Lazy Librarian Deployment - Role Overview

This page documents the Lazy Librarian Docker deployment using Ansible, illustrating the workflow, architecture, and best practices for deploying this containerized application with version control, persistent storage, and templated configuration.

1. Overview

Lazy Librarian is deployed in a Docker container using Ansible. Key steps include:

Stop existing container safely
Prepare persistent configuration and backup directories
Deploy templated Docker Compose file
Version control the Docker image to prevent accidental upgrades
Start the container

Lazy Librarian manages its own internal configuration and does not require an external database, simplifying deployment while maintaining persistent storage for e-books, download history, and settings.

2. Persistent Configuration and Backups

Persistent storage ensures application data is preserved across container restarts:

Configuration directory: /config/lazylibrarian
Backup directory: /nfs/backups/lazy

Example variables from the role:

lazylibrarian_setup_config_dir: "/config/lazylibrarian"
lazylibrarian_setup_backups_dir: "{{ lazylibrarian_setup_mount_point }}/lazy"
lazylibrarian_setup_backup_filename: "{{ lazylibrarian_setup_backup_prefix }}{{ ansible_date_time.date }}.sqlc"

Directories are created and owned by a dedicated system user
Supports NFS-mounted storage for centralized backups
Ensures container can read/write configuration, ebook libraries, and backup files

3. Docker Image Version Control

The role pins a specific Docker image version:

lazylibrarian_setup_version: 0c862d0f
lazylibrarian_setup_docker_image_name: "lazylibrarian:version-{{ lazylibrarian_setup_version }}"

Avoids pulling latest automatically
Guarantees reproducible deployments
Allows testing and validation of known working versions

4. Deployment Workflow

The sequence for deploying Lazy Librarian is:

Stop and remove existing container

docker stop lazylibrarian
docker rm lazylibrarian
docker network prune -f

Ensure persistent directories exist

mkdir -p {{ lazylibrarian_setup_config_dir }}
mkdir -p {{ lazylibrarian_setup_backups_dir }}
chown <user>:<group> {{ lazylibrarian_setup_config_dir }}

Deploy Docker Compose file

docker-compose.yml (templated in the role)

Prune unused Docker images (optional)

docker image prune -f

Pull the pinned Docker image

docker-compose -f {{ lazylibrarian_setup_config_dir }}/docker-compose.yml pull

Start the container

docker-compose -f {{ lazylibrarian_setup_config_dir }}/docker-compose.yml up -d

5. Architecture Diagram

                 ┌──────────────────────────────┐
                 │  Host / Docker Environment   │
                 │                              │
                 │ ┌──────────────────────────┐ │
                 │ │ Lazy Librarian Container │ │
                 │ │ - Pinned Image           │ │
                 │ │ - Config & Backup Volumes│ │
                 │ │ - Exposed Port 5299      │ │
                 │ └──────────────────────────┘ │
                 │                              │
                 └────────────────▲─────────────┘
                                 │ Access
                 ┌───────────────┴─────────────┐
                 │ Users / Clients             │
                 │ Web Browser / API           │
                 └─────────────────────────────┘

Config directory is mounted inside the container
Backups can reside on NFS for centralized storage
Container manages its own internal data for ebooks and download management

6. Key Features

Automated deployment via Ansible
Persistent configuration and backup support
Pinned Docker image version for reproducibility
Optional NFS storage for backups
Template-driven Docker Compose for flexible setup
No external database dependencies, self-contained configuration

7. Summary

The Lazy Librarian deployment role demonstrates a simple, containerized workflow:

Safe, repeatable container start/stop sequences
Version-controlled Docker images to prevent accidental updates
Persistent storage and automated backups for configuration and ebook libraries
Template-driven Docker Compose to allow scalable and consistent deployments

This workflow can be adapted for other containerized applications in the home lab, ensuring maintainability, reliability, and consistent infrastructure-as-code practices.