Set up Prometheus with Docker Compose - docker-compose

Question

I am new to Prometheus and Docker Compose. I have a project structure with docker-compose.yml file that setup Prometheus and Grafana:
/prometheus-grafana/prometheus/docker-compose.yml
version: '3'
services:
prometheus:
image: prom/prometheus:v2.21.0
ports:
- 9000:9090
volumes:
- ./prometheus:/etc/prometheus
- prometheus-data:/prometheus
command: --web.enable-lifecycle --config.file=/etc/prometheus/prometheus.yml
grafana:
image: grafana/grafana:$GRAFANA_VERSION
environment:
GF_SECURITY_ADMIN_USER: $GRAFANA_ADMIN_USER
GF_SECURITY_ADMIN_PASSWORD: $GRAFANA_ADMIN_PASSWORD
ports:
- 3000:3000
volumes:
- grafana-storage:/var/lib/grafana
depends_on:
- prometheus
networks:
- internal
networks:
internal:
volumes:
prometheus-data:
grafana-storage:
I just added more config in /prometheus-grafana/prometheus/prometheus/prometheus.yml like this, the part that I added is the last 3 lines:
global:
scrape_interval: 30s
scrape_timeout: 10s
rule_files:
- alert.yml
scrape_configs:
- job_name: services
metrics_path: /metrics
static_configs:
- targets:
- 'prometheus:9090'
- 'idonotexists:564'
- job_name: myapp
scrape_interval: 10s
static_configs:
- targets:
- localhost:2112
I started Prometheus by running: docker-compose up -d, I got to Prometheus on http://localhost:9000/graph but I don't see the new config I added to prometheus.yml, in docker-compose.yml file, there is a line:
command: --web.enable-lifecycle --config.file=/etc/prometheus/prometheus.yml
Am I supposed to change this too refers to the path of my another /prometheus-grafana/prometheus/prometheus/prometheus.yml in my project instead of from /etc/prometheus/prometheus.yml as in reality, this file doesn't exist /etc/prometheus/prometheus.yml
Thank you in advance.

Answer 1

If you have prometheus configured with --config.file=/etc/prometheus/prometheus.yml it expects its config file to be at exact this position.
Since you have the the following mount points already configured:
volumes:
- ./prometheus:/etc/prometheus
- prometheus-data:/prometheus
you just need to put your config file into ./prometheus and name it prometheus.yml