Use labels to set custom HTTP headers in Docker backend

[DamiaPoquet]

Do you want to request a feature or report a bug?

Request a feature

What did you do?

Add a label to the Docker container like this:

traefik.frontend.customResponseHeaders=X-Custom-Header: foo; bar

What did you expect to see?

Traefik should use the Header Middleware described in #1236 to serve the application with the desired header.

What did you see instead?

Nothing happens.

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

Version:      v1.4.0-rc1
Codename:     roquefort
Go version:   go1.9
Built:        2017-08-29_08:35:24AM
OS/Arch:      linux/amd64

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

graceTimeOut = "10s"
traefikLogsFile = "/var/log/traefik/traefik.log"
accessLogsFile = "/var/log/traefik/access.log"
logLevel = "WARN"

[acme]
email = "[email protected]"
storage = "acme.json"
entryPoint = "https"
acmeLogging = true
OnHostRule = true

[entryPoints]
  [entryPoints.http]
  address = ":80"
    [entryPoints.http.redirect]
      entryPoint = "https"
  [entryPoints.https]
  address = ":443"
    [entryPoints.https.tls]

[web]
address = ":8080"

[docker]
endpoint = "unix:///var/run/docker.sock"
domain = "docker.domain"
watch = true
exposedbydefault = false

[dtomcej]

I would like to take a crack at this first.

Have cycles this week. Should have a PR started today.

[srwhite]

This looks like a great step forward. However, and I'm not an expect in this code, but from a quick look:

• I don't believe it addresses the security options that were added in Create Header Middleware #1236 ( https://github.com/unrolled/secure#available-options ) , though in most or all cases I think a custom header could be used to achieve the same affect anyway.
• I don't believe it addresses the same issue for annotations on Kubernetes Ingress resources.

It would be nice if we could make all of these methods of configuration equivalent without having to duplicate the list of options in each provider.

[faburem]

+1 I think this would be a great improvement to set custom headers on a container level

[danielbehrendt]

+1

[ldez]

Remember the gentle way to participate:

• add a "reaction" on the first message of the issue.
• add more useful and detailed information on the subject.
• resolve the issue by making a PR.