computer-playbook/roles/nginx-docker-cert-deploy

Nginx Docker Cert Deploy Role

🎉 Author: Kevin Veen-Birkenbach

This Ansible role simplifies the deployment of Let's Encrypt certificates into Docker Compose setups with Nginx. It supports both individual certificates per subdomain and a single wildcard certificate for all subdomains.

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🚀 Features

• Automatically deploys Let's Encrypt certificates to Docker Compose setups.
• Supports both single-domain certificates and one wildcard certificate for all subdomains.
• Copies certificates to the target directory inside the container.
• Automatically reloads or restarts Nginx services when certificates are updated.
• Configures and manages a systemd service for automated certificate deployment.
• Includes a systemd timer for scheduled renewals.
• Handles dependent services like systemd-notifier.

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📋 Configuration Options

🔹 One Wildcard Certificate for All Subdomains

By default, each subdomain gets its own certificate. You can enable a wildcard certificate by setting:

enable_one_letsencrypt_cert_for_all: true

📌 Pros & Cons of a Wildcard Certificate: ✅ Improves performance by reducing TLS handshakes.
✅ Simplifies certificate management (one cert for all subdomains).
⚠ Requires manual DNS challenge setup for Let's Encrypt.
⚠ Needs additional configuration for automation (see below).

If enabled, update your inventory file and follow the manual wildcard certificate setup below.

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🔧 Tasks Overview

1️⃣ Main Tasks

1. Add Deployment Script

   • Copies nginx-docker-cert-deploy.sh to the administrator scripts directory.

2. Create Certificate Directory

   • Ensures cert_mount_directory exists with proper permissions.

3. Configure systemd Service

   • Deploys a systemd service file for the deployment process.

4. Include systemd-timer Role

   • Schedules automatic certificate deployment using a systemd timer.

2️⃣ Handlers

• Restart Nginx Service
  • Restarts nginx-docker-cert-deploy whenever a certificate update occurs.

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🔐 Wildcard Certificate Setup with Let's Encrypt

If you enabled enable_one_letsencrypt_cert_for_all, follow these steps to manually request a wildcard certificate.

1️⃣ Run the Certbot Command 🖥️

certbot certonly --manual --preferred-challenges=dns --agree-tos \
--email administrator@primary_domain -d primary_domain -d "*.primary_domain"

2️⃣ Add DNS TXT Record for Validation 📜

Certbot will prompt you to add a DNS TXT record:

Please create a TXT record under the name:
_acme-challenge.primary_domain.

with the following value:
9oVizYIYVGlZ3VtWQIKRS5UghyXiqGoUNlCtIE7LiA

➡ Go to your DNS provider and create a new TXT record:

• Host: _acme-challenge.primary_domain
• Value: "9oVizYIYVGlZ3VtWQIKRS5UghyXiqGoUNlCtIE7LiA"
• TTL: Set to 300 seconds (or lowest possible)

✅ Verify the DNS record before continuing:

dig TXT _acme-challenge.primary_domain @8.8.8.8

3️⃣ Complete the Certificate Request ✅

Once the DNS changes have propagated, press Enter in the Certbot terminal.
If successful, Certbot will save the certificates under:

/etc/letsencrypt/live/primary_domain/

• fullchain.pem → The certificate
• privkey.pem → The private key

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📂 File & Directory Structure

roles/nginx-docker-cert-deploy/
├── files/
│   ├── nginx-docker-cert-deploy.sh  # Deployment script
├── handlers/
│   ├── main.yml  # Restart Nginx handler
├── meta/
│   ├── main.yml  # Dependencies
├── tasks/
│   ├── main.yml  # Main Ansible tasks
├── templates/
│   ├── nginx-docker-cert-deploy.service.j2  # Systemd service template
├── vars/
│   ├── main.yml  # Variable definitions

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🔧 Deploying Certificates into Docker Containers

The role automates copying certificates into Docker Compose setups.

1️⃣ Deployment Script (nginx-docker-cert-deploy.sh)

This script:

• Copies certificates to the correct container directory.
• Reloads Nginx inside all running containers.
• Restarts containers if needed.

Usage:

sh nginx-docker-cert-deploy.sh primary_domain /path/to/docker/compose

2️⃣ Systemd Service & Timer

The role includes a systemd service that runs the deployment script whenever certificates are updated.

Example nginx-docker-cert-deploy.service.j2:

[Unit]
Description=Let's Encrypt deploy to {{docker_compose_instance_directory}}
OnFailure=systemd-notifier.cymais@%n.service

[Service]
Type=oneshot
ExecStart=/usr/bin/bash {{path_administrator_scripts}}/nginx-docker-cert-deploy.sh {{primary_domain}} {{docker_compose_instance_directory}}

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🎯 Summary

Feature	Description
Single-domain & wildcard support	Use individual certs or a wildcard certificate
Automated renewal	Cronjob or systemd timer ensures auto-renewals
Docker-ready	Deploys certificates directly into Docker containers
Supports Nginx & Mailu	Compatible with multiple services
Systemd integration	Automates deployment via systemd

🚀 Now your Nginx setup is fully automated and secured with Let's Encrypt! 🎉