Normalize auto generated frontend-rule (docker)

[WTFKr0]

What version of Traefik are you using (traefik version)?

Version: v1.1.2
Codename: camembert
Go version: go1.7.4
Built: 2016-12-15_10:21:15AM
OS/Arch: linux/amd64

What is your environment & configuration (arguments, toml...)?

/traefik --web --retry --retry.attempts=10 --docker --docker.watch --docker.swarmmode --docker.domain=my.domain.org --logLevel=DEBUG --entryPoints=Name:http Address::80 Redirect.EntryPoint:https --defaultEntryPoints=http,https --web.address=:8081 --entryPoints=Name:http2 Address::8080 --entryPoints=Name:https Address::443 TLS:traefik.crt,traefik.key

What did you do?

I use docker 1.13 rc7, with a docker-compose file and the docker stack deploy command
This create a service (swarm mode) named

<stack>_<service>

What did you expect to see?

I want traefik create a frontend rule like

<stack>-<service>.<default_domain>

What did you see instead?

Traefik take the service name, so

<stack>_<service>.<default_domain>

So what can we do?

Can traefik change the underscore to hyphen in the normalize process ?
Cause underscores are not valid URI character
See https://tools.ietf.org/html/rfc1035

<domain> ::= <subdomain> | " "

<subdomain> ::= <label> | <subdomain> "." <label>

<label> ::= <letter> [ [ <ldh-str> ] <let-dig> ]

<ldh-str> ::= <let-dig-hyp> | <let-dig-hyp> <ldh-str>

<let-dig-hyp> ::= <let-dig> | "-"

<let-dig> ::= <letter> | <digit>

<letter> ::= any one of the 52 alphabetic characters A through Z in
upper case and a through z in lower case

<digit> ::= any one of the ten digits 0 through 9

Thanx for reading

[WTFKr0]

I think we have to do that in that line :
https://github.com/containous/traefik/blob/913a297e8d2f5279bef79b29cb803f30e5aa5ef1/provider/docker.go#L398
We can't use normalize function as we need to keep dot in url :)

[WTFKr0]

I made a PR for that : #1061
WDYT @emilevauge