Prometheus in Docker Container

In this lesson you’ll run Prometheus inside a Docker container. The workflow mirrors a non-containerized setup: pull the official prom/prometheus image, provide a prometheus.yml configuration file, bind-mount that file into the container, and expose Prometheus’ port (9090) on the host.

A simple flow diagram titled "Prometheus Docker" showing the prom/prometheus Docker image being pulled from DockerHub. It illustrates using a prometheus.yml configuration and then exposing ports and binding mounts for the container.

Overview:

Host stores prometheus.yml and a directory for TSDB data.
Docker runs prom/prometheus with the host config file bind-mounted into the container.
Port 9090 is mapped so the UI and API are reachable at http://localhost:9090.

1. Create the Prometheus configuration on the host

Create or edit prometheus.yml on your host. The configuration format is identical to bare-metal or VM installations. Example minimal config that scrapes Prometheus itself:

# prometheus.yml
global:
  scrape_interval: 15s

scrape_configs:
  - job_name: 'prometheus'
    static_configs:
      - targets: ['localhost:9090']

Save this file at a path you’ll use for the bind mount (for example /path/to/prometheus.yml).

2. Run Prometheus in Docker

Run the official Prometheus image and bind-mount the configuration file and a data directory. This example runs Prometheus detached, maps port 9090, mounts both the config file and a persistent data directory, and enables the lifecycle endpoint for HTTP-triggered reloads:

docker run -d \
  --name prometheus \
  -p 9090:9090 \
  -v /path/to/prometheus.yml:/etc/prometheus/prometheus.yml:ro \
  -v /path/to/prometheus-data:/prometheus \
  prom/prometheus \
  --config.file=/etc/prometheus/prometheus.yml \
  --storage.tsdb.path=/prometheus \
  --web.enable-lifecycle

3. Docker run flags — quick reference

Flag / Option	Purpose	Example
`-d`	Run container detached (in background)	`-d`
`--name`	Assign a human-friendly container name	`--name prometheus`
`-p HOST:CONTAINER`	Map host port to container port (access UI/API)	`-p 9090:9090`
`-v <host>:<container>:ro`	Bind-mount host config into container (read-only recommended)	`-v /path/to/prometheus.yml:/etc/prometheus/prometheus.yml:ro`
`-v <host-dir>:<container-dir>`	Persist TSDB storage on host	`-v /path/to/prometheus-data:/prometheus`
`--config.file`	Prometheus flag to specify the config file location inside the container	`--config.file=/etc/prometheus/prometheus.yml`
`--storage.tsdb.path`	Directory inside container where TSDB data will be stored	`--storage.tsdb.path=/prometheus`
`--web.enable-lifecycle`	Enable HTTP `/-/reload` endpoint for runtime config reloads	`--web.enable-lifecycle`

4. Lifecycle reload and useful commands

If you omit --web.enable-lifecycle, Prometheus will not respond to HTTP reload requests. Either restart the container after editing prometheus.yml (for example docker restart prometheus) or start Prometheus with --web.enable-lifecycle and trigger a reload by POSTing to http://localhost:9090/-/reload.

Useful commands:

Follow logs:
- docker logs -f prometheus
Restart container:
- docker restart prometheus
Trigger lifecycle reload (when --web.enable-lifecycle is enabled):

curl -X POST http://localhost:9090/-/reload

5. Verify Prometheus is running

Visit the UI at: http://localhost:9090
Check Status -> Targets to confirm configured scrape targets are UP.
Use logs (docker logs -f prometheus) for troubleshooting.

References and further reading

Prometheus docs: https://prometheus.io/docs/
Docker Hub: prom/prometheus — https://hub.docker.com/r/prom/prometheus

That’s it — the internal Prometheus configuration and behavior are identical to a non-containerized setup. Bind mounts keep the host config and data persistent and in sync with the container, while port mapping exposes the UI and API on the host.

Introduction

Observability Fundamentals

Prometheus Fundamentals

PromQL

Dashboarding & Visualization

Application Instrumentation

Service Discovery

Push Gateway

Alerting

Monitoring Kubernetes

Conclusion

Scaling & Long Term Storage

Prometheus in Docker Container

1. Create the Prometheus configuration on the host

2. Run Prometheus in Docker

3. Docker run flags — quick reference

4. Lifecycle reload and useful commands

5. Verify Prometheus is running

References and further reading

Watch Video

​1. Create the Prometheus configuration on the host

​2. Run Prometheus in Docker

​3. Docker run flags — quick reference

​4. Lifecycle reload and useful commands

​5. Verify Prometheus is running

​References and further reading

Watch Video

1. Create the Prometheus configuration on the host

2. Run Prometheus in Docker

3. Docker run flags — quick reference

4. Lifecycle reload and useful commands

5. Verify Prometheus is running

References and further reading