# How to specify server port in dynamic configuration?

**URL:** <https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035>\
**Category:** Traefik v2\
**Tags:** docker-swarm\
**Created:** [September 30, 2019, 8:43am UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035 "2019-09-30T08:43:21Z")\
**Posts on this page:** 10\
**Page:** 1

<div class="post-metadata">

**Author:** ![aleksvujic](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/aleksvujic/32/4885_2.png) [@aleksvujic](https://community.traefik.io/u/aleksvujic)\
**Post date:** [September 30, 2019, 8:43am UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/1 "2019-09-30T08:43:21Z")

</div>

We are able to define the following label for the service:

```auto
traefik.http.services.myservice.loadbalancer.server.port=9000

```

What is the equivalent of the above line in file provider? I suppose it should be something like this, but I didn't find any documentation.

```auto
http:
  services:
    myservice:
      loadbalancer:
        server:
          port: 9000

```

---

<div class="post-metadata">

**Author:** ![ldez](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/ldez/32/5_2.png) [@ldez](https://community.traefik.io/u/ldez)\
**Post date:** [September 30, 2019, 11:09am UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/2 "2019-09-30T11:09:26Z")

</div>

Hello,

In the file provider, a server must be describe by an URL:

```auto
http:
  services:
    my-service:
      loadBalancer:
        servers:
          - url: "http://foobar.com:9080"

```

[https://docs.traefik.io/v2.0/routing/services/#servers](https://docs.traefik.io/v2.0/routing/services/#servers)

The label `traefik.http.services.myservice.loadbalancer.server.port` exists because for a Docker container a user cannot known the IP.

---

<div class="post-metadata">

**Author:** ![aleksvujic](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/aleksvujic/32/4885_2.png) [@aleksvujic](https://community.traefik.io/u/aleksvujic)\
**Post date:** [September 30, 2019, 11:17am UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/3 "2019-09-30T11:17:42Z")

</div>

Let's say I have the following dynamic configuration saved in file in **config** folder:

```auto
http:
  services:
    traefik:
      loadBalancer:
        passHostHeader: true
    whoami:
      loadBalancer:
        passHostHeader: true
        sticky:
          cookie:
            name: StickyCookie
  routers:
    traefik:
      rule: "Host(`example.com`)"
      entryPoints:
        - "traefik"
      service: traefik
    whoami:
      rule: "Host(`example.me`)"
      entryPoints:
        - "web"
      service: whoami

```

And the following **docker-compose** file:

```auto
version: "3.7"

services:
  traefik:
    image: "traefik:v2.0"
    networks:
      - traefik-net
    ports:
      - "9000:9000"
      - "5000:5000"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
      - "./config/:/etc/traefik"
    deploy:
      replicas: 1
      labels:
        - "traefik.http.services.traefik.loadbalancer.server.port=8080"

networks:
  traefik-net:
    external:
      name: traefik-net

```

When I execute `docker stack deploy`, it creates 3 services:

1. traefik (provider file)
2. traefik (provider Docker)
3. whoami (provider file)

This is not what I want. I just want to specify port for traefik service which is defined in file, I don't want to create another service. How can I reference existing traefik service from labels section so that it wouldn't create new one?

---

<div class="post-metadata">

**Author:** ![ldez](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/ldez/32/5_2.png) [@ldez](https://community.traefik.io/u/ldez)\
**Post date:** [September 30, 2019, 11:30am UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/4 "2019-09-30T11:30:11Z")

</div>

Why are you using file you define routers on containers?  
why not just use labels?

* * *

Only labels (I recommend):

```yaml
version: "3.7"

services:
  traefik:
    image: "traefik:v2.0"
    networks:
      - traefik-net
    ports:
      - "9000:9000"
      - "5000:5000"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
      - "./config/:/etc/traefik"
    deploy:
      replicas: 1
      labels:
        - "traefik.http.routers.traefik.rule=Host(`example.com`)"
        - "traefik.http.routers.traefik.entrypoints=traefik"
        - "traefik.http.routers.traefik.service=api@internal"
        - "traefik.http.services.traefik.loadbalancer.server.port=8080" # noop

  whoami:
    image: containous/whoami:v1.3.0
    networks:
      - traefik-net
    deploy:
      labels:
        - "traefik.http.routers.whoami.rule: Host(`example.me`)"
        - "traefik.http.routers.myrouter.entrypoints=web"
        - "traefik.http.services.whoami.loadbalancer.sticky.cookie.name=StickyCookie"

networks:
  traefik-net:
    external:
      name: traefik-net

```

* * *

Mixed labels and file (I don't recommend in your case):

```yaml
version: "3.7"

services:
  traefik:
    image: "traefik:v2.0"
    networks:
      - traefik-net
    ports:
      - "9000:9000"
      - "5000:5000"
    volumes:
      - "/var/run/docker.sock:/var/run/docker.sock:ro"
      - "./config/:/etc/traefik"
    deploy:
      replicas: 1
      labels:
        - "traefik.enable=false"

  whoami:
    image: containous/whoami:v1.3.0
    networks:
      - traefik-net
    deploy:
      labels:
        - "traefik.http.services.whoami.loadbalancer.sticky.cookie.name=StickyCookie"

networks:
  traefik-net:
    external:
      name: traefik-net

```

```yaml
http:
  routers:
    traefik:
      rule: "Host(`example.com`)"
      entryPoints:
        - "traefik"
      service: api@internal
    whoami:
      rule: "Host(`example.me`)"
      entryPoints:
        - "web"
      service: whoami@docker

```

* * *

It cannot be done by using only file.

