Deployment Overview of MicroK8s on Server¶

Prerequisites and Basic Requirements¶

To ensure a successful deployment, the following requirements must be met:

Operating System: Ubuntu
Privileges: Root or sudo access is required for all installation steps.
Package Manager: apt and snapd must be available.
Network Access: The server requires outbound internet access to download packages via apt and snap.

Application Installation Process¶

The application is installed using a combination of system package management and the Snap package manager. The installation process follows these steps:

Docker Engine Installation: Docker is installed on the host system to support containerized workloads.
Package Index Update: The apt package index is updated to ensure all dependencies are current.
Snapd Installation: The snapd service is installed via apt.
MicroK8s Installation: MicroK8s (version 1.31/stable) is installed using the Snap package manager with the --classic confinement flag.
User Configuration: The root user is added to the microk8s group to allow necessary permissions for cluster management.
Addon Activation: The following MicroK8s addons are enabled:
dns: Provides internal DNS services within the cluster.
hostpath-storage: Provides local storage capabilities using host paths.
dashboard: Deploys the Kubernetes web-based user interface.
CLI Configuration: A command alias is created so that kubectl can be used directly via microk8s kubectl.

Docker Containers and Their Deployment¶

The deployment includes a specialized Nginx container managed via Docker Compose to handle SSL certificate management.

Service	Image	Ports	Volumes	Environment Variables	Restart Policy
`nginx`	`jonasal/nginx-certbot:latest`	Host Network Mode	`- nginx_secrets:/etc/letsencrypt` `- /data/nginx/user_conf.d:/etc/nginx/user_conf.d`	`[email protected]`	`unless-stopped`

Custom Scripts and Additional Setup¶

The following actions are performed during the initial setup to ensure service availability:

Dashboard Access Token Generation: An access token is generated for the Kubernetes Dashboard using the command microk8s kubectl create token default.
Port Forwarding: A background process is initiated to forward the Kubernetes Dashboard port from the cluster to the host at 10443:443 to allow external management access.

Location of Configuration Files and Data¶

The following paths are used for configuration and persistent data:

Nginx/Certbot Secrets: Managed via an external Docker volume named nginx_secrets.
Nginx User Configurations: /data/nginx/user_conf.d
Nginx Environment Variables: /data/nginx/nginx-certbot.env

Available Ports for Connection¶

The following ports are utilized by the application:

10443: Kubernetes Dashboard (via port forwarding).
80/443: Managed via Nginx in host network mode for SSL termination.

Starting and Stopping the Application¶

Management of the MicroK8s service is performed using the following commands:

Check Status: microk8s status
Enable Addons: microk8s enable <addon_name>
Kubectl Command Usage: Use kubectl (via the created alias) for all cluster management tasks.