Traefik Redirect Domain to Subdomain - lets-encrypt

Question

I want to permanently redirect all requests to example.com and www.example.com to blog.example.com in a TLS environment.
My current config:
traefik.toml:
[entryPoints]
[entryPoints.web]
address = ":80"
[entryPoints.web.http.redirections.entryPoint]
to = "websecure"
scheme = "https"
[entryPoints.websecure]
address = ":443"
[providers.docker]
exposedbydefault = false
watch = true
network = "web"
[providers.file]
filename = "traefik_dynamic.toml"
[certificatesResolvers.lets-encrypt.acme]
email = "mymail#example.com"
storage = "/letsencrypt/acme.json"
[certificatesResolvers.lets-encrypt.acme.dnsChallenge]
provider = "myprovider"
traefik_dynamic.toml:
[http.middlewares]
[http.middlewares.goToBlog.redirectregex]
regex = "^https://(.*)example.com/(.*)"
replacement = "https://blog.example.com/$${2}"
permanent = true
[http.routers]
[http.routers.gotoblog]
rule = "Host(`example.com`) || Host(`www.example.com`)"
entrypoints = ["websecure"]
middlewares = ["goToBlog"]
service = "noop#internal"
[http.routers.gotoblog.tls]
certResolver = "lets-encrypt"
When I try to access example.com it gives my an SSL Protocol Error. All my other endpoints including blog.example.com are working. What am I doing wrong?

Answer 1

Okey, obviously it had nothing to do with my redirect configuration. Seemed like a hickup in traefik / docker, similar to ACME certificates timeout with traefik. Just waited one day and everything worked as expected. Just two minor updates to correct the redirect configuration. Maybe there's a more elegant solution.
traefik_dynamic.toml:
[http.middlewares]
[http.middlewares.goToBlog.redirectregex]
regex = "^https://(.*)example.com/(.*)"
replacement = "https://blog.example.com/${2}" # no double $$
permanent = true
[http.routers]
[http.routers.gotoblog]
rule = "Host(`example.com`, `www.example.com`)" # just an array of domains is fine, too
entrypoints = ["websecure"]
middlewares = ["goToBlog"]
service = "noop#internal"
[http.routers.gotoblog.tls]
certResolver = "lets-encrypt"