Install Prometheus using Docker

Overview

After completing installation of Docker on Windows in the previous tutorial, will see how to download a specific image or set of images using docker pull command.

Q: What is Prometheus?
Ans:

Prometheus is a free event monitoring and alerting software application. It logs real-time metrics in a time series database built with an HTTP pull model, allowing for flexible queries and real-time alerting.

What is Docker?

Docker is a set of platform as a service tools that deliver software in containers using OS-level virtualization. Containers are self-contained, containing their own software, libraries, and configuration files, and communicating with one another via well-defined channels. Docker makes it simple for developers to package, ship, and execute any application as a lightweight, portable, self-contained container that can operate almost anywhere.

Pull an image from Docker Hub

Use docker pull to download a specific image or set of images (i.e., a repository). If no tag is specified, Docker Engine defaults to the :latest tag. This command retrieves the latest image:

Using the docker pull command, you can get the Prometheus docker image -

$ docker pull prom/prometheus

The image ID is a SHA256 digest covering the image's configuration and layers, and Docker uses a content-addressable image store.

Multiple layers can be included in a Docker image. The image in the example above has below layers as shown.

Once the image has been downloaded, use the docker image ls command to see a list of all the images available locally.

C:\Users>docker image ls
REPOSITORY               TAG       IMAGE ID       CREATED        SIZE
prom/prometheus          latest    3313ec19d029   13 days ago    189MB
docker/getting-started   latest    083d7564d904   3 weeks ago    28MB
hello-world              latest    d1165f221234   4 months ago   13.3kB

Finally, we'll use Docker to run Prometheus. To start a Prometheus server in the background, type the following command:

$ docker run -d --name=prometheus -p 9090:9090 -v <PATH_TO_prometheus.yml_FILE>:/etc/prometheus/prometheus.yml prom/prometheus --config.file=/etc/prometheus/prometheus.yml

In this example, I have kept the file (prometheus.yml) at D drive. So I have replaced PATH_TO_prometheus.yml_FILE with D:\prometheus.yml.

However after executing the command, I encountered the error docker: Error response from daemon: Conflict. The container name "/prometheus" is already in use by container

C:\Users>docker run -d --name=prometheus -p 9090:9090 -v D:\prometheus.yml:/etc/prometheus/prometheus.yml prom/prometheus --config.file=/etc/prometheus/prometheus.yml
docker: Error response from daemon: Conflict.
The container name "/prometheus" is already in use by container "865ad37d121bfdb8819b5459637ff407d0bb40eb4a2fd93a739030e008ef919e".
You have to remove (or rename) that container to be able to reuse that name.
See 'docker run --help'.

To resolve above error use below command to Force to remove one or more containers.

docker rm -f prometheus

Now, use below docker command to run Prometheus.

docker run -d --name=prometheus -p 9090:9090 -v D:\prometheus.yml:/etc/prometheus/prometheus.yml prom/prometheus --config.file=/etc/prometheus/prometheus.yml

C:\Users>ipconfig

IPv4 Address. . . . . .  . . : 192.168.1.9

global:
  scrape_interval:     15s # Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.

rule_files:
# - "first_rules.yml"
# - "second_rules.yml"

# A scrape configuration containing exactly one endpoint to scrape:
scrape_configs:
  - job_name: 'prometheus'

    static_configs:
      - targets: ['127.0.0.1:9090']

  - job_name: 'spring-actuator'
    metrics_path: '/actuator/prometheus'
    scrape_interval: 5s
    static_configs:
      - targets: ['192.168.1.9:8080'] # refer system ip address rather that localhost