---

<div class="post-metadata">

**Author:** ![mlanner](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/mlanner/32/8121_2.png) [@mlanner](https://community.traefik.io/u/mlanner)\
**Post date:** [January 19, 2024, 5:11am UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/5 "2024-01-19T05:11:07Z")

</div>

> [@ldez](#):
>
> Why are you using file you define routers on containers?  
> why not just use labels?

I'm trying to do something similar to what is described in this topic and I was curious about the statement quoted above.

I've got an application consisting of multiple containers, all defined as http services. I also have one or a few containers that will need tcp services. My approach has been to use the dynamic config file to define all the services. My reasoning has been that I don't want to have the config done using labels in compose files, as I'd like the compose file(s) to be as clean as possible. Also, we will need to modify the host rules for different installations. Hence, I found it to be cleaner to have all the configuration in the dynamic file, since it seems like that is the purpose of that file.

I would greatly appreciate if you could shed some light on the above statement and maybe also comment on my strategy to provide routing/services for the application behind Traefik.

---

<div class="post-metadata">

**Author:** ![bluepuma77](https://avatars.discourse-cdn.com/v4/letter/b/a9adbd/32.png) [@bluepuma77](https://community.traefik.io/u/bluepuma77)\
**Post date:** [January 19, 2024, 6:41am UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/6 "2024-01-19T06:41:45Z")

</div>

We run a tenant based SaaS. Every new customer gets their own service/instance.

So for every new customer we have a `docker-compose.yml` file which includes the labels for the new sub-domain.

In our case it’s easier to create only one file instead of having to update an additional dynamic config file.

---

<div class="post-metadata">

**Author:** ![mlanner](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/mlanner/32/8121_2.png) [@mlanner](https://community.traefik.io/u/mlanner)\
**Post date:** [January 19, 2024, 9:26pm UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/7 "2024-01-19T21:26:19Z")

</div>

Thanks for the input @bluepuma77. That seems to make sense in your case. Our product is not SaaS, so it's a little harder (read impossible) for us to control each instance. Also, the customer might need/want to be able to modify the installation, both in terms of what services to run and the config of each. So, it seems better and safer to have fewer files to modify, as we need to write configuration tooling to make that possible and safe to do in a running instance.

What stumps me is that when I try to add the tcp router/service in the dynamic config file, it doesn't work. It's not until I add back docker as a provider and use labels that I can get it to work. But, then of course, I also can't find any examples of a config.yml that include both http and tcp sections. The official documentation only shows how to do it with labels. Or I'm somehow not finding the right docs.

---

<div class="post-metadata">

**Author:** ![bluepuma77](https://avatars.discourse-cdn.com/v4/letter/b/a9adbd/32.png) [@bluepuma77](https://community.traefik.io/u/bluepuma77)\
**Post date:** [January 20, 2024, 9:09am UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/8 "2024-01-20T09:09:00Z")

</div>

It should be no problem to use TCP or TCP+http routers in a regular dynamic config file, which you load with `providers.file` in static config.

For use with labels, maybe check [simple Traefik TCP example](https://github.com/bluepuma77/traefik-best-practice/tree/main/docker-traefik-tcp).

The usual challenge is that TCP needs to use TLS/SSL to be routed and Traefik needs the cert to be able to decrypt the request. If Traefik does not have the cert or it’s plain TCP, then you can only use `HostSNI(`*`)` with a single service on that port.

---

<div class="post-metadata">

**Author:** ![mlanner](https://sea2.discourse-cdn.com/flex020/user_avatar/community.traefik.io/mlanner/32/8121_2.png) [@mlanner](https://community.traefik.io/u/mlanner)\
**Post date:** [January 24, 2024, 8:01pm UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/9 "2024-01-24T20:01:31Z")

</div>

Hi @bluepuma77, thanks for the input. I've been using `HostSNI(`\*`)` in my testing and I finally got this to work (for the most part), using a dynamic config file, like `config.yml`. As noted in my original question/comment, for my use-case, I don't particularly care for or like to use labels, as that will "muddle" the structure of the application and mix in configs into my compose files. I need to keep those as clean as possible, reducing the need to modify anything in those and instead drive all settings into config files based on runtime configs. Hence, in my case it seems like a bad idea to use labels and carry those around and subsequently having to modify them for each installation. I see how that definitely could work in some situations, but not so much for what I'm working on.

Thanks again for your suggestions, as it helped me get on the right path.

---

<div class="post-metadata">

**Author:** ![bluepuma77](https://avatars.discourse-cdn.com/v4/letter/b/a9adbd/32.png) [@bluepuma77](https://community.traefik.io/u/bluepuma77)\
**Post date:** [January 24, 2024, 8:16pm UTC](https://community.traefik.io/t/how-to-specify-server-port-in-dynamic-configuration/2035/10 "2024-01-24T20:16:27Z")

</div>

It doesn’t really matter, dynamic config can be read from `providers.file` or `providers.docker`.

The latter will just auto-provide the target IP, which you have to set yourself in file.