Docker image: Server listens to wrong ip

What's wrong?

When spinning up a new container for Alloy, the server listens to 127.0.0.1:12345 rather than 0.0.0.0:12345. This causes the requests to http://localhost:12345 from outside the container to fail (ERR_EMPTY_RESPONSE from Chrome, error 52 from curl).

This has an easy fix, bind the listening IP address of the Alloy server to 0.0.0.0:12345 rather than 127.0.0.1:12345, and it will be solved. I mitigated that by adding the below line to the docker-compose.yml: entrypoint: alloy run --server.http.listen-addr=0.0.0.0:12345 --storage.path=/var/lib/alloy/data /etc/alloy/config.alloy but it should be set like that by default.

Steps to reproduce

Created a docker-compose.yml as below:

grafana.alloy:
  image: grafana/alloy:latest
  volumes:
    - ./my-path-blah/config.alloy:/etc/alloy/config.alloy
  environment:
    OTEL_SERVICE_NAME: "blah"
    OTEL_RESOURCE_ATTRIBUTES: "deployment.environment=development,service.namespace=blah-blah,service.version=1"
  ports:
    - 12345:12345
    - 4317:4317 # OTLP gRPC receiver
    - 4318:4318 # OTLP http receiver

Also create a config.alloy as in the below configuration and save it under /my-path-blah

Run docker-compose up
Access http://localhost:12345
Observe ERR_EMPTY_RESPONSE by browser.

System information

Windows 11 with Docker Desktop 4.33.1

Software version

Grafana Alloy v1.3

Configuration

otelcol.receiver.otlp "default" {
    // configures the default grpc endpoint "0.0.0.0:4317"
    grpc { }
    // configures the default http/protobuf endpoint "0.0.0.0:4318"
    http { }

    output {
        metrics = [otelcol.processor.resourcedetection.default.input]
        logs    = [otelcol.processor.resourcedetection.default.input]
        traces  = [otelcol.processor.resourcedetection.default.input]
    }
}

otelcol.processor.resourcedetection "default" {
    detectors = ["env", "system"] // add "gcp", "ec2", "ecs", "elastic_beanstalk", "eks", "lambda", "azure", "aks", "consul", "heroku"  if you want to use cloud resource detection

    system {
        hostname_sources = ["os"]
    }

    output {
        metrics = [otelcol.processor.transform.add_resource_attributes_as_metric_attributes.input]
        logs    = [otelcol.processor.batch.default.input]
        traces  = [
            otelcol.processor.batch.default.input,
            otelcol.connector.host_info.default.input,
        ]
    }
}

otelcol.connector.host_info "default" {
    host_identifiers = ["host.name"]

    output {
        metrics = [otelcol.processor.batch.default.input]
    }
}

otelcol.processor.transform "add_resource_attributes_as_metric_attributes" {
    error_mode = "ignore"

    metric_statements {
        context    = "datapoint"
        statements = [
            "set(attributes[\"deployment.environment\"], resource.attributes[\"deployment.environment\"])",
            "set(attributes[\"service.version\"], resource.attributes[\"service.version\"])",
        ]
    }

    output {
        metrics = [otelcol.processor.batch.default.input]
    }
}

otelcol.processor.batch "default" {
    output {
        metrics = [otelcol.exporter.otlphttp.grafana_cloud.input]
        logs    = [otelcol.exporter.otlphttp.grafana_cloud.input]
        traces  = [otelcol.exporter.otlphttp.grafana_cloud.input]
    }
}

otelcol.exporter.otlphttp "grafana_cloud" {
    client {
        endpoint = "https://otlp-gateway-prod-eu-west-3.grafana.net/otlp"
        auth     = otelcol.auth.basic.grafana_cloud.handler
    }
}

otelcol.auth.basic "grafana_cloud" {
    username = "xxxxxx"
    password = "yyyyyy"
}

Logs

...
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.6795315Z level=info msg="finished complete graph evaluation" controller_path=/ controller_id="" trace_id=f891f5239e4d53d4798c6b55279ace51 duration=7.456871ms
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.679799052Z level=info msg="scheduling loaded components and services"
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.680297987Z level=info msg="starting cluster node" service=cluster peers_count=0 peers="" advertise_addr=127.0.0.1:12345
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.680580219Z level=info msg="peers changed" service=cluster peers_count=1 peers=01d9f3a2af2b
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.680634703Z level=info msg="now listening for http traffic" service=http addr=127.0.0.1:12345
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.680949941Z level=info msg="began detecting resource information" component_path=/ component_id=otelcol.processor.resourcedetection.default
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.681093243Z level=info msg="Starting host_info connector" component_path=/ component_id=otelcol.connector.host_info.default
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.681190634Z level=info msg="Starting GRPC server" component_path=/ component_id=otelcol.receiver.otlp.default endpoint=0.0.0.0:4317
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.681325674Z level=info msg="detected resource information" component_path=/ component_id=otelcol.processor.resourcedetection.default resource="map[deployment.environment:local host.name:01d9f3a2af2b os.type:linux service.namespace:xxxxx service.version:1]"
2024-08-14 08:09:44 ts=2024-08-14T05:09:44.681659156Z level=info msg="Starting HTTP server" component_path=/ component_id=otelcol.receiver.otlp.default endpoint=0.0.0.0:4318

grafana / alloy