Traefik wildcard Lets Encrypt certificate reverse proxy example

The following example builds on our config from Simple Traefik docker-compose setup with Lets Encrypt Cloudflare DNS-01 & TLS-ALPN-01 & HTTP-01 challenges

This config (placed in /etc/traefik/conf/myservice.toml – which is mapped to ./conf/myservice.toml i.e. /opt/traefik/conf/myservice.toml in our docker-compose example) generates a wildcard certificate for *.mydomain.com (also including just mydomain.com) using the cloudflare certificate provider and uses said wildcard certificate for myservice.mydomain.com and any other *.mydomain.com backends you have configured.

This config will reverse proxy all traffic on myservice.mydomain.com to 192.168.178.233:8080

# Host
[http.routers.myservice]
rule = "Host(`myservice.mydomain.com`)"
service = "myservice"

# Backend
[http.services]
[http.services.myservice.loadBalancer]
[[http.services.myservice.loadBalancer.servers]]
url = "http://192.168.178.233:8080/"

# Certificates
[http.routers.myservice.tls]
certresolver = "cloudflare"
[[http.routers.myservice.tls.domains]]
main = "mydomain.com"
sans = ["*.mydomain.com"]

Note that cloudflare in certresolver = "cloudflare" refers to the provider configured using

--certificatesresolvers.cloudflare....

but you can choose any other name with the cloudflare method such as --certificatesresolvers.myprovider.acme.dnschallenge.provider=cloudflare in which case the provider will be referred to as myprovider !