Certbot_Only

Certbot_Only is a docker image based off of linuxserver's SWAG with the goal to simplify the image to only generate DNS certificates and maintain them while leaving them accessible for other resources to utilize. Because Certbot_Only only runs certbot and a monitoring cron task, DNS validation is required. Further, in order to simplify the image, only Cloudflare DNS is currently implemented.

Supported Architectures

The project is built with Docker Buildx to support multiple architectures such as amd64 and arm64.

Simply pulling ahgraber/certbot_only should retrieve the correct image for your arch, but you can also pull specific arch images via tags.

The architectures supported by this image are:

Architecture	Tag
x86-64	amd64-latest
arm64	arm64v8-latest

Usage

Here are some example snippets to help you get started creating a container.

docker-compose (recommended)

Compatible with docker-compose v3 schemas.

---
version: "3.7"
services:
  swag:
    image: ahgraber/certbot_only:latest
    container_name: certbot
    environment:
      - TZ=Europe/London
      - URL=yourdomain.url
      - SUBDOMAINS=www,
      - ONLY_SUBDOMAINS=false #optional
      - PROPAGATION= #optional
      - EMAIL= #optional
      - STAGING=false #optional
    volumes:
      - /path/to/appdata/config:/config
      - /path/to/appdata/letsencrypt:/letsencrypt
    ports:
      - 443:443
      - 80:80 #optional
    restart: unless-stopped

Parameters

Container images are configured using parameters passed at runtime (such as those above).

Parameter	Function
TZ=Europe/London	Specify a timezone to use - e.g., Europe/London.
TLD: yourdomain.url	Top url you have control over (customdomain.com if you own it, or customsubdomain.ddnsprovider.com if dynamic dns).
SUBDOMAINS: 'www'	Subdomains you'd like the cert to cover (comma separated, no spaces) ie. www,ftp,cloud. For a wildcard cert, set this exactly to wildcard (wildcard cert is available via dns and duckdns validation only)
ONLY_SUBDOMAINS: 'false'	If you wish to get certs only for certain subdomains, but not the main domain (main domain may be hosted on another machine and cannot be validated), set this to true
PROPAGATION: 60	Optionally override (in seconds) the default propagation time for the dns plugins.
EMAIL: you@email.com	Optional e-mail address used for cert expiration notifications.
STAGING: 'false'	Set to true to retrieve certs in staging mode. Rate limits will be much higher, but the resulting cert will not pass the browser's security test. Only to be used for testing purposes.

Environment variables from files (Docker secrets)

You can set any environment variable from a file by using a special ending __FILE (double-underscore FILE).

As an example:

-e PASSWORD__FILE=/run/secrets/mysecretpassword

Will set the environment variable PASSWORD based on the contents of the /run/secrets/mysecretpassword file.

Volumes

The recommended configurations create local folders /config and /letsencrypt.
config/
├ credentials/ - contains cloudflare.ini. Edit with your own credentials. ├ crontabs - contains root crontab
└ deploy/ - contains deploy scripts for actions following successful Let's Encrypt renewal. If you add scripts, they will be run automatically following successful renewal.

letsencrypt/ is populated with Let's Encrypt certificates if the generation/renewal is successful.

 

Application Setup

Validation and initial setup

• For dns validation, make sure to enter your credentials into the corresponding .ini file under /config/credentials/cloudflare.ini. You may have to start the container once to locate the file in the local volume mount.
  • Cloudflare provides free accounts for managing dns and is very easy to use with this image. Make sure that it is set up for "dns only" instead of "dns + proxy"
• Certs are checked nightly and if expiration is within 30 days, renewal is attempted. If your cert is about to expire in less than 30 days, check the logs under /config/log/letsencrypt to see why the renewals have been failing. It is recommended to input your e-mail in docker parameters so you receive expiration notices from Let's Encrypt in those circumstances.

Using certs in other containers

• This container includes auto-generated pfx and private-fullchain-bundle pem certs that are needed by other apps like Emby and Znc, and tls.crt and tls.key certs that are needed by apps like Keycloak.
  • To use these certs in other containers, do either of the following:
  1. (Easier) Mount the container's config folder in other containers (ie. -v /path-to-le-config:/le-ssl) and in the other containers, use the cert location /le-ssl/keys/letsencrypt/
  2. (More secure) Mount the cert folder /letsencrypt (ie. -v /path/to/letsencrypt:/le-ssl) and in the other containers, use the cert location /le-ssl/letsencrypt/live/<your.domain.url>/ (This is more secure because the first method shares the entire SWAG config folder with other containers, including the www files, whereas the second method only shares the ssl certs)
  • These certs include:
  1. cert.pem, chain.pem, fullchain.pem and privkey.pem, which are generated by Certbot and used by nginx and various other apps
  2. privkey.pfx, a format supported by Microsoft and commonly used by dotnet apps such as Emby Server (no password)
  3. priv-fullchain-bundle.pem, a pem cert that bundles the private key and the fullchain, used by apps like ZNC
  4. tls.crt and tls.key, formats which are used by x509 apps like Keycloak

Support Info

• Shell access whilst the container is running: docker exec -it certbot_only /bin/with-contenv bash
• To monitor the logs of the container in realtime: docker logs -f certbot_only
• container version number
  • docker inspect -f '{{ index .Config.Labels "build_version" }}' certbot_only
• image version number
  • docker inspect -f '{{ index .Config.Labels "build_version" }}' ahgraber/certbot_only

Updating Info

Below are the instructions for updating containers:

Via Docker Compose

• Update all images: docker-compose pull
  • or update a single image: docker-compose pull certbot_only
• Let compose update all containers as necessary: docker-compose up -d
  • or update a single container: docker-compose up -d swag
• You can also remove the old dangling images: docker image prune

Via Docker Run

• Update the image: docker pull ahgraber/certbot_only
• Stop the running container: docker stop certbot_only
• Delete the container: docker rm certbot_only
• Recreate a new container with the same docker run parameters as instructed above (if mapped correctly to a host folder, your /config folder and settings will be preserved)
• You can also remove the old dangling images: docker image prune

Building locally

If you want to make local modifications to these images for development purposes or just to customize the logic:

With Docker Compose for single testing:

git clone https://github.com/ahgraber/docker-certbot-only.git
cd docker-certbot_only
docker-compose build

With Docker buildx for multiarch support:

git clone https://github.com/ahgraber/docker-certbot-only.git
cd docker-certbot_only
bash ./scripts/buildx.sh --tag {REPOSITORY}/certbot_only:{TAG}

Versions

11 Feb 2021: Cloned from linuxserver/docker-swag adfe04cedb