB resources
    
    
    --------------------------- DRG HUB ----------------------------
    
            APP VCN 1 --------\
            APP VCN 2 --------->  DRG (Central Routing Hub)
            APP VCN 3 --------/
            BASTION VCN ------/