This is tested with Traefik 1.7
This is how to redirect the root or base path to a sub path in Traefik using Docker labels:
Goals
https://example.com->https://example.com/abc/xyz/https://example.com/->https://example.com/abc/xyz/https://example.com/something-> no redirect
We will match <begin of line>https://<any chars but not slash AS group1><slash or nothing><end of line>
and replace it with https://<group1>/abc/xyz/.
In regex we have to escape a / character by \/. In docker-compose labels we need to escape again, so that it becomes \\\\/.
We also need to escape $ to $$ because of docker-compose.
labels:
- "traefik.frontend.rule=Host:example.com"
- "traefik.frontend.redirect.regex=^https:\\\\/\\\\/([^\\\\/]+)\\\\/?$$"
- "traefik.frontend.redirect.replacement=https://$$1/abc/xyz/"
- "traefik.port=80"
- "traefik.enable=true"
Thank you, thank you, thank you!!