Contacts/Calendar server with Radicale

Radicale is a CalDAV and CardDAV server.

The radicale service will be run in a docker container using our reverse proxy.

Radicale doesn’t provide an image on dockerhub, but has a dockerfile on github, which we slightly adjust:

FROM python:3-alpine

ARG VERSION=master
VOLUME /var/lib/radicale
VOLUME /etc/radicale
EXPOSE 80
CMD ["radicale", "--config", "/etc/radicale/radicale.ini"]

RUN apk add --no-cache build-base ca-certificates openssl
RUN pip install --no-cache-dir "Radicale[bcrypt] @ https://github.com/Kozea/Radicale/archive/${VERSION}.tar.gz"
RUN apk del build-base

Next we’ll create a docker-compose.yml in the same folder as our dockerfile:

version: "3.9"

services:
    radicale:
        build: .
        networks: ["server"]
        restart: "always"
        labels:
            - "traefik.enable=true"
            - "traefik.http.routers.radicale.rule=Host(`radicale.<YOUR_DOMAIN>`)"
        volumes:
            - "./data/persistence:/var/lib/radicale"
            - "./data/config:/etc/radicale"

networks:
    server:
        external: true

In the docker-compose file we mounted two volumes data/persistence and data/config. Persistence is used to store calendar/contacts data for each user. We’ll use the config folder to configure radicale:

1. Create a new file data/config/radicale.ini

   [server]
   # Bind all addresses
   hosts = 0.0.0.0:80
   
   [auth]
   type = htpasswd
   htpasswd_filename = /etc/radicale/users
   htpasswd_encryption = bcrypt
   [storage]
   filesystem_folder = /var/lib/radicale/collections
   [web]
   type = internal
   [rights]
   type = owner_only
   [logging]
   level = warning
   

2. Setup users
   • Create a new file data/config/users and add each user like this, separated by linebreak:

     <USERNAME>:<BCRYPT_PASSOWRD_HASH>

   • To create a password hash with bcrypt use the following python script

     python3 -c 'import bcrypt; print(bcrypt.hashpw(b"<PLAIN_PASSWORD>", bcrypt.gensalt(rounds=15)).decode("ascii"))'
     

Now you should be able to access the webservice of radicale via browser (radicale.<YOUR_DOMAIN>) and login with the credentials from the users file. After creating a calendar and an address book you should see them listed with their urls, which are needed for client setup.

• radicale