docker-compose-prometheus-elasticsearch-mongo

Project to setup Prometheus Monitoring and Grafana to monitor Elasticsearch and MongoDB

What is this project for?

The goal of the project is to show how to set up all the components needed to monitor Elasticsearch and MongoDB. I'm using Prometheus for monitoring and Grafana for visualization. The project is not going to explain how to use or what is Prometheus and Grafana.

Let's go over the list of components that we need for the project.

List of components:

1. Prometheus
2. Grafana
3. MongoDB
4. Elasticsearch
5. MongoDB Prometheus Exporter
6. Elasticsearch Prometheus Exporter

What is the exporter

Learn more about exporters in Prometheus here.

What is the deployment process?

I'm using docker-compose to deploy all the components in one-go.

What is in the mongo-exporter folder?

The mongo-exporter doesn't yet have an official Container Image built. So the Dockerfile inside the mongo-exporter folder downloads the latest code from the GitHub repository, build & makes the binary, bundles the final image to use.

Let's take a look at what is in the docker-compose.yml file

version: '3.2'
services:
# elastic search component. exposing 9200 port
  elastic_search:
    restart: 'always'
    ports:
    - '9200:9200'
    image: elasticsearch
    container_name: elasticsearch-container
# setting the environment variable discovery.type=single-node to bring up a single node elasticsearch
    environment:
    - 'discovery.type=single-node'
# provide the network alias name to use it in the exporter
    networks:
      infranet:
        aliases:
        - 'elasticsearch-service'
# elasticsearch prometheus exporter to monitor the elasticsearch service. expose port 9108.
# We will use this information to configure the prometheus to listen.
  es_exporter:
    restart: 'always'
    ports:
    - '9108:9108'
    image: justwatch/elasticsearch_exporter
    container_name: es-exporter-container
# pass the elasticsearch url as an input to the exporter
    command:
    - '-es.uri=http://elasticsearch-service:9200'
# specify the depends on the elasticsearch so the docker brings up this service only after the elasticsearch is up.
# depends_on is not a full safe approach. read more about it here. 
# https://docs.docker.com/compose/startup-order/
    depends_on:
    - elastic_search
    networks:
      infranet:
        aliases:
        - elasticsearch-exporter-service
# mongodb service
  mongo:
    restart: 'always'
    ports:
    - '27017:27017'
    image: mongo
    container_name: mongo-container
    networks:
      infranet:
        aliases:
        - 'mongodb-service'
# setting up the mongodb exporter service. exposing the port 9001
  mongo_exporter:
    restart: 'always'
    ports:
    - '9001:9001'
# as you might have noticed, I'm using my personal repository. because as you know, the mongodb exporter is not 
# officially available as a container image. so i locally build it with the below name.
    image: gpuliyar/mongo-exporter
    container_name: mongo-exporter-container
# provide the mongodb service information for the exporter to work
    environment:
    - 'MONGO_SERVICE=mongodb-service'
    - 'MONGO_PORT=27017'
    depends_on:
    - mongo
    networks:
      infranet:
        aliases:
        - 'mongodb-exporter-service'
# start the grafana service
  grafana:
    restart: 'always'
    ports:
    - '3000:3000'
    image: grafana/grafana
    container_name: grafana-container
# start the prometheus service
  prometheus:
    restart: 'always'
    ports:
    - '9090:9090'
    image: prom/prometheus
    container_name: prometheus-container
    command:
    - '--config.file=/prometheus/config/prometheus.yaml'
    - '--storage.tsdb.path=/data'
    volumes:
    - ./config:/prometheus/config
    - ./data:/data
    depends_on:
    - activemq
    - es_exporter
    - mongo_exporter
    networks:
      infranet:
        aliases:
        - 'prometheus-service'
networks:
  infranet:

Let's try to understand what is in the config/promethues.yaml file

Read here to know more about Prometheus Configuration.

# global configuration 
global:
  scrape_interval: 15s
  evaluation_interval: 15s
# gloabl external labels for mapping
  external_labels:
    monitor: rnd
    environment: poc-environment
    service: prometheus
    region: local
    dc: local
# scrape configuration starts here
scrape_configs:
# configuration to monitor the prometheus service itself.
- job_name: prometheus
  scrape_interval: 30s
  scrape_timeout: 30s
  honor_labels: true
  static_configs:
  - targets: ['prometheus-service:9090']
# configuration to monitor the elasticsearch service by listening to elasticsearch exporter
- job_name: elasticsearch
  scrape_interval: 30s
  scrape_timeout: 30s
  honor_labels: true
  static_configs:
  - targets: ['elasticsearch-exporter-service:9108']
# configuration to monitor the mongodb service by listening to mongodb exporter
- job_name: mongodb
  scrape_interval: 30s
  scrape_timeout: 30s
  honor_labels: true
  static_configs:
  - targets: ['mongodb-exporter-service:9001']

Important note:

docker-compose command sometimes fails to bring up the prometheus service due to access permission to data folder. In that case, run the below command as a workaround.

chmod 777 data

That's it, job done!