Traefik redirect from one host to another - redirect

Question

We decided to move from the subdomain structure to one root domain with path prefixes, but we got many old URLs on the internet. So is there any way to add a redirect from the old URL to the new one?
For example,
We got subdomain test.example.com switched to example.com/test, I can access correctly site with the string in docker-swarm YAML file
traefik.frontend.rule: Host:example.com;PathPrefixStrip:/test
but when I'm trying to add to Traefik config redirects like:
[http.middlewares]
[http.middlewares.test-redirectregex.redirectRegex]
regex = "^https://(*).example.com/)"
replacement = "^https://example.com/${1}"
Traefik says that it doesn't know where to forward this request
If I'm trying to add:
traefik.frontend.rule: Host:test.example.com,example.com;PathPrefixStrip:/test
Traefik adds a prefix to both hosts. Is there any way to resolve this without adding a second reverse proxy?

Answer 1

Assuming that you are using Traefik 2.1, you can use the below middleware for Traefik
[http.middlewares]
[http.middlewares.blog-redirect.redirectRegex]
regex = "^(https?://)(.*).example.com/(.*)$"
replacement = "${1}example.com/${2}/${3}"
permanent = true
The important step to activate the above middleware is to add the below label on the corresponding router and service. For instance, if you a a blog service and you defined a blog router for it, then you need to add the below table to the services
traefik.http.routers.blog.middlewares=blog-redirect
In addition, your route rule should look like the below rule to be able to handle both domains (or you define multiple routes per service)
- traefik.http.routers.blog.rule=Host(`example.com`) && Path(`/test`) || Host(`api.example.com``)
in this post, you can find more info about traffic and redirection