Traefik ConsulCatalog defaultRule with Labels

Traefik Traefik v2
,
#1

Hey guys,

I'm trying to use a specific Label at my service definition as part of the URL.

---
apiVersion: v1
kind: Service
metadata:
  name: example0
  labels: 
    test: myapp0
spec:
  selector:
    app: example
  ports:
    - port: 80

With the defaultRule at the traefik command-CLI

...
- --providers.consulcatalog.defaultRule=Host("{{ regexReplaceAll `([^-].*)\-.*` .Name `$1` }}.{{ index .Labels `test`}}.k8s")
...

I only get example0..k8s.example.com; the value of my customLabel 'test' is missing.
I assume the label is missing in ConsulCatalog too.
How to check this? How to bring the Label from K8s to Consul Catalog?

#2

Hello @Raskosk.

You mention that you are using the Traefik CLI, but how are you using it? Is it in a kubernetes manifest? is it in a helm template?

If you are wanting to use label values on a container, you may want to use the downward API (Expose Pod Information to Containers Through Files | Kubernetes)

#4

As you can see above, I'm using a DaemonSet to deploy traefik.

I'm now trying to implement the default example of Traefik-Documentation according to ConsulCatalog Default Rule. - --providers.consulcatalog.defaultRule=Host("{{ .Name }}.{{ index .Labels test}}.k8s.example.com") to get sth like example0.myapp0.k8s.example.com.

But actually, I'm ending up with a result like example0..k8s.example.com.

Can you help?

#5

@daniel.tomcej
Any idea's about how to retrieve labels or annotations within the default rule?

#6

Hello @Raskosk

Can you please try the following example as the reference:

providers:
  docker:
     exposedByDefault: false
  consulCatalog:
    refreshInterval:  "10s"
    endpoint:
      address: "consul:8500"
      scheme: "http"
    defaultRule: "Host(`{{ index .Labels \"application_name\" }}.{{ index .Labels \"env\" }}.{{.Name}}`)"
#7

Hey @jakubhajek,
I've just tried this, without any success.
The test-service is:

apiVersion: v1
kind: Service
metadata:
  name: example
  labels: 
    test: 'banana'
    env: 'dev'
  annotations:
    'consul.hashicorp.com/service-sync': 'true'
    'consul.hashicorp.com/service-meta-test': 'banana'
spec:
  selector:
    app: example
  ports:
    - port: 80

The applied defaultRule is

- --defaultRule="Host(`{{ index .Labels \"test\" }}.{{ index .Labels \"env\" }}.{{.Name}}`)"

Ending up with this:

image
image1484×147 19.2 KB

It seems consulCatalog doesn't provide labels to use them in defaultRule...

Do you got any working examples by using labels or annotations?