Docker-compose with Let's Encrypt: TLS Challenge¶
This guide aims to demonstrate how to create a certificate with the Let's Encrypt TLS challenge to use https on a simple service exposed with Traefik.
Please also read the basic example for details on how to expose such a service.
Prerequisite¶
For the TLS challenge you will need:
- A publicly accessible host allowing connections on port
443
with docker & docker-compose installed. - A DNS record with the domain you want to expose pointing to this host.
Setup¶
- Create a
docker-compose.yml
on your remote server with the following content:
version: "3.3"
services:
traefik:
image: "traefik:v3.1"
container_name: "traefik"
command:
#- "--log.level=DEBUG"
- "--api.insecure=true"
- "--providers.docker=true"
- "--providers.docker.exposedbydefault=false"
- "--entryPoints.websecure.address=:443"
- "--certificatesresolvers.myresolver.acme.tlschallenge=true"
#- "--certificatesresolvers.myresolver.acme.caserver=https://acme-staging-v02.api.letsencrypt.org/directory"
- "--certificatesresolvers.myresolver.acme.email=postmaster@example.com"
- "--certificatesresolvers.myresolver.acme.storage=/letsencrypt/acme.json"
ports:
- "443:443"
- "8080:8080"
volumes:
- "./letsencrypt:/letsencrypt"
- "/var/run/docker.sock:/var/run/docker.sock:ro"
whoami:
image: "traefik/whoami"
container_name: "simple-service"
labels:
- "traefik.enable=true"
- "traefik.http.routers.whoami.rule=Host(`whoami.example.com`)"
- "traefik.http.routers.whoami.entrypoints=websecure"
- "traefik.http.routers.whoami.tls.certresolver=myresolver"
- Replace
[email protected]
by your own email within thecertificatesresolvers.myresolver.acme.email
command line argument of thetraefik
service. - Replace
whoami.example.com
by your own domain within thetraefik.http.routers.whoami.rule
label of thewhoami
service. -
Optionally uncomment the following lines if you want to test/debug:
#- "--log.level=DEBUG" #- "--certificatesresolvers.myresolver.acme.caserver=https://acme-staging-v02.api.letsencrypt.org/directory"
-
Run
docker-compose up -d
within the folder where you created the previous file. - Wait a bit and visit
https://your_own_domain
to confirm everything went fine.
Note
If you uncommented the acme.caserver
line, you will get an SSL error, but if you display the certificate and see it was emitted by Fake LE Intermediate X1
then it means all is good.
(It is the staging environment intermediate certificate used by Let's Encrypt).
You can now safely comment the acme.caserver
line, remove the letsencrypt/acme.json
file and restart Traefik to issue a valid certificate.
Explanation¶
What changed between the basic example:
- We replace the
web
entry point by one for the https traffic:
command:
# Traefik will listen to incoming request on the port 443 (https)
- "--entryPoints.websecure.address=:443"
ports:
- "443:443"
- We configure the TLS Let's Encrypt challenge:
command:
# Enable a tls challenge named "myresolver"
- "--certificatesresolvers.myresolver.acme.tlschallenge=true"
- We add a volume to store our certificates:
volumes:
# Create a letsencrypt dir within the folder where the docker-compose file is
- "./letsencrypt:/letsencrypt"
command:
# Tell to store the certificate on a path under our volume
- "--certificatesresolvers.myresolver.acme.storage=/letsencrypt/acme.json"
- We configure the
whoami
service to tell Traefik to use the certificate resolver namedmyresolver
we just configured:
labels:
# Uses the Host rule to define which certificate to issue
- "traefik.http.routers.whoami.tls.certresolver=myresolver"