documentation miss: Docker label PROMETHEUS_EXPORTER_PORT should be defined in ECS Task definition

[muravjov]

First of all: thanks, it works.

But the documentation lacks information how to set docker label(s). I tried to to set up PROMETHEUS_EXPORTER_PORT in Dockerfile like

LABEL "PROMETHEUS_EXPORTER_PORT"="5000"

but still failed to write non-empty ecs_file_sd.yml . The log still featured

2021/06/12 04:00:51 Writing 0 discovered exporters to ecs_file_sd.yml

After poking with ECS services I managed to add

"dockerLabels": {
        "PROMETHEUS_EXPORTER_PORT": "5000"
      }

to the ECS task definition JSONs and it is what really fixed the issue.

I'm somewhat new to AWS ECS service stuff and maybe propagating real docker labels can be made, but current documentation is misleading, e.g. the words

To scrape the containers add following docker labels to them:
    PROMETHEUS_EXPORTER_PORT specify the container port where prometheus scrapes (mandatory)

[chicofranchico]

Hi, I don't see where this information is missing. If you think the documentation is lacking, just make a pull request and we can review it. Thanks!

[muravjov]

@chicofranchico done in PR #69 pls review

[chicofranchico]

That's much clearer indeed. Thanks for that.

[gopkris2000]

@chicofranchico @muravjov I deployed the prometheus-ecs-discovery container in one of my AWS EC2 instance. It is running fine but getting the same "Writing 0 discovered exporters to /tmp/ecs_file_sd.yml" errors.

The confusion part is here, I tried to setup dockerLabels in my ECS task definition but showing a huge number of existing task definition in my AWS account and multiple cluster as well. Do I need to modify each task definition with the above dockerLabels config? or create a new one and again deploy the new container "prometheus-ecs-discovery"?

Please help me.

[Rudd-O]

Sorry but this is an issue tracker, not a support request forum. If it's getting no discovered exporters then there's probably a label matching issue.