Prometheus configuration in tutorial leads to directory mount error

[BBITWestin]

Issue Description

Following the tutorial instructions for adding Prometheus results in an error where Prometheus attempts to read its configuration file but encounters a directory instead.

Current Behavior

When following the tutorial steps exactly as written, Prometheus fails to start with the following error:

level=ERROR source=main.go:593 msg="Error loading config (--config.file=/etc/prometheus/prometheus.yml)" file=/etc/prometheus/prometheus.yml err="read /etc/prometheus/prometheus.yml: is a directory"

The error keeps repeating and Prometheus exits with code 2.

Current Tutorial Configuration

docker-compose.yml section:

  prometheus:
    image: prom/prometheus
    container_name: prometheus
    command:
      - '--config.file=/etc/prometheus/prometheus.yml'
    ports:
      - 9090:9090
    restart: unless-stopped
    volumes:
      - ./prometheus:/etc/prometheus

Environment

• Following Microsoft Learn tutorial: https://learn.microsoft.com/en-us/training/modules/implement-observability-cloud-native-app-with-opentelemetry/6-exercise-use-opentelemetry-data-cloud-native-application

[alexsh134]

BBITWestin, You are right! Same issue here.
There is some issue mounting ./prometheus. volume into /etc/prometheus or locating prometheus.yml in local file system.

The workaround that worked for me:

1. In docker-compose.yml => comment out the command causing the issue
   command:
   - '--config.file=/etc/prometheus/prometheus.yml'
2. Start the container
3. In Docker Desktop locate and open prometheus container
4. Navigate to Files tab
5. Navigate to /etc
6. Right click on /etc and import /prometheus folder from your file system
7. Stop container
8. Uncomment the command in docker-compose.yml
9. Run "docker compose up"

Hopefully the container will start properly